JPH06324367A - Optical waveguide element and control therefor - Google Patents

Abstract

PURPOSE:To maintain an arbitrary refractive index, i.e., phase control state without requiring the energy from the outside at all by including an org. compd. which changes the refractive index of a core only by the irradiation with light of a specific wavelength region in a part of the core. CONSTITUTION:A high-polymer soln. of the org. compd. which changes the refractive index of the core only by the irradiation with the light of the specific wavelength region is injected into the core part and after the injected high- polymer soln. evaporates sufficiently, an optically polished quartz glass plate 6 is placed on the high-polymer core 8. The high-polymer core 8 softens and the excess component is extruded when this part is heated in a vacuum state and the quartz glass plate 6 is lightly pressed. The quartz glass plate 6 is closely contacted onto the high-polymer core 8. This quartz glass plate 6 acts as an upper clad. The high-polymer soln. of the org. compd. adjusted in the refractive index is injected only into the part right above the glass core 3, by which the high-polymer clad 9 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide element for controlling the phase of coherent light propagating through a core by changing the refractive index of the coherent light by irradiating light in a specific wavelength range and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, as an optical waveguide element for controlling the phase of coherent light propagating through a core by changing its refractive index, one utilizing a thermo-optical effect (TO effect) is known (for example, , Optronics, No. 8 (19
88) Masao Kawauchi, p. 85-90). In particular,
A heater is provided above the glass clad and a heat sink of a silicon substrate is provided below the glass clad, and a temperature distribution in which the temperature of the upper clad, the core, and the lower clad decreases in order is obtained by heating the heater by energizing the heater. The phase of light propagating through the core is changed by changing the refractive index depending on the distribution.
When trying to make the phase constant with the phase adjuster using this optical waveguide element, an accurate temperature maintaining device that constantly maintains the temperature distribution of the optical waveguide is required, and it is necessary to energize to maintain the temperature. There is a need to do.

Further, as another conventional optical waveguide element of this type, one utilizing an electro-optical effect (EO effect) is known (for example, Koshin era, No. 31 (199).
2), Guss Mohlmann, Shiro Nakamura, p. 1
~ 5, or Fourth Optoelectron
ics Conference (OEC'92) Tec
mechanical Digest, 17D3-4, Jul
y, (1992), G.I. R. Mohlmann).
Specifically, a secondary optical nonlinear organic polymer is used as a core, and an electric field is applied to the core to change its refractive index, thereby changing the phase of light propagating through the core. Using this optical waveguide device, a phase modulator, Mach-Zehnder interferometer, 2 × 2 directional switch
Optical devices integrated up to about 0 sets have been realized.

Further, recently, an example in which a photoreaction effect (OO effect) for controlling a refractive index by irradiating light is applied to an optical device has been reported (for example, IEICE Spring National Convention, C-. 217, (1990), Yujihito Kobayashi
Et al., P. 4-272, or IEICE Spring National Convention, C-292, (1991), Yuji Kobayashi et al., P.
4-309, or IEICE Spring National Convention, C
-646, (1992), T. Yoshida et al., P. 5-26
7, or JP-A-4-256907). In these, a photochromic organic material is used as a photorefractive index control material for the cladding of the optical fiber coupler to change the branching ratio of the coupler.

Furthermore, some mechanical self-holding type optical waveguide switches have been proposed (for example, Japanese Unexamined Patent Publication No. Hei 4)
However, since the mechanical optical waveguide switch is capable of only on / off operation and its self-holding property is limited to on / off operation, the phase of light propagating through the core is It's different from changing.

[0006]

The above-mentioned conventional optical waveguide device utilizing the TO effect and the EO effect enables high-speed phase control, but in any case, if the heat or the electric field is not continuously applied, the effect, that is, the phase There was a drawback that the control state disappeared.

In view of the above conventional problems, it is an object of the present invention to provide an optical waveguide device which can maintain an arbitrary refractive index, that is, a phase control state without requiring any energy from the outside. .

[0008]

According to the present invention, in order to achieve the above object, in an optical waveguide device for controlling the phase of coherent light propagating in a core by changing its refractive index, a part of the core is set to a specific wavelength. We propose an optical waveguide device composed of an organic compound in which the refractive index is controlled to an arbitrary value in response to light irradiation in a region and the refractive index is maintained as it is in light irradiation except in a dark place and the specific wavelength region.

That is, the invention according to claim 1 is an optical waveguide device comprising at least a core and a clad, wherein at least a part of the core has its refractive index changed only by irradiation with light in a specific wavelength range. It is characterized by containing an organic compound.

According to a second aspect of the present invention, there is provided an optical waveguide element comprising at least a core and a clad, wherein at least a part of the clad changes a refractive index of the clad only by irradiation with light in a specific wavelength range. It is characterized by containing an organic compound.

According to a third aspect of the present invention, there is provided an optical waveguide comprising at least a core and a clad, wherein at least one of the core and the clad contains an organic compound capable of changing the refractive index of the one only by irradiation with light in a specific wavelength range. A method of controlling an element, comprising irradiating light in the specific wavelength range from one end of the core, changing the refractive index of the core or the clad by the irradiation, and controlling the phase of light propagating in the core. Characterize.

According to a fourth aspect of the present invention, there is provided an optical waveguide comprising at least a core and a clad, wherein at least one of the core and the clad contains an organic compound capable of changing the refractive index of the one only by irradiation with light in a specific wavelength range. A method of controlling an element, irradiating light in the specific wavelength range from a direction orthogonal to an optical waveguide of the optical waveguide element, changing the refractive index of the core or clad by the irradiation, and propagating through the core. It is characterized by controlling the phase of.

[0013]

Table 1 shows the difference between the present invention and the prior art from the viewpoint of phase control.

[0014]

[Table 1]

As can be seen from Table 1, the present invention can maintain the phase state of light propagating through the core with no power for a long period of time as compared with the conventional phase control technique, and the state can be easily changed. It provides technology. Therefore, in actual use of the element, it does not matter whether the operation speed is fast or slow. When attempting to realize such a long-term holding of the phase state by the TO effect, a highly accurate temperature maintenance management device and long-term power supply are indispensable, resulting in a very uneconomical system. Also, in order to realize by the EO effect, a voltage for controlling the refractive index must be constantly applied, and a new device for maintaining the state is required, which is an extremely expensive system. Will be.

Further, there are self-holding type switches using optical fiber couplers utilizing the OO effect and mechanical self-holding type optical waveguide switches, but none of them cause any phase shift and their applications are It is different from the phase shift one. That is, in the example of the coupler using the photochromic organic material, its use is limited to the self-holding type optical switch having a changed branching ratio, and the setting, change and fine adjustment of the branching ratio. Further, in view of the physical properties of the organic compounds used therein, the thermal reverse reaction cannot be stopped at room temperature, and long-term self-holding property has not been realized. Further, the mechanical type is limited to the on / off operation of the ratio, and arbitrary phase adjustment cannot be performed.

The present invention relates to an optical waveguide device having a phase control function which enables self-holding operation for a long period of time by using the OO effect, and has a phase control function using the conventional TO effect and EO effect. It differs from the optical waveguide device in that it is not necessary to forcibly perform the operation for maintaining the phase from the outside. Further, the conventional long-term self-holding type optical switch is only a mechanical switch, and is different in that it is not an operation of phase control, that is, the mechanical switch can only perform an on / off operation.

Further, the present invention is not limited to the application to a silica-based optical waveguide, but a photochromic material is used for a core or a clad of a semiconductor optical waveguide, a dielectric optical waveguide, an amorphous optical waveguide other than a silica optical waveguide, or the like. It can be loaded and a similar operation is possible.

The organic compound used in the present invention is not particularly limited as long as it is a material whose refractive index can be controlled by irradiation with light. For example, photolysis reaction, photodissociation reaction, photodimerization reaction, photoisomerization reaction, photochromic reaction. An organic material that causes the like can be used. However, an organic material that induces a photochromic reaction is preferable in that the reversible refractive index can be controlled, and the best results have been obtained with the photochromic material having a diarylethene structure as far as the inventors investigated.

These organic compounds are usually solid at room temperature, and when used as a core material of an optical waveguide, they are mixed with an organic polymer or dissolved in an organic solvent, or the side chains of the organic polymer are chemically bonded. Used in combination. When such an organic compound is used as the core of the optical waveguide, matching of the refractive index with the optical waveguide is important. In particular, a silica-based optical waveguide requires a lower refractive index than an ordinary organic compound, but the results of studies conducted by the inventors indicate that a fluorinated organic polymer, a fluorine-based organic solvent, or a silicon-based organic solvent is used. , Matching was easily realized.

