JPS5913453B2 - Method for manufacturing multicomponent glass fiber matrix - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a multicomponent glass fiber matrix.

Multi-component glass fiber is made by adding alkali metal oxides such as Na2O and 2O to SiO2, and has advantages such as being able to be melt-spun at low temperatures and having little Rayleigh scattering.

By the way, in order to manufacture such a multi-component glass fiber, the vapor pressure of the alkali metal halide at room temperature 5 is extremely low and it is impossible to vaporize it, so so-called vapor phase chemical precipitation is required. This could not be done using the CVD method. For this reason, conventional multi-component glass fiber production has had no choice but to rely on a melting method using a crucible. 0 However, this method requires a process of ultra-purifying the individual raw materials, mixing these raw materials, and then melting them.
The process was complicated and the operation was troublesome.

In particular, when using powdered materials such as NaNO3, KNO3, L1N03, etc.5, it is not only troublesome to mix them uniformly, but also they need to be melted for a long time in a crucible, etc., so they tend to be contaminated with impurities. Therefore, it was difficult to reliably form a low-loss optical fiber. The present invention has been made in view of the above circumstances, and its object is to create a multi-component glass fiber matrix that has advantages such as a simple process and the ability to reliably form a low-loss optical fiber. The objective is to provide a method for manufacturing materials.

Its characteristics are SiCl4, GeCl4, POCl3, B
Supplying a glass main raw material such as Br3 and a mist consisting of an aqueous solution of '5 metal salt into a flame to form a multi-component glass fine powder, and depositing this on the outer periphery or tip of a rod-shaped base material. It is in. Hereinafter, the present invention will be explained in detail with reference to the drawings. First, SlCl4, GeCl4, P0Cl3,
Main glass raw materials such as BBr310 are converted into H2, O2, A, H
It is supplied into the multi-tube burner 9 together with various gases such as e and N2, and gas phase reactions such as flame hydrolysis and thermal oxidation are carried out within the flame 9'. On the other hand, nitrates, carbonates, sulfates, and halogenated metals such as NaNO3, KNO3, LlNO3, etc.
An aqueous solution of ion exchange resin, etc., is introduced from introduction pipe 1 into ion exchange resin 2.
After passing through a column 3 packed with ion exchange resin 5 for purification, it is further purified through a column 6 packed with the same ion exchange resin 5 via a conduit 4 to prepare an ultra-highly purified aqueous alkali metal salt solution. do. After that, this aqueous solution is led out from the column 6 and introduced into the fog generator 8 through the conduit 7, and the obtained Na
A mist or particulate matter such as NO3, KNO3, LlNO3 is injected into the flame 9' from the injection port 12. The fog generator 8 may be one that uses ultrasonic waves or a normal fog generator that uses high-purity argon gas or the like.

Thus obtained SlO2, GeO2, B2O3, p2
Multi-component medium glass fine particles consisting of O5 and oxides of alkali metals such as Na2O, K2O, Li2O, etc. are adhered and deposited on the lower end of the rod-shaped base material 10, and while the rod-shaped base material 10 is pulled up, the medium glass fine particles are pivoted. A porous preform 11 of multi-component glass is formed by growing the glass in the same direction.

Next, the porous preform of multi-component glass formed as described above is heated in a zone melt or a heating furnace to form transparent glass.

Thereafter, the transparent glass is subjected to a predetermined treatment to form a multi-component glass optical fiber. For example, when transparent glass serving as the core and transparent glass serving as the cladding are formed separately, an optical fiber can be formed by melting them in a platinum crucible or the like and then drawing them out. Furthermore, after forming a porous preform as a core, a porous preform as a cladding is formed on top of this to form an integrated porous preform, and when this is made into transparent glass,
Optical fibers can also be formed by drawing to form a drawn rod and spinning this drawn rod. A variety of other conventional methods can also be used to form the stave or square distribution optical fiber. Further, the multi-component glass fine particles may be deposited on the base material not only on the tip but also on the outer periphery.

As explained above, in the present invention, SiCl4,G
A porous preform of multi-component glass is formed by supplying a mist consisting of glass main raw materials such as eCl4, POCl3, BBr3 and an aqueous metal salt solution into a flame, and then a multi-component preform is formed from this porous preform. It forms an optical fiber made of glass. Therefore, by supplying the metal salt aqueous solution into the flame as a mist, a vapor phase chemical deposition method (CVD method) can be adopted, which simplifies the process and efficiently deposits these metal oxides into the glass. Can be added at high concentrations. In addition, since the metal salt is handled in the form of an aqueous solution, it is possible to use advanced purification methods such as ion exchange and solvent extraction methods, making it easy to achieve a high degree of purification.Moreover, it is made into an oxide by vapor phase chemical precipitation. , the amount of impurities mixed in is extremely low, and when used as an optical fiber, a product with low transmission loss can be obtained. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 In the apparatus shown in FIG. 1, a 30% NaNO3 aqueous solution is introduced into a column 3 filled with an ion exchange resin 2 through an inlet pipe 1.
After passing through a conduit 4, the aqueous solution was purified by passing through a column 6 filled with a similar ion exchange resin 5, and the purified aqueous solution was introduced through a conduit 7 into a fog generator 8 using ultrasonic waves.

