JPH05173038A - Connecting mechanism between optical waveguide and optical fiber - Google Patents

Abstract

PURPOSE:To provide a connecting mechanism between an optical waveguide and an optical fiber which can smoothly transmit light by reducing a complicated aligning work and suppressing a connection loss. CONSTITUTION:A core 40 on the abutting part of the optical waveguide 4 is recessed so as to have a cross section with an approximate recessed shape to execute aligning work. On the other hand, a core 100 on the abutting part of the optical fiber 10 is protruded so as to have a cross section with an approximate recessed shape to execute the centering work. After abutting both the cores 40, 100 with pressure from both the ends, the abutting part of a positioned coupling holder is welded by YAG without executing vertically aligning work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for connecting an optical waveguide and an optical fiber, and more particularly, to an improvement in an abutting portion of an optical waveguide and an optical fiber which are butted to each other.

[0002]

2. Description of the Related Art In the conventional connection between an optical waveguide and an optical fiber, an optical waveguide provided in a coupling optical waveguide holder and an optical fiber provided in a coupling optical fiber holder are arranged in a line and are joined and abutted. This is done by aligning the core at the tip of the optical waveguide and the core at the tip of the optical fiber in the vertical and horizontal directions, and then welding the abutting portions of the abutting coupling holders. However,
In order to smoothly transmit light while suppressing the connection loss, it is necessary to perform centering work for centering the core at the tip of the optical waveguide and the core at the tip of the optical fiber in the vertical and horizontal directions.

[0003]

The conventional optical waveguide and optical fiber are connected as described above, and in order to smoothly transmit light while suppressing connection loss, the core of the optical waveguide tip and the optical fiber tip are Since the complicated centering work for centering the core in the vertical and horizontal directions is indispensable, a great deal of labor and a long time have been required for the centering work.

The present invention has been made in view of the above circumstances, and provides a connecting mechanism for an optical waveguide and an optical fiber, which can reduce the complicated alignment work and suppress the connection loss to smoothly transmit light. It is an object.

[0005]

In the present invention, in order to achieve the above-mentioned object, the core at the abutting portion of either one of the optical waveguide and the optical fiber connected to each other is provided with a concave shape in cross section. It is characterized in that the core at the other butting portion is provided so as to project in a substantially convex shape in cross section, and the optical waveguide and the optical fiber are butted and aligned by the concave and convex fitting of the core.

[0006]

According to the present invention, a core having a concave shape or a convex shape exposed at the abutting portion of the optical waveguide and a core having a convex shape or a concave shape exposed at the abutting portion of the optical fiber are pressed against each other at both ends and abutted. Even if the core alignment work in one direction is omitted, if the abutted cores are fitted in concavo-convex,
The core alignment function can significantly reduce connection loss, reduce complicated alignment work, and allow light to be transmitted smoothly.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to an embodiment shown in FIGS. 1 to 6. The optical waveguide and optical fiber connection mechanism according to the present invention has an optical waveguide substrate 3 built-in as shown in FIG. A single coupling optical waveguide holder 1 and a plurality of coupling optical fiber holders 6 each including a tape-shaped optical fiber 9;
6A and 6A are arranged in a line and are connected and abutted. Then, after the core at the tip of the optical waveguide and the core at the tip of the optical fiber are aligned in the left-right direction, the abutting portions of the abutting coupling holders 1, 6 and 6A are sequentially YAG welded.

As shown in FIG. 2, the coupling optical waveguide holder 1 is composed of a metal 2 having an electric circuit (not shown) housed in a recessed hole at the center of the upper surface thereof, and quartz glass or the like. An optical waveguide substrate 3 which is horizontally installed by an adhesive, and a plurality of optical waveguide substrates 3 which are embedded side by side in a straight line or a curved line in the longitudinal direction of the inside of the optical waveguide substrate 3 (in FIG.
Main) optical waveguide 4 and a lid metal 5 which is attached to the upper surface of the metal 2 to cover the optical waveguide substrate 3, and is not shown.
The electric circuit and the electrodes (not shown) of the optical waveguide substrate 3 are electrically connected.

Further, the plurality of coupling optical fiber holders 6 and 6 for sandwiching the coupling optical waveguide holder 1 from both ends.
As shown in FIG. 3, A is a silicon plate 8 placed on the tip of the upper surface of the metal 7 and having a plurality of V grooves 8a (see FIG. 6) arranged side by side on the upper surface, and a silicon plate 8 inserted into the rear end of the upper surface of the metal 7. The tape-shaped optical fiber 9 directed toward the silicon plate 8 and a plurality of Vs extending from the tip of the tape-shaped optical fiber 9 and branched.
A plurality of optical fibers 10 arranged in the groove 8a in the same direction,
It is provided with a pressing plate 11 which is superposed on the silicon plate 8 and fixes a plurality of optical fibers 10, and a lid metal 12 which is attached to the upper surface of the metal 7 and covers the optical fibers 10.