The method of forming the core of the optical waveguide using the organic compound as the core layer is not particularly limited, and light may be transmitted as the core of good quality. Since the core is covered with the quartz glass clad, influences from the environment such as moisture proof and natural oxidation are extremely small, but treatments such as passivation and sealing may be added for the purpose of ensuring reliability.

The method of forming the organic compound as a cladding layer on the core portion of the waveguide is not particularly limited, and any forming method can be used as long as it can cover the core portion as a good quality cladding layer. Even when an organic compound is used for the clad layer, the entire waveguide may be covered and the phase of the waveguide may be controlled by irradiating the portion where the refractive index needs to be changed with light, but only the portion for phase control has the refractive index. The core part may be covered with the control organic compound, and the other part may be a usual clad layer. Further, in order to balance the phase control, an organic material whose refractive index is adjusted and fixed at an arbitrary position of the core may be used as the cladding layer. The clad layer thus produced may be subjected to a treatment such as passivation or sealing for the purpose of reducing influences from the environment such as moisture proof and natural oxidation, if necessary.

In the optical waveguide element of the present invention in which the above-mentioned organic compound is contained in the core or the clad, the method of controlling the phase of the coherent light propagating through the core is as follows: Examples include a method of irradiating light in a specific wavelength range from one end or a direction orthogonal to the optical waveguide to change the refractive index and control the phase.

The present invention will be described below with reference to examples. However, the present invention is not limited to this, and any optical waveguide element that requires phase control can be used.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the optical waveguide device of the present invention, and here shows an example in which a Mach-Zehnder type 2 × 2 optical switch with a directional coupler is realized. In the figure,
1 is a cylinder substrate, 2 is a silica glass clad produced by the flame deposition method, 3 is a silica glass core produced by the same method (9 μm)
m × 9 μm, Δn = 0.3%), 4 and 5 are 3 dB directional couplers, 6 is a quartz glass plate, 7 is a polymer core added with 10 (wt)% of a photochromic material, and 8 is a photochromic material. A polymer core to which no material is added, A and B are light entrance ports, C and D are light exit ports, E is a Mach-Zehnder first arm, and F is a Mach-Zehnder second arm.

FIG. 2 is an enlarged sectional view in the direction of arrow aa in FIG. 1, and FIG. 3 is an enlarged sectional view in the direction of arrow bb in FIG. The length of each of the polymer core and 8 is 5 mm, the length of the entire device is 40 mm, and the width is 4.5 mm.

In order to manufacture this, first, a Mach-Zehnder interfering circuit with a 2-input 2-output directional coupler is manufactured by a conventional flame deposition method, and thereafter, a reactive part is provided at the center of two arms of the Mach-Zehnder. Ion etching (RI
E) Using an apparatus, etch along the core with a width of 2 mm and a length of 5 mm up to the top of the core. Next, only the core portions of both arms have a core width of 9 μm, a length of 4 mm and a depth of 9 μm, and are etched so as to hollow out the core portions.

Next, as a core material, a polymer solution of a copolymer of fluorinated methyl methacrylate and methyl methacrylate, the refractive index of which was adjusted to 1.448 at a wavelength of 1.5 μm, was injected into the core portion of the first arm E. Then, similarly, a photochromic material (here, a diarylethene having a perfluorocyclopentene ring was used) was used in an amount of 10 (weight).
% And the refractive index at a wavelength of 1.5 μm is 1.44
The polymer solution adjusted to be 8 is injected into the core portion of the second arm F. After the solvent of the injected polymer solution is sufficiently evaporated, a quartz glass plate 6 whose upper and lower surfaces are 4.6 mm long, 1.9 mm wide, and 0.2 mm long is optically polished on the polymer cores 7 and 8. Put on.

Next, this portion is heated to 120 ° C. to 1 in a vacuum state.
When heated to 40 ° C. and lightly pressed the quartz glass plate 6, the polymer cores 7 and 8 are softened and the excess is extruded,
The quartz glass plate 6 is tightly adhered onto the polymer cores 7 and 8 without any gap, and the quartz glass plate 6 becomes an upper clad.

In the above structure, the exposed portion of the core is caused by a slight gap between the quartz glass plate 6 and the clad 2 of the element body in the light traveling direction. Therefore, the refractive index is adjusted only just above the glass core 3. The polymer solution of the fluorinated PMMA is injected to form the polymer clad 9. Then, a cyanoacrylate-based or epoxy-based adhesive 10 is injected into the concave portion around the quartz glass plate 6 to sufficiently bond it to the substrate. As a result, the polymer cores 7 and 8 are shielded from external influences of moisture, oxygen, other reactive gases, etc., and long-term stability can be guaranteed. Furthermore, the self-holding property of the refractive index of the photochromic material used is extremely excellent.
It is known to have stability at 0 ° C for 3 months or more.

In order to operate this, an ultraviolet light source and a visible light source for causing a photoreaction in the polymer core 7 are required. As a light incident method that causes a photoreaction to the polymer core 7, there are a method of injecting light from the outside such as an upper surface of an optical waveguide and a method of injecting light by propagating the core. For convenience, there is a method of making xenon strobe light incident from the upper surface of the optical waveguide. Xenon strobe (eg Matsushita Electric PE
(1120CT, etc.) is removed, and an ultraviolet bandpass filter (for example, UVD) is used as an ultraviolet light source instead.
33S, Toshiba glass, etc.) and an ultraviolet cut filter (for example, Y-50, Toshiba Glass, etc.) as a visible light source are prepared. This light source operates with two dry batteries and is convenient to carry.

Next, a single mode fiber is connected to each of the light incident port A and the light emission ports C and D.
Light from a laser diode (wavelength: 1.55 μm, output: 1 mW) is incident on the optical fiber of the groove A of the light incident port, and the optical fibers of the light emission ports C and D are two-input GaA.
s It was connected to the light receiving device. The light output from light output port C is 900 μW, and the light output from light output port D is 10 μw
Met.

Next, when a strobe equipped with an ultraviolet bandpass filter was flashed once from above the quartz glass plate 6, the light output of the light output port C immediately became 10 μW and the light output of the light output port D was 900 μW. Became. This state did not change without light irradiation. One minute later, when the strobe equipped with the UV cut filter was flashed once, the light output of the light emission port C was promptly 9%.
00 μW, and the optical output of the light output port D is 10 μW
Became. This is shown in FIG. As a result, the optical switch is capable of self-holding operation and has an extinction ratio of -19.5d.
B, the insertion loss was found to have a characteristic of 0.46 dB.

Further, even if the optical switch was left in a dark place for one month or more, the fluctuation of the optical output of 900 μW was within 0.1%, which showed good stability. Also, set the ambient temperature to -2.
Even in a heat cycle test (cycle time of 1 hour) in which the temperature was changed from 0 ° C. to 60 ° C., the fluctuation of the light output was within 0.1% after 500 cycles or more, showing good stability.

On the other hand, visible light and ultraviolet light, which are control lights, are transmitted through a single mode fiber and combined with a signal light (wavelength 1.3 or 1.5 μm) by a 3 dB fiber coupler immediately before an optical switch to obtain a high light. There is a way to lead to molecular cores 7 and 8.

The core 3 together with the signal light from the light incident port A
After passing through the 3 dB directional coupler 4, the control light incident on is incident on the cores of the Mach-Zehnder first arm E and the Mach-Zehnder second arm F, and the phase of only the second arm F in which the photochromic material exists. Change. Here, helium neon laser light (633 nm, 3 mW) and helium cadmium laser (325 nm, 10 mW),
Mercury xenon lamp (313nm, 50mW, 365n
m, 100 mW) or pulsed nitrogen laser (337
nm) with a fiber coupler and transmitted to just before the optical switch with a single-mode fiber of 10 m. Further, a signal light (wavelength 1.55 μm is used with the fiber coupler.
m, 1000 μW) and directly incident on the core 3.