On the other hand, in the multi-tube burner 9, SiCl42OOc, G
eCl4lOOcq? , BBr35Occ/min, POC
132Occ/I3- was supplied, and 50cc/min of a mist formed by applying ultrasonic waves of 50 W and 80 KHz to the purified NaNO3 aqueous solution in the fog generator 8 using ultrasonic waves was injected into the injection port. 12 into the flame q to form a core of multi-component glass at the lower end of the rod-shaped base material 10. A porous preform 11 was formed.

Next, in the same manner as above, SiCl42OOCq, G
eCl45Occ/min, POCl to BBr35Occ/
A porous preform 11 of multi-component glass serving as a cladding was formed using 40 CC/min of a 30% NaNO3 aqueous solution to 32 Occ/min.

Next, the porous preform serving as the core and the porous preform serving as the cladding were respectively heated in a heating furnace to become transparent vitrification, thereby forming two types of transparent glasses.

Thereafter, a transparent glass core was placed inside a platinum double crucible, while a transparent glass cladding was placed outside of the crucible, and the crucible was pulled out at a temperature of 800°C and a drawing speed of 20 an/min to separate the core and cladding. A multi-component glass optical fiber was formed. The obtained optical fiber has a step-type refractive index distribution as shown in Figure 2, and has a wavelength of 0.83.
The transmission loss in μm was 11 dB/Km. Example 2
An optical fiber was formed in the same manner as in Example 1, except that a 32% KNO3 aqueous solution was used instead of the NaN03 aqueous solution.

The obtained optical fiber had a step-type refractive index distribution like the optical fiber of Example 1, and the transmission loss at a wavelength of 0.83 μm was 10 dB/Km. Example 3 In the apparatus shown in FIG. 3, a mixed solution of equal amounts of 30% NaNO3 aqueous solution and 30% KNO3 aqueous solution was introduced into pipe 1.
The mixture was introduced into a column 2 filled with ion exchange resin for purification, and then introduced into an atomizer 8 using argon gas.

On the other hand, SiCl4lOOCc/min, POCl35Occ/min, and 023000 CC/min are fed into the multi-tube burner 9 and burned, and the purified mixed solution is atomized by the atomizer 8 to produce a mist of 0.39/min. A porous preform 11 of multi-component glass was formed on the outer periphery of the rod-shaped substrate 10 by rotating the rod-shaped substrate 10 while injecting the flame q from the injection port 12 and moving it back and forth in the direction of the rotation axis.

The rotational speed of the triangular base material 10 was 20 rpm, and the reciprocating speed was 300 m71/min. During this process, the amount of SlCl4 supplied to the multi-tube burner 9 was increased by 50 cc/min from 100 cc/min to 200 cc/min for each reciprocating movement of the rod-shaped base material 10 in order to create a graded by continuously changing the refractive index. I let it happen. The obtained BRIFORM 11 was transparently vitrified at a temperature of about 1400°C in a carbon resistance furnace, and then the rod-shaped base material 10 was hollowed out and further heated to make it solid, and then melt-spun from the tip to form a multi-component system. A glass graded index type optical fiber was obtained.

．． The refractive index distribution of this material shows a square distribution as shown in Figure 4, and the transmission loss at a wavelength of 0.83 μm is 12 dB/Km.
It was hot. Comparative Example An example using the conventional double crucible method is shown.

First, in order to obtain glass for the core, SiO265wt%,
GeO2lOwt%, B2O3lOwt%, NaCO3
15 wt% was put into a platinum crucible, heated to about 1400°C to make it into a molten state, the temperature was further raised, and the mixture was stirred using a stirrer. The molten glass homogenized by this stirring was poured into a mold, solidified, and then taken out to form a multicomponent glass block for a core. On the other hand, in a similar manner, SlO2
7Owt%, B2O32Owt%, NaCO3lOwt
%, we have developed a multi-component glass block for cladding. Next, the glass block for the core was cut and polished to a shape that would fit snugly into the central crucible of the double platinum crucible. In addition, after cutting the glass proc for the cladding into multiple pieces,
Each was polished to fill the inside of the outer crucible. The double crucible containing the glass for the core and the cladding was heated to about 1000° C. to melt it, and was pulled out from the opening at the bottom of the double crucible to obtain a multicomponent glass fiber having a core diameter of 80 μm and an outer diameter of 150 μm. The transmission loss of the fiber made of multi-component glass thus obtained is at a wavelength of 0.83 μm.
It was 15dB/Km at

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of the apparatus used in Examples 1 and 2 of the present invention, Fig. 2 is a refractive index distribution diagram of the optical fibers obtained in Examples 1 and 2, and Fig. 3 4 is a schematic explanatory diagram of the apparatus used in Example 3, and FIG. 4 is a refractive index distribution diagram of the optical fiber obtained in Example 3. 8...Fog generator, 9...Multi-tube burner, 10...Rod-shaped base material, 11...Porous brifform, 12...・Injection port.

Claims (1)

[Claims] 1 When manufacturing a multi-component glass fiber base material, S
iCl_4, GeCl_4, POCl_3, BBr_3
A multi-component glass powder is formed by supplying a mist consisting of a main glass raw material such as and a metal salt aqueous solution into a flame to form a multi-component glass fine powder, which is deposited on a rod-shaped base material or at its tip. Manufacturing method of component-based glass fiber base material.