On the other hand, as shown in FIGS. 4 and 5, the optical waveguide 4 is provided with a core 40 having a large refractive index and a clad 41 having a refractive index smaller than that of the core 40, and the core 40 at the tip, which is a butt portion. Is recessed in a substantially concave cross section so as to perform the centering action. That is, at the tip of the optical waveguide 4, the surface other than the core 40 (the surface of the clad 41) is masked by the adhesion of tungsten silicite, and the core 40 becomes CF.
After being etched by the gas of No. ₄ , the attached mask is peeled off so that the core 40 is exposed to have a substantially concave cross section in the longitudinal direction. As a result, in cooperation with the core 100 at the tip of the optical fiber, which will be described later, the concave-convex fitting causes the centering action.

On the other hand, the optical fiber 10 is shown in FIGS.
, The core 100 having a large refractive index and the core 1
And a clad 101 having a refractive index smaller than that of 00, and the tip of the abutting portion is 50 μm from the tip of the V groove 8a.
The core 100 at the distal end is projected and supported in a freely movable state, and the core 100 at the tip is projected in a substantially convex shape in cross section so as to perform an aligning action. That is, at the tip of the optical fiber 10, the surface of the core 100 is masked by the adhesion of tungsten silicite, and the surface of the clad 101 other than the core 100 is C.
After etching with the gas of F ₄ , the attached mask is peeled off so that the core 100 is exposed to have a substantially convex cross-section in the longitudinal direction. As a result, in cooperation with the core 40 at the tip of the optical waveguide described above, the centering action is performed by the concavo-convex fitting.

Accordingly, while suppressing the connection loss, the coupling optical waveguide holder 1 and the plurality of coupling optical fiber holders 6
In order to connect with 6A, first, the coupling optical waveguide holder 1 having the optical waveguide substrate 3 and the plurality of coupling optical fiber holders 6 and 6A having the tape-shaped optical fibers 9 are arranged as shown in FIG. Arrange in a line. Next, as shown in FIG. 4, the core 40 at the tip of the optical waveguide having a substantially concave cross section and the core 100 at the tip of the optical fiber having a substantially convex cross section are opposed to each other, and the plurality of coupling holders 1, 6 ,. 6A is connected in the longitudinal direction to align the cores 40 and 100 in the left-right direction. Then, after positioning the plurality of coupling holders 1, 6 and 6A, the plurality of coupling holders-1 and 6 abutted against each other.
-The 6A butt joints may be sequentially YAG welded.

According to the above construction, the holders for coupling 1, 6 and 6A which are pressed from both ends are butted against each other and the core 40 and 1
00 is aligned in the left-right direction, and holders for coupling-1, 6.6A
By positioning, the core 40/100 can be aligned with high accuracy of ± 2 μm by the concave-convex aligning action of the tip core 40/100 without complicated centering work in the vertical direction. It is possible to significantly reduce the loss to 0.2 dB or less.

In the above embodiment, the core 40 of the optical waveguide 4 is used.
Shows a cross section having a substantially concave shape and the core 100 of the optical fiber 10 having a substantially convex shape in cross section. The core 40 of the optical waveguide 4 has a substantially convex shape in cross section, and the core 100 of the optical fiber 10 has a cross section. It goes without saying that they may be formed in a substantially concave shape.

[0015]

As described above, according to the present invention, the core that performs the aligning action of the concave section in the abutting portion of the optical waveguide and the aligning action of the convex section in the abutting portion of the optical fiber are performed. After press-fitting the core from both ends and abutting it, YAG welding of the abutting portions of the plurality of positioned holders for coupling is performed sequentially, and the core can be adjusted to ± 2 μm without complicated centering work in the vertical direction. There is a remarkable effect that the centering can be performed with high accuracy. Then, this has a remarkable effect that the connection loss can be greatly suppressed to 0.2 dB or less, the complicated alignment work can be significantly reduced, and the light transmission can be smoothly performed.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing a connection mechanism between an optical waveguide and an optical fiber to which an embodiment of the present invention can be applied.

FIG. 2 is an enlarged perspective view showing a coupling optical waveguide holder to which an embodiment of the present invention can be applied.

FIG. 3 is an enlarged perspective view showing a coupling optical fiber holder to which an embodiment of the present invention can be applied.

FIG. 4 is an enlarged explanatory view of a main part showing an embodiment of a connection mechanism between an optical waveguide and an optical fiber according to the present invention.

FIG. 5 is an enlarged perspective view showing the tip of the optical waveguide of the coupling optical waveguide holder to which the embodiment of the present invention can be applied.

FIG. 6 is an enlarged perspective view showing an optical fiber tip of a coupling optical fiber holder to which an embodiment of the present invention can be applied.

[Explanation of symbols]

1 ... Optical waveguide holder for coupling, 3 ... Optical waveguide substrate, 4 ...
Optical waveguide, 6 ・ 6A ... Coupling optical fiber holder, 9 ...
Tape-shaped optical fiber, 10 ... Optical fiber, 40 ... Optical waveguide core, 100 ... Optical fiber core

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Saito 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Hiroshi Suganuma 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa Electric Industry Co., Ltd. Yokohama Works

Claims (1)

[Claims] 1. A core at an abutting portion of one of an optical waveguide and an optical fiber connected to each other is provided with a concave shape in cross section, and a core at another abutting portion is provided with a convex shape in cross section. A connection mechanism between an optical waveguide and an optical fiber, characterized in that the optical waveguide and the optical fiber are butted against each other by fitting the concave and convex portions of the core.