When the visible light and the ultraviolet light which are the control light are not irradiated, the light emission port C is in the ON state (900 μm).
W) and the light emission port D was in the off state (10 μW). After 1 minute, irradiation with a helium-cadmium laser was performed for 5 seconds. Immediately, the light emission port C was turned off and the light emission port D was turned on. This state did not change without light irradiation. After a further 1 minute, irradiation with a helium neon laser was carried out for 5 seconds through an optical fiber. As a result, the light emitting port C returned to the on state and the light emitting port D returned to the initial state. The output light could be further changed by increasing the light irradiation time of the control light. At this time, a phase shift of 4π radians was observed as the maximum value. Therefore, at 2π and 4π radians, the output light was in the same state as when the control light was not emitted.

As described above, it has been found that the control light can also be transmitted through the optical fiber, and the self-holding type switching can be performed by the remote operation using only the light.

FIG. 5 shows a second embodiment of the optical waveguide device according to the present invention. Here, an example in which a self-holding type optical frequency multiplex demultiplexer is realized is shown. In the figure, 11 is a silicon substrate,
12 is a lower cladding, 13 is an upper cladding, 14 is a core, 15 and 16 are 3 dB directional couplers, 17 is a quartz glass plate, 18 is a photochromic-doped polymer core, A and B are light incident ports, and C and D. Is the light output port, G
Is a lower arm and H is an upper arm.

In order to fabricate this, first, a silica glass waveguide is fabricated by the conventional flame deposition method, and the core portion of the polymer core 18 and the upper cladding 13 around it are reacted in the same manner as in the first embodiment. Etching is performed by the ionic etching method, and a polymer solution containing a photochromic material (refractive index is matched with that of the silica glass core 14) is injected into this core portion. After sufficiently evaporating the solvent of the injected polymer solution, a quartz glass plate 17 is placed on this, the whole is heated to 140 ° C. in an inert gas, and the quartz glass plate 17 is pressed to form an upper clad. To do.

In the above structure, the exposed portion of the core is caused by a slight gap between the quartz glass plate 17 and the cladding 13 of the element body in the traveling direction of the light.
A polymer solution of fluorinated PMMA having a controlled refractive index is injected immediately above the substrate to form a polymer clad (not shown). Then, a cyanoacrylate-based or epoxy-based adhesive (not shown) is injected into the concave portion around the quartz glass plate 17 to sufficiently bond it to the substrate. By this,
The polymer core 18 is shielded from external influences such as moisture, oxygen, and other counter gases, so that long-term stability can be guaranteed.

To operate this, a xenon strobe was used with a different filter as in the first embodiment.

Further, a single mode fiber is connected to each of the light incident port A and the light emission ports C and D.
DFB-LD (wavelength: 1.55 μm) for light incident port A
Light is introduced and the frequency is changed by the injection current or the temperature. Assuming that the optical path difference between the two arms G and H is ΔL, when ΔL = 1 cm, Δf (= f1−f2) is 0.
It became 04 nm (5 GHz). When the wavelength of the DFB-LD was swept, the light output port C had a light output when the wavelength was 1.51 nm, and the light output port D had a light output when the wavelength was 1.55 nm. Insertion loss at this time is 2.5
The dB and the crosstalk were 17 dB.

Next, when a strobe equipped with an ultraviolet bandpass filter was made to flash once from above the quartz glass plate 17, light with a wavelength of 1.52 μm was output to the light output port C, and to the light output port D. Light having a wavelength of 1.55 μm was output. This state is the photochromic-added polymer core 18
The refractive index was changed, and ΔL was effectively lengthened, which was the same effect, and the wavelength interval could be changed. This state was stable when left in the dark and had self-holding property.

When the quartz glass plate 17 was irradiated with visible light, Δf quickly returned to the original 5 GHz state. By appropriately changing the irradiation amount of ultraviolet rays and the irradiation amount of visible rays, an optical frequency multi-polymer wave demultiplexer capable of self-holding an arbitrary wavelength interval could be constructed. The self-holding Δf was an arbitrary frequency from 1 GHz to 1 THz.

Furthermore, even when the optical frequency multiplex wave splitter was left in a dark place for several months or more, the optical output showed a good stability of 0.1% or less. Also, set the ambient temperature to -2.
Even in a heat cycle test (cycle time of 1 hour) in which the temperature was changed from 0 ° C. to 60 ° C., the fluctuation of the light output was within 0.1% after 500 cycles or more, showing good stability.

It was also found that the wavelength selection region can be reset by the control light transmitted through the optical fiber, as in the first embodiment.

[Embodiment 3] FIG. 6 shows a third embodiment of the optical waveguide device of the present invention, in which 21 is a quartz glass substrate.
22 is a quartz glass plate, 23 and 26 are 3 dB directional couplers, 24 is a photochromic material-added polymer core, 25
Is a polymer core, 27 is a light absorber-added polymer core, I and J are light entrance ports, K and L are light exit ports, M is a Mach-Zehnder first arm, and N is a Mach-Zehnder second arm.

FIG. 7 is an enlarged sectional view taken along line cc of FIG. 6 and FIG. 8 is an enlarged sectional view taken along line dd of FIG. FIG. 7 is a cross section of the Mach-Zehnder arm part, and the polymer to which the photochromic material is added is used only for the second arm N on the left, and its length is 5 mm. FIG. 8 shows a cross section of the central part of a 3 dB directional coupler, where the left and right cores are closer together and the core material is made of the same additive-free polymer. The entire element has a length of 50 mm and a width of 5 mm.

In order to manufacture this, the surface of the quartz plate manufactured by the conventional melting method is optically polished, and the core portion is 8 μm × so that a Mach-Zehnder interferometer with a 2-input 2-output directional coupler can be constructed. A recess of 8 μm is formed by a reactive ion etching (RIE) device. Next, as a functional core material, a photochromic material (here, a diarylethene having a perfluorocyclopentene ring was used) was added to a polymer (copolymer of fluorinated methylmethacrylate and methylmethacrylate) having a refractive index of 1% by weight. The polymer solution whose refractive index is adjusted so as to be 0.448 (wavelength 1.55 μm) has a constant length (5
mm) as a polymer solution. Next, as a light absorber, 1% by weight of an ultraviolet absorber (maximum absorption wavelength 353 nm, trade name Tinuvin 326) and 1% by weight of a visible light absorber (maximum absorption wavelength 550 nm, trade name Disperse First Violet 5R) Both were mixed with a polymer (copolymer of fluorinated methyl methacrylate and methyl methacrylate). The polymer solution was applied to the light absorber-containing polymer core portion 27 having a length of 5 mm. The refractive index of the polymer after drying is 1.
The wavelength is adjusted to 448 (wavelength 1.55 μm).

A solution of a copolymer of fluorinated methyl methacrylate and methyl methacrylate (refractive index 1.448, wavelength 1.55 μm) was applied to the entire remaining core portion including the first arm M. After the solvent of the injected polymer solution is sufficiently evaporated, a quartz glass plate 22 having the same size as the substrate is gently placed from above.

Next, this portion is heated to 120 ° C. to 14 ° C. under vacuum.
When heated to 0 ° C. and pressed against the quartz glass plate 22, the polymer softens and the excess is pushed out, and the quartz glass plate 22 adheres to the polymer core without any gaps.
2 is an upper clad. At this time, an epoxy adhesive is thinly applied to the glass interface other than the polymer core portion to increase the adhesive strength between the quartz glass substrate 21 and the quartz glass plate 22 and protect the waveguide from the external environment such as humidity. Finally, the end faces of the entrance port and the exit port were optically polished to reduce the connection loss.

In order to operate this, as in the first embodiment, an optical signal is introduced from the light incident port I or J through an optical fiber, and control light is emitted from the upper surface of the quartz glass plate 22 to generate an optical signal. It can be switched to one of the light emission ports K and L. Further, in the first embodiment, since the substrate was made of silicon, it was impossible to irradiate the control light, which was visible ultraviolet light, from the substrate side. However, in this embodiment, the substrate is made of quartz glass. Light control is also possible from the bottom. Therefore, the arrangement of the control light emitting device is facilitated.

Next, an operation method by remote control using control light will be described. As a light source for remote control, a light emitted from a mercury xenon lamp (200 W, 1600 mW / cm ² ) for ultraviolet rays is passed through a 365 nm band pass filter (band width 10 n
After passing through m) to make it monochromatic, it was directly made incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity 1 m after entering the fiber was 150 mW. On the other hand, for the visible light, the irradiation light from the xenon lamp (200 W) was passed through a bandpass filter (bandwidth 5
(0 nm) to obtain a monochromatic light, which was then directly incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity at 1 m after fiber incidence is 20
It was mW. Combine the optical fibers for ultraviolet and visible light into one quartz fiber with a fiber coupler,
As a result of 1 km optical transmission, an optical output of 0.9 mW was obtained with ultraviolet rays, and an optical output of 0.6 mW was obtained with visible light.

The control optical fiber was connected to the entrance port J of the optical waveguide device, one single mode fiber for signal light was connected to the entrance port I, and single mode fibers were also connected to the exit ports K and L, respectively. Light from a laser diode (wavelength 1.55 μm, output 1 mW) was made incident on the incident port I, and the optical fibers at the emission ports K and L were respectively connected to two GaAs light receiving devices. The light output from the emission port K was 900 μW, and the light output from the emission port L was 10 μW. Next, when the irradiation light of the mercury-xenon lamp was irradiated with the shutter opened for 10 seconds, the light output of the emission port L immediately became 900 μW and the light output of the emission port K became 10 μW. After this state was maintained for 10 minutes, the irradiation light from the xenon lamp was irradiated for 10 seconds in the same manner.
Optical output of 900 μW, and the optical output of the emission port L became 10 μW. This state was equivalent to that shown in FIG. 4 of the first embodiment.

It is not preferable for optical signal processing that the control light (356 nm, 550 nm) guided for controlling the refractive index is emitted from the emission ports K, L. For this purpose, the light absorbent-added polymer core portion 27 is arranged so as to absorb the ultraviolet light and the visible light and allow only the signal light to pass therethrough.
It was installed just before L. The attenuation of ultraviolet light was 70 dB and the attenuation of visible light was 83 dB. On the other hand, in the communication wavelength band, the insertion loss was at most 0.1 dB. By constructing the filters on the side of the light emission ports K and L as described above, it is possible to eliminate the adverse effect on the optical signal and at the same time remove the instability of the element operation due to the incidence of ultraviolet light and visible light from the emission light port. As a result, the self-holding optical switch has a high reliability and an extinction ratio of −19.
It was found that the switch characteristics were 5 dB and insertion loss: 0.58 dB. Moreover, it has been found that it is possible to control a remote optical switch of 1 km using a silica optical fiber.

Further, even if the optical switch was left in a dark place for one month or more, the fluctuation of the optical output of 900 μW was within 0.1%, which showed good stability. Also, set the ambient temperature to -20 ° C.
In a heat cycle test (cycle time of 1 hour) changed from 1 to 60 ° C., the light output fluctuation rate was within 0.1% and good stability was shown after 500 cycles or more.

[Fourth Embodiment] FIG. 9 is a view for explaining a fourth embodiment of the optical waveguide device of the present invention, in which 31 is a plastic substrate, 32 is a plastic plate, and 33 and 36 are 3.
dB directional coupler, 34 is a photochromic material-added polymer core, 35 is a polymer core, 37 is a light absorber-added polymer core, O and P are light entrance ports, Q and R are light exit ports, and S is The Mach-Zehnder first arm and T are the Mach-Zehnder second arm. The cross section of FIG. 9 has the same cross sectional shape as that of FIGS. 7 and 8 showing the third embodiment. However, the clad including the substrate is made of plastic instead of quartz glass.

The plastic substrate 31 is a core recess (8 μm).
m × 8 μm) was formed by injection mold molding using a precision mold so that a 3 dB directional coupler, a Mach-Zehnder arm, and a waveguide can be configured. Similarly, the plastic plate 32 is also formed as a flat plate by injection molding. A polyolefin thermoplastic resin having a low refractive index and excellent stability was used as the plastic material. Here, poly 4-methyl 1-pentene (refractive index 1.46) and low density polyethylene (refractive index 1.51) were used. In addition to this, polyvinylidene fluoride (refractive index 1.41), which is a fluorine-based resin, was also used.

Next, a core using a polymer (copolymer of fluorinated methyl methacrylate and methyl methacrylate) containing 10% by weight of a photochromic material (here, a diarylethane having a perfluorocyclopentene ring was used) was prepared. Therefore, a polymer solution was prepared in which the refractive index was adjusted so that the core-clad refractive index difference (Δn) was 0.3% after the polymer was dried. This polymer solution was applied as a polymer solution on the fixed length (5 mm) of the second arm T. Next, as a light absorber, 1% by weight of an ultraviolet absorber (maximum absorption wavelength 353 nm, trade name Tinuvin 326) and 1% by weight of a visible light absorber (maximum absorption wavelength 550 nm, trade name Disperse First Violet 5R) It was mixed with a solution of a polymer (a copolymer of fluorinated methyl methacrylate and methyl methacrylate). At this time, the copolymerization ratio of the polymer was adjusted, and the refractive index was adjusted so that Δn was 0.3% after drying. This polymer solution was applied to a light absorber-containing polymer core portion 37 having a length of 5 mm.

Δ over the rest of the core including the first arm S
A solution of a polymer (copolymer of fluorinated methyl methacrylate and methyl methacrylate) in which n was adjusted to 0.3% was applied. After the solvent of the injected polymer solution is sufficiently evaporated, a plastic plate 32 of the same size as the substrate is gently placed from the top.

Next, this part is heated to 70 ° C. to 80 ° C. under vacuum.
When the plastic plate 32 is pressed and heated, the polymer core portion is softened and the surplus portion is pushed out, the plastic plate 32 is closely adhered onto the polymer core without a gap, and the plastic plate 32 becomes the upper clad.

Further, the surface other than the polymer core was lightly roughened with an ion asher, and a thin epoxy adhesive was applied between the plastic plates to bond the plastic substrate 31 and the plastic plate 32 together. As a result, it was found that the polymer of the waveguide can be protected from not only mechanical strength but also external environment such as humidity.

To operate this, as in the first embodiment, an optical signal is introduced into the optical signal from the light incident port O or P, and control light is emitted from the upper surface of the plastic plate 32,
The optical signal can be switched to either the light output port Q or R. At this time, in the first embodiment, since the substrate was made of silicon, it was impossible to irradiate the control light, which was visible ultraviolet light, from the substrate side. However, in this embodiment, since the substrate is made of plastic, The light can be controlled even from the bottom, which facilitates the arrangement of the control light emitting device.

Next, an operation method by remote control using control light will be described. As a light source for remote control, a light emitted from a mercury xenon lamp (200 W, 1600 mW / cm ² ) for ultraviolet rays is passed through a 365 nm band pass filter (band width 10 n
After passing through m) to make it monochromatic, it was directly made incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity 1 m after entering the fiber was 150 mW. Irradiation light from a xenon lamp (200 W) for visible light is passed through a bandpass filter (bandwidth 50 n) of 550 nm.
After passing through m) to make it monochromatic, it was directly made incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity 1 m after the fiber was incident was 20 mW.

Optical fibers for ultraviolet rays and visible rays were put together into one quartz fiber by a fiber coupler and connected to a communication optical fiber. As a result of 1 km optical transmission, an optical output of 0.9 mW was obtained with ultraviolet rays, and an optical output of 0.6 mW was obtained with visible light. In particular, the silica single mode fiber for communication can be used together with the signal light without installing a control optical fiber. This fiber was connected to the entrance port I of the optical waveguide device. Single mode fibers are connected to the emission ports Q and R, respectively. Laser diode (wavelength 1.55 μm, output 100
An optical output of 5 μW) was made incident at the control light incident point, and optical transmission of 1 km was performed using the same single mode fiber that transmits the control light. Incident port I due to attenuation in optical fiber
The light intensity was 1000 μW. Output port Q, R
Each of the optical fibers was connected to two GaAs light receiving devices. The light output from the emission port Q was 900 μW, and the light output from the emission port R was 10 μW. Next, when the irradiation light of the mercury-xenon lamp was irradiated with the shutter opened for 10 seconds, the light output of the emission port L immediately reached 900.
μW, and the optical output of the emission port Q became 10 μW. When this state was maintained for 10 minutes, the irradiation light of the xenon lamp was irradiated for 10 seconds in the same manner. This time, on the contrary, the optical output of the emission port Q became 900 μW, and the emission port R
Optical output of 10 μW. This state was equivalent to that shown in FIG. 4 of the first embodiment.

It is not preferable for optical signal processing that the control light (356 nm, 550 nm) guided for controlling the refractive index is emitted from the emission ports K, L. For this purpose, the light absorbent-added polymer core portion 27 is arranged so as to absorb the ultraviolet light and the visible light and allow only the signal light to pass therethrough.
It was installed just before L. The attenuation of ultraviolet light was 70 dB and the attenuation of visible light was 83 dB. On the other hand, in the communication wavelength band, the insertion loss was at most 0.1 dB. By arranging the filters on the side of the light emission ports K and L in this way, it is possible to eliminate the adverse effect on the optical signal and at the same time remove the instability of the device operation due to the incidence of ultraviolet light and visible light from the emission light port. . As a result, the optical switch having this self-holding property has a high reliability and an extinction ratio of -1.
It was found that the switch characteristics were 9.5 dB and insertion loss: 0.58 dB. Moreover, it has been found that it is possible to control a remote optical switch of 1 km using a silica optical fiber.

Further, even when the optical switch was left in a dark place for one month or more, the fluctuation of the optical output of 900 μW was within 0.1%, which showed good stability. Also, set the ambient temperature to -20 ° C.
In a heat cycle test (cycle time of 1 hour) changed from 1 to 60 ° C., the light output fluctuation rate was within 0.1% and good stability was shown after 500 cycles or more.

[Embodiment 5] FIG. 10 shows a fifth embodiment of the optical waveguide device of the present invention, in which an optical remote control type optical frequency filter is realized. Since the photochromic material using this element has bistability, it can perform self-holding operation. In the figure, 41 is a silicon substrate, 42 is a lower clad, 43 is an upper clad, 44 is a core, 45
And 46 are 3 dB directional couplers, 47 and 50 are quartz glass plates, 48 is a photochromic-doped polymer core, 4
Reference numerals 9 and 52 are polymer clads, 51 is a light absorbent-added polymer core, U and V are light input ports, W and X are light output ports, Y is an upper arm, and Z is a lower arm.

In order to fabricate this, first, a silica glass waveguide was fabricated by the fire deposition method, and the core portion of the photochromic-doped polymer core 48 and the upper cladding 43 around it were reacted in the same manner as in the first embodiment. Etching is performed by a reactive ion etching method, and a polymer solution containing a photochromic material (diarylethene-based photochromic material) added to the former core portion is injected into the core portion. At the same time, the core part of the light absorbent-added polymer core 51 and the upper clad 43 around the core part are etched by the reactive ion etching method, and the light absorbent (UV absorber TINUVIN 326 and visible light absorber disperse) is attached to this core part. Inject the polymer solution to which the first violet 5R) was added. After drying, the refractive index of these polymer cores is
The material composition is adjusted so that

In the above-mentioned manufacturing, since a core exposed portion is generated due to a slight gap between the quartz glass plates 47 and 50 and the upper clad 43 of the element body in the light traveling direction, the refractive index is adjusted especially right above the glass core 44. Fluorinated PMMA
Is injected to form the polymer clads 49 and 52. After that, a cyanoacrylate-based or epoxy-based adhesive (not shown) is injected into the concave portions around the quartz glass plates 47 and 50 to sufficiently bond them to the substrate. As a result, the polymer cores 48 and 51 are shielded from external influences such as moisture, oxygen and other reactive gases, and long-term stability can be guaranteed.

Similar to the third embodiment, as a control light source,
Mercury xenon lamp for ultraviolet rays (200W, 1600m
Irradiation light of W / cm ² ) was passed through a 365 nm band-pass filter (band width 10 nm) to obtain a monochromatic light, which was then directly incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity 1 m after the fiber was incident was 10 mW. Xenon lamp for visible light (20
The irradiation light (0 W) was passed through a bandpass filter (bandwidth 50 nm) of 550 nm to make it monochromatic, and was then directly incident on a silica single mode fiber for optical communication by a lens collimator system. The optical output intensity at 1 m after fiber incidence is 2
It was 0 mW.

Optical fibers for ultraviolet rays and visible rays are combined into one quartz fiber by a fiber coupler, and
As a result of performing km optical transmission, an optical output of 0.9 mW was obtained with ultraviolet light, while an optical output of 0.6 mW was obtained with visible light. This control optical fiber was connected to the entrance port U of the optical waveguide device. On the other hand, one single-mode fiber for signal light is connected to the entrance port V, and single-mode fibers are connected to the exit ports W and X, respectively.

Light from a DFB laser diode (wavelength: 1.55 μm) was introduced into the incident port V, and the frequency was changed by the injection current or the temperature. Assuming that the optical path difference between the two arms Y and Z is ΔL, when ΔL = 1 cm, Δf (=
f1-f2) was 0.04 nm (5 GHz). D
When the wavelength of the FB-laser diode was swept, the light output was at the emission port W when the wavelength was 1.51 nm, and the light output was at the emission port X when the wavelength was 1.55 nm.
The insertion loss at this time is 2.5 dB, and the crosstalk is 17 d.
It was B.

Next, when the shutter of the ultraviolet light source was opened for 20 seconds, light of 1.52 μm appeared at the emission port W and light output of 1.55 μm appeared at the emission port X. This state is the same as the effect that the effective refractive index of the photochromic polymer core was changed and ΔL was effectively lengthened, and an optical remote control type variable optical frequency filter was realized. The self-holding Δf was an arbitrary optical frequency from 1 GHz to 1 THz.

The ultraviolet rays and visible light were not emitted to the emission ports W and X due to the absorption effect of the polymer core portion containing the light absorber. The insertion loss at 1.3 μm and 1.55 μm here was within 0.1 dB.

Further, the optical remote control type variable optical frequency filter showed a good stability in which the optical output fluctuation with respect to a constant frequency was within 0.1% after several months in the dark. Also,
Even in a heat cycle test (cycle time of 1 hour) in which the ambient temperature was changed from −20 ° C. to 60 ° C., the light output fluctuation rate was within 0.1% and good stability was shown after 500 cycles or more.

In this embodiment, the groove portion to be the core portion is penetrated to both ends of the substrate, but it is also possible to form a box-shaped groove 48a in which the lower clad 42 is left by several μm at the end portion of the substrate 41 (FIG. 11). reference). In the case of such a box-shaped groove, since the end portion of the core is a flat surface suitable for optical coupling, there is an effect of reducing loss.

[Sixth Embodiment] FIG. 12 is a view for explaining a sixth embodiment of the optical waveguide device of the present invention. 61 in the figure
Is a silicon substrate, 62 is a lower quartz glass clad produced by the flame deposition method, 63 is a core produced by the same method (9 μm × 9 μm, Δn = 0.3%), 64 is an upper glass clad, and 65 is a Y-branch core. , 66 is a polymer clad, and 67 is a polymer clad in which a photochromic material is added to the material of the polymer clad 66 by 10% by weight. The size of the element is 80 mm in length and 4.5 mm in width. The length of both polymer cladding parts was 20 mm. As the polymer clad 66, a copolymer of fluorinated methyl methacrylate and methyl methacrylate was used. Further, a diarylethane having a perfluorocyclopentene ring was used as a photochromic material added to the polymer clad 67. This material has excellent self-holding property of refractive index,
It is known to show a stability of 3 months or more at ° C.

FIG. 13 is a schematic perspective view showing the structure of a waveguide device in which the self-holding Mach-Zehnder interferometer of FIG. 12 is housed in a container having a quartz glass window and a fiber connector is attached. 68 is a Mach-Zehnder interferometer, 69 is a container, 70 is a quartz glass window, 71 is an upper lid, and 72 is an optical fiber with a connector. To operate this, an ultraviolet light source, a visible light source, and a bandpass filter for producing a photoreaction effect on the PC material of the polymer clad 67 are required. Laser diode not shown (wavelength 1.5
5 μm, output 1 mW) is connected to the connector of the optical fiber 72, and the connector of the optical fiber 72 on the opposite side is connected to the GaAs light receiving element (not shown). In this state, the light output is 0.
It was confirmed to be 9 mW. From this, it was found that the insertion loss of the device at 1.55 μm was 0.46 dB. Next, remove the upper lid 71 of the container 69,
An Xe-Hg lamp (100 W) was irradiated from the top through a quartz glass window 70 for 5 seconds through a 330 nm bandpass filter (UVD33S, made by Toshiba Glass; not shown). The irradiation intensity at this time is about 50 mW / cm ^2.
Met. Then, 1 minute after irradiation, the halogen lamp (150
W) was irradiated with light of 500 nm for 10 seconds using a bandpass filter of 500 nm (G-50, made by Toshiba Glass) and a sharp cut filter of 500 nm (Y-50). The light irradiation intensity at this time was 20 mW / cm ² . The output change of the laser beam having a wavelength of 1.55 μm at this time is shown in FIG. 14. The light output was 90 μW, which was 90% lower about 1 second after the start of ultraviolet irradiation, and the 90% response speed was about 1 second. I understood it. After that, the optical output drops to 10 μW within a few seconds, and the extinction ratio of the switch is 1
9.5 dB was confirmed. After 1 minute of ultraviolet irradiation, halogen lamp light was irradiated for 10 seconds. The time when the light output was 89% of the light output before the irradiation with the ultraviolet rays of 800 μW was about 4 seconds after the irradiation. The 90% recovery time was confirmed to be about 4 seconds. As a result, it was found that the phase shift of the waveguide arm containing the photochromic material of the Mach-Zehnder interferometer is π. Next, the Mach-Zehnder interferometer is exposed to two ultraviolet rays.
Irradiation was continued for 2 seconds to reduce the laser light output to 450 μW. The phase shift at this time is π / 2. In this state, the upper lid 11 was firmly closed so that the container 69 was not exposed to light, and the measurement was continued. Light output is 450 μW even after 50 hours
It was confirmed that the optical output was maintained with a fluctuation of ± 0.5 μW and 0.1% (FIG. 15). Furthermore, the fluctuation in light output was within 0.4% even after 3 months. In this way, it was confirmed that the phase of the waveguide can be kept constant for a long period of time.

A similar experiment was conducted by setting the laser wavelength to 1.3 μm, but the result equivalent to the case of 1.55 μm was obtained.

As is clear from these results, when used as a semi-fixed variable optical attenuator, stability and reliability are improved as compared with the prior art, especially power saving and simplification compared with elements using the TO effect. The metastasis was significantly improved.

[Embodiment 7] FIGS. 16A and 16B are views for explaining a seventh embodiment of the self-holding type optical waveguide device of the present invention. FIG. 16A is a top view and FIG. 3 is a sectional view taken along line ee of FIG. Reference numeral 73 is a directional coupler, 74 is a polymer clad to which a photochromic material is added at a fixed weight%, 75 is a polymer clad, 76 is a quartz waveguide core, 77 is a silica glass clad, and 78 is a silicon substrate. The size of the element is 80 mm in length and 4.5 mm in width. The length of both polymer cladding parts is 20 mm. A copolymer of fluorinated methyl methacrylate and methyl methacrylate was used as the polymer of the polymer clad. Further, diarylethene having a maleic anhydride group was used as the photochromic material. It is known that this photochromic material has excellent self-holding property of refractive index and has stability at 80 ° C. for 3 months or more.

This two-input, two-output optical switch was housed in a container with a quartz glass window as in Example 6 and a fiber with a connector was attached to form a switch element. This structure is shown in FIG.

In FIG. 17, 79 is a 2 × 2 optical switch,
Reference numeral 80 is a container, 81 is a quartz glass window, 82 is an upper lid, and 83 is an optical fiber with a connector. To make this work,
It is necessary to change the refractive index of the polymer clad 84 to which the photochromic material is added by the photoreaction effect. In order to operate in the same manner as in Example 6, an ultraviolet light source, a visible light source,
And a bandpass filter was prepared.

In order to operate this 2 × 2 switch, the output light of the laser diode (wavelength 1.55 μm, output 1 mW; not shown) is made incident on the incident port B of the 2 × 2 switch through the optical fiber 83. Next, as shown in FIG. 16, the optical fibers connected to the emission ports C and D are connected to two GaAs light receiving devices (not shown). In this state, it was confirmed that the light output of the emission port C was 800 μW. From this, the device's 1.55 μm
It was found that the insertion loss at 1 dB was 1 dB. The optical output at the output port D was 8 μW. Next, the upper lid 82 of the container 80 is removed, and a halogen lamp (150 W) (not shown) is attached from above to a 440 nm bandpass filter (V4).
Irradiation was carried out for 5 seconds through No. 4, Toshiba Glass; not shown). The irradiation intensity at this time was about 40 mW / cm ² . Then, 1 minute after irradiation, a visible laser diode (output: 20 mW) having a wavelength of 670 nm was spread by a beam expander to a width of 5 mm and a length of 20 mm, and the photochromic material-added polymer clad 74 was irradiated for 5 seconds. The light irradiation intensity at this time was 20 mW / cm ² .

FIG. 18 shows the change in the optical output of the emission ports C and D for the laser light having the wavelength of 1.55 μm. 44
Before irradiating 0 nm light, the light incident on the incident port B is emitted to the port C and is not emitted to the port D (cross switch state). Next, when light of 440 nm was applied through the quartz glass window 21, the output light of the output port C decreased by 90% or more after 1 second, and conversely the output light intensity of the output port D increased. After a few seconds, the light output of both emission light ports was reversed (bar switch state). This irradiation with 440 nm light was performed for 5 seconds. An output of 800 μW was observed at the emission port D, and an optical output of 8 μW was observed at the emission port C. As a result, a 90% response speed of 1 second and a crosstalk of 20 dB were achieved. 1 minute after irradiating 440 nm, wavelength 6
When a laser diode of 70 nm was irradiated, the state changed to a cross switch state within a few seconds. This 670 nm irradiation was performed for 5 seconds. The upper lid 82 was completely closed to maintain the cross switch state without power. When the light output of the emission port C was examined 50 hours after the light of 1.55 μm was passed, the variation was within 0.1%. When the change after 3 months was examined with light passing through, it was within 0.5%. As described above, it was confirmed that the cross state or the bar state can be kept constant for a long period of time with no power consumption and no adjustment.

Further, when the directional coupler 73 was a wavelength independent type (WINC), the wavelength of the laser was 1.3 μm, and the same experiment as in the case of 1.55 μm was conducted,
Similar results were obtained.

As is clear from this result, the semi-fixed 2 ×
When used as a two-optical switch, compared to conventional technology,
Significant improvements were seen in terms of stability and reliability, especially in terms of power saving and maintenance-free compared with the element using the TO effect.

[Embodiment 8] FIG. 19 is a view for explaining an eighth embodiment of the optical waveguide device of the present invention. 91 is a silicon substrate, 92 is a lower cladding, 93 is an upper cladding, 9
4 is a core, 95 and 96 are 3 dB directional couplers, 97
Is a polymer clad with a photochromic material, 98 is a polymer clad, 99 is a quartz glass plate, 100 is a light absorber-added polymer core, A is a light incident port, C is a light emitting port,
E is the Mach-Zehnder first arm, and F is the Mach-Zehnder second arm.

FIG. 20 is an enlarged sectional view taken along the line ff of FIG. 19 as seen in the direction of the arrow, and FIG. 21 is an enlarged sectional view taken along the line gg of FIG. FIG. 20 is a cross-sectional view of the center of the Mach-Zehnder arm portion, in which the polymer added with the photochromic material is used only in the first arm E, and its length is 5 mm. FIG. 21 shows the glass core portion as a polymer core 1 with a light absorber added.
A quartz glass plate 99 is used as the upper clad in the cross section of the part replaced with 00. The core portion 100 has a length of 5 mm. The total length of the element is 5
The width is 0 mm and the width is 5 mm.

In order to fabricate this, the lower clad 92 is first fabricated by the flame deposition method (FHD method) on the silicon substrate 91, then the layer to be the core portion is fabricated, and the reactive ion etching (RIE) is performed. ) In the apparatus, form the core shown by the broken line in FIG. Next, the upper clad 93 is formed in the portion excluding the polymer clads 97 and 98. Finally, the polymer core 100 portion is cut by a reactive ion etching (RIE) device as shown in the sectional view of FIG.

Refraction after drying with a polymer (a copolymer of fluorinated methyl methacrylate and methyl methacrylate) containing 10% by weight of a photochromic material (here, a diarylethene having a perfluorocyclopentene ring or maleic anhydride was used). The rate is 1.444 (wavelength 1.55
First, the polymer solution whose refractive index is adjusted so that
It was applied to arm E as a polymer solution. On the other hand, the refractive index after drying of the second arm F is 1.444 (wavelength 1.55 μm).
The polymer solution of the copolymer of fluoromethylmethacrylate and methylmethacrylate adjusted so as to be m) was applied. Further, a protective film 101 was formed on these polymer clads with a polymer or metal vapor deposition film.

Next, an ultraviolet absorber (maximum absorption wavelength 353 nm, trade name Tinuvin 326) and a visible light absorber (maximum absorption wavelength 550) were prepared in order to prepare a polymer core containing a light absorber.
nm, trade name Disverse First Violet 5
1% by weight of each of R) was mixed with a polymer (a copolymer of fluorinated methyl methacrylate and methyl methacrylate) to prepare a polymer solution. This was applied to a light absorber-containing polymer core 100 having a length of 5 mm. The refractive index of the polymer after drying is adjusted to 1.448 (wavelength 1.55 μm). After the solvent of the injected polymer solution is sufficiently evaporated, this portion is heated (80 ° C to 120 ° C).
The quartz glass plate 99 was pushed into the portion etched by RIE while the temperature was kept at .degree. The polymer softened by pressing lightly filled the core and the quartz glass plate 99 without any gap. Further, the epoxy adhesive 102 is applied to the gap between the quartz glass plate 99 and the upper clad 93, and a polymer solution, which is the same material as the polymer clad 98, is applied to a slight gap in the opposite light transmission direction. . An optical remote control type self-maintaining variable attenuator was manufactured by the above procedure.

To operate this, it is possible to introduce an optical signal from the light incident port A through an optical fiber and irradiate the control light from the upper surface of the element to change the optical intensity of the optical signal. On the other hand, the control light can be superposed on the signal light and incident from the optical fiber, and the amount of attenuation can be adjusted by remote control. The following light sources were used for remote control. Mercury xenon lamp (20
0 W, 1600 mW / cm ² ) irradiation light was passed through a 365 nm band-pass filter (band width 10 nm) to make it monochromatic, and then was directly incident on a quartz single mode fiber for optical communication with a lens collimator system and a xenon lamp. (200 W) irradiation light is passed through a bandpass filter (bandwidth 50 nm) of 550 nm to be monochromatic,
Similarly, a lens collimator system was used which was directly incident on a silica single mode fiber for optical communication. These two
Approximately 1k after combining two light sources into one optical fiber
m transmission. A light output of 0.9 mW for ultraviolet light and 0.6 mW for visible light was obtained at the end of the fiber. This optical fiber can transmit signal light together with control light.

The light intensity of 1.55 μm at the entrance port A is 1000 μW, and the light output from the exit port C is 90
It was 0 μW (insertion loss 0.46 dB). Next, when the irradiation light of the mercury-xenon lamp was irradiated with the shutter opened for 10 seconds, the light output was 9 μW and the light was not dimmed any more. After holding for 10 minutes in the dark state, the irradiation light of the xenon lamp was similarly irradiated for 10 seconds,
This time, conversely, the optical output of the emission port C became 900 μW. Also, when the irradiation light from the mercury-xenon lamp was irradiated with the shutter opened for 4 seconds, the light output immediately increased to 4
It became 00 μW, and this state was kept stable in the dark state for a long time (more than two months). In this state, the visible light and the ultraviolet light are alternately or continuously irradiated, and by changing the irradiation light amount, an arbitrary light attenuation amount (variable attenuation amount range 0 to 20 d) is obtained.
B) could be obtained. Once set by remote control, the attenuation showed long-term stability in the dark.

Control light guided (356 nm, 550 nm)
(nm) is emitted from the emission port C, which is not preferable for optical signal processing. For this purpose, a light absorber-added polymer core portion 100 that absorbs ultraviolet light and visible light was placed immediately before the emission port. The attenuation of ultraviolet light was 70 dB and the attenuation of visible light was 83 dB. On the other hand, in the communication wavelength band, the insertion loss was within 0.1 dB. By configuring the filter just before the light emission port in this way, it is possible to eliminate the adverse effects of the control light on the optical signal detection system and at the same time remove the instability of the element operation due to the incidence of ultraviolet light and visible light from the emission port. It was As a result, a self-maintaining variable optical attenuator (variable attenuation amount range: 0 to 20 dB, insertion loss:
0.46 dB) was achieved. Moreover, it was found that 1 km optical remote control using a silica optical fiber is possible.

Further, even in the heat cycle test (cycle time of 1 hour) in which the ambient temperature was changed from -20 ° C to 80 ° C, the fluctuation of the light output under an arbitrary attenuation amount was within 0.1% after 500 cycles or more. And showed good stability.

[Embodiment 9] FIG. 22 is a view for explaining the ninth embodiment of the optical waveguide device of the present invention, in which 111 is a silicon substrate, 112 is a lower cladding, 113 is an upper cladding, 114 is a core, 115 and 116 are 3 dB directional couplers, 117 is a photochromic material-added polymer clad, 118 is a polymer clad, and 119 is a quartz glass plate.
Reference numeral 120 is a light absorbent-added polymer core, A and B are light entrance ports, C and D are light exit ports, E is a Mach-Zehnder first arm, and F is a Mach-Zehnder second arm. The total length of the device is 50 mm and the width is 5 mm.

In order to fabricate this, the lower clad 112 is first fabricated on the silicon substrate 111 by the flame deposition method (FHD method), then the layer to be the core portion is fabricated, and the reactive ion etching (RIE) is performed. 22.) In the apparatus, form the core shown by the broken line in FIG. Next, polymer clad 117
The upper clad 113 is formed in a portion excluding and 118. Finally, the polymer core 120 portion is cut into a reactive ion etching (RIE) apparatus like the polymer core 100 in the eighth embodiment (see FIG. 21).

Refractive index after drying with a polymer (a copolymer of fluorinated methylmethacrylate and methylmethacrylate) containing 10% by weight of a photochromic material (here, diarylethene having a perfluorocyclopentene ring or maleic anhydride) was added. Is 1.444 (wavelength 1.
The polymer solution whose refractive index was adjusted to 55 μm) was applied to the first arm E as a polymer solution. Meanwhile, the second
The arm F has a refractive index of 1.444 (wavelength 1.5 after drying).
A polymer solution of a copolymer of fluorinated methyl methacrylate and methyl methacrylate adjusted to have a thickness of 5 μm was applied. Further, a protective film of a polymer or a metal vapor deposition film was formed on these.

Next, an ultraviolet absorber (maximum absorption wavelength 353
nm, trade name Tinuvin 326) and a visible light absorber (maximum absorption wavelength 550 nm, trade name Disverse Fast Violet 5R), each of which is mixed at 1% by weight with a polymer (a copolymer of fluorinated methyl methacrylate and methyl methacrylate). This was used as a polymer solution containing a light absorber. This is a polymer core portion 12 with a length of 5 mm
Applied to 0. The refractive index of the polymer after drying is 1.448.
The wavelength is adjusted to 1.55 μm.

After the solvent of the injected polymer solution was sufficiently evaporated, the quartz glass plate 119 was fitted while heating this portion (80 ° C. to 120 ° C.). The polymer softened by pressing lightly was filled between the core portion and the quartz glass plate 119 without any gap. Furthermore, an epoxy adhesive was applied to the gap between the quartz glass plate 119 and the upper clad 113, and a polymer solution (however, the same as that used to produce the polymer clad 118) was applied to a slight gap in the light transmitting direction. .

In order to operate this, there are a method of irradiating control light from the upper surface of the element for switching and a method of performing switching by optical remote control by an optical fiber described below.

As the light source for remote control, the irradiation light of a mercury xenon lamp (200 W, 1600 mW / cm ² ) equipped with a 365 nm bandpass filter was directly incident on a silica single mode fiber for optical communication by a lens collimator system. The irradiation light of a xenon lamp (200 W, 550 nm band-pass filter attached) was made to directly enter the optical fiber in the same manner. These optical fibers were put together into one, and the length was set to 1 km, which was connected to the incident port B of the device. The ultraviolet light intensity at the incident port was 0.9 mW, and the visible light intensity was 0.6 mW.

One single-mode fiber for signal light was connected to the entrance port A, and single-mode fibers were connected to the exit ports C and D, respectively. Light from a laser diode (wavelength 1.55 μm, output 1 mW) was made incident on the incident port A, and the optical fibers at the emission ports C and D were respectively connected to two GaAs light receiving devices. The light output from the emission port C was 900 μW, and the light output from the emission port D was 10 μW. Next, when the irradiation light of the mercury xenon lamp was opened for 10 seconds and the light was irradiated from the incident port B through the light control fiber, the light output of the emission port D immediately became 900 μW and the emission port C
Optical output of 10 μW. When this state was maintained for 10 minutes, irradiation light was similarly irradiated for 10 seconds with a xenon lamp.
μW, and the optical output of the emission port D became 10 μW. Control light guided to control the refractive index (356n
(550 nm) from the output ports C and D is not preferable for optical signal processing. For this purpose, the light absorbent-added polymer core portion 120 is installed immediately before the emission ports C and D so as to absorb the ultraviolet light and the visible light and allow only the signal light to pass therethrough. The attenuation of ultraviolet light was 70 dB and the attenuation of visible light was 83 dB. On the other hand, in the communication wavelength band, the insertion loss was at most 0.1 dB. By constructing the filters on the side of the light emission ports C and D as described above, it is possible to eliminate the adverse effect on the optical signal and at the same time remove the instability of the device operation due to the incidence of ultraviolet light and visible light from the emission light port. . As a result, this self-holding optical switch has high reliability and an extinction ratio of −
It was found that the switch characteristics were 19.5 dB and insertion loss: 0.58 dB. Moreover, it has been found that it is possible to control a remote optical switch of 1 km using a silica optical fiber.

Further, even if the optical switch was left in a dark place for one year or more, the fluctuation of the optical output of 900 μW was within 0.1%, which showed good stability. Also, in a heat cycle test (cycle time 1 hour) in which the light temperature was changed from -20 ° C to 80 ° C, the light output fluctuation rate was within 0.1% and good stability was shown after 500 cycles or more.

[0109]

As described above, according to the present invention, the phase of the light propagating through the core can be easily set, and moreover, the phase can be set easily because it can be maintained stable, without power consumption, and without control for a long period of time. It is possible to provide a semi-fixed phase adjuster or a self-maintaining optical waveguide device having a long-term phase maintaining function.

For example, an optical attenuator capable of self-holding operation,
Optical switch capable of self-holding operation, high-precision waveguide phase adjuster, phase self-holding ring resonator, Mach-Zehnder interferometer with ring resonator, multi-channel frequency selective switch, multi-channel optical multiplexer / demultiplexer, phase interference effect Type transversal filters, tunable optical couplers and the like. Among these, the waveguide phase high-precision adjuster can be used for a final phase adjuster before factory shipment of an optical integrated circuit.
Further, an N × N optical switch typified by a 2 × 2 optical switch can be used as a self-holding operation optical switch for switching the line of an optical fiber concentrator before entering an optical switch and switching the home wiring of an optical subscriber. It is possible to switch lines without dynamic operation, improving reliability and simplicity.

Further, since the control of the element can be easily performed on the spot by using a strobe etc., and also by the optical transmission using the single mode fiber, the element can be remotely controlled only by the light. is there. Therefore, it can be used as an optical subscriber system optical transmission changeover switch, and can be applied to an optical LAN.

As described above, the present invention gives a new development to the phase control of the conventional optical waveguide device, and greatly contributes to the development of the optical communication industry.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment of an optical waveguide device of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line aa in FIG.

FIG. 3 is an enlarged cross-sectional view taken along line bb in FIG.

FIG. 4 is a diagram showing a switching characteristic of an optical switch which is the optical waveguide device shown in FIG.

FIG. 5 is a perspective view showing a configuration of a second embodiment of the optical waveguide device of the present invention.

FIG. 6 is a perspective view showing the configuration of a third embodiment of the optical waveguide device of the present invention.

FIG. 7 is an enlarged cross-sectional view taken along line cc in FIG.

FIG. 8 is an enlarged cross-sectional view taken along line d-d in FIG.

FIG. 9 is a perspective view showing a configuration of a fourth embodiment of the optical waveguide device of the present invention.

FIG. 10 is a perspective view showing the configuration of a fifth embodiment of the optical waveguide device of the present invention.

11 is a perspective view with a part omitted showing the configuration of a modification of the groove-shaped core in the optical waveguide device shown in FIG.

FIG. 12 is a schematic perspective view showing a configuration of a self-holding Y-branch Mach-Zehnder waveguide device which is a sixth embodiment of the optical waveguide device of the present invention.

13 is a schematic perspective view showing a configuration of a semi-fixed optical attenuator in which the waveguide element shown in FIG. 12 is housed in a container.

14 is a characteristic diagram showing an output change curve of laser light having a wavelength of 1.55 μm, which is changed by irradiation of light in a specific wavelength range on the semi-fixed optical attenuator shown in FIG.

15 is a characteristic diagram showing output stability in a state where the light output is halved after the change in the light output in FIG.

FIG. 16 is a diagram showing a configuration of a 2 × 2 optical switch that is a seventh embodiment of the self-holding type optical waveguide device of the present invention,
(A) is a top view, (b) is sectional drawing which follows the ee line in (a).

FIG. 17 is a schematic perspective view showing a configuration of a semi-fixed 2 × 2 optical switch in which the 2 × 2 optical switch shown in FIG. 16 is housed in a housing container.

FIG. 18 is a characteristic diagram showing a crossbar switch characteristic curve changed by light irradiation with respect to the semi-fixed 2 × 2 optical switch shown in FIG. 17;

FIG. 19 is a perspective view showing the configuration of an eighth embodiment of the optical waveguide device of the present invention.

20 is an enlarged sectional view taken along line ff in FIG.

FIG. 21 is an enlarged cross-sectional view taken along the line gg in FIG.

FIG. 22 is a perspective view showing the configuration of a ninth embodiment of the optical waveguide device of the present invention.

[Explanation of symbols]

1, 11, 41 Silicon substrate 2, 12, 13, 42, 43 Clad 3, 14, 44 Core 4, 5, 15, 16, 23, 26, 33, 36, 45,
46 3dB directional coupler 6,17,22,47,50 Quartz glass plate 7,18,24,34,48 Polymer core with photochromic material added 8,25,35 Polymer core 9,49,52 High Molecule clad 10 Adhesive 21 Quartz glass substrate 27, 37, 51 Polymer core with light absorber 31 Plastic substrate 32 Plastic plate 61 Silicon substrate 62 Lower quartz glass clad produced by flame deposition method 63 Produced by the same method Core (9 μm × 9 μm, Δn
= 0.3%) 64 Upper glass clad 65 Y branch core 66 Polymer clad 67 Polymer clad with 10% by weight of PC material 68 Mach-Zehnder interferometer 69 Container 70 Quartz glass window 71 Top lid 72 Optical fiber with connector 73 Directionality Coupler 74 Polymer clad to which a certain amount of PC material is added 75 Polymer clad 76 Quartz waveguide core 77 Quartz glass clad 78 Silicon substrate 79 2 × 2 optical switch 80 Container 81 Quartz glass window 82 Top lid 83 Optical fiber with connector 91 Silicon substrate 92 Lower clad 93 Upper clad 94 Core 95, 96 3 dB directional coupler 97 Polymer clad with photochromic material 98 Polymer clad 99 Quartz glass plate 100 Polymer core with light absorber 101 Protective film 102 Contact Adhesive 111 Silicon substrate 112 Lower clad 113 Upper clad 114 Core 115,116 3dB directional coupler 117 Polymer clad 118 with photochromic material 118 Polymer clad 119 Quartz glass plate 120 Polymer core A with light absorber A , B, I, J, O, P, U, V Light incident port C, D, K, L, Q, R, W, X Light emission port E, M, S Mach-Zehnder first arm F, N, T Mach-Zender 2nd arm G, Z Lower arm H, Y Upper arm

Claims (4)

[Claims] 1. An optical waveguide device comprising at least a core and a clad, wherein at least a part of the core contains an organic compound capable of changing the refractive index of the core only by irradiation with light in a specific wavelength range. Characteristic optical waveguide device. 2. An optical waveguide device comprising at least a core and a clad, wherein at least a part of the clad is
An optical waveguide device comprising an organic compound capable of changing the refractive index of the clad only by irradiation with light in a specific wavelength range. 3. A method for controlling an optical waveguide element comprising at least a core and a clad, at least one of the core and the clad including an organic compound capable of changing the refractive index of the one only by irradiation with light in a specific wavelength range. By irradiating the light of the specific wavelength range from one end of the core, and changing the refractive index of the core or the clad by the irradiation,
A method of controlling an optical waveguide device, which comprises controlling a phase of light propagating through the core. 4. A method of controlling an optical waveguide element comprising at least a core and a clad, at least one of the core and the clad including an organic compound capable of changing the refractive index of the one only by irradiation with light in a specific wavelength range. And irradiating the light in the specific wavelength range from a direction orthogonal to the optical waveguide of the optical waveguide element, changing the refractive index of the core or the clad by the irradiation, and controlling the phase of the light propagating in the core. A method for controlling an optical waveguide device, the method comprising: