JPH0369524A - Production of functional glass - Google Patents

Abstract

PURPOSE:To uniformly disperse an additive in glass at the time of impregnating a porous glass base material with a soln. contg. the oxide additive and then heat treating the base material to produce the functional glass by impregnating the base material with the soln. while applying an ultrasonic wave. CONSTITUTION:The porous glass base material 1 is impregnated with the soln. 3 contg. one or plural oxide additives or a compd. capable of being converted to an oxide additive by heat treatment, and then heat-treated (quartz furnace core tube 6 and heater 7) to produce a functional glass contg. the oxide additive. In this method, the base material is impregnated with the soln. while applying an ultrasonic wave (oscillator 5). ErCl3.6H2O, NdCl3.6H2O, SnCl3.6H2O, PrCl3.6 H2O, TmCl3.6H2O, etc., are exemplified as the oxide additive. Methanol, ethanol, etc., are preferably used as the solvent for the oxide additive. The ultrasonic wave oscillation is carried out preferably at 45kHz and room temp. for about 30min to 1hr.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing functional glass that is applied to optical fiber lasers, optical direct amplifiers, etc. The present invention relates to a novel method for

[Conventional technology]

As a conventional technique, for example, as shown in Japanese Patent Publication No. 58-3980, a desired material is injected into a porous glass base material (hereinafter sometimes abbreviated as porous base material) obtained by a flame hydrolysis reaction. impregnating the impregnated porous material with a substance that contains an oxide additive or a compound that can be converted into the oxide additive by heat treatment and is chemically substantially inert to the porous matrix; There is a method of heat treating a matrix to obtain a glassy body containing at least a portion of the dispersed oxide additive.

As this oxide additive, if you select one that exhibits functionality based on absorption characteristics, fluorescence characteristics, etc. when added to glass, it is possible to create a glass that has functionality such as optical amplification, optical laser, attenuator, various sensing, etc. This method is attracting attention because it can be used in fields such as optical communication, optics, and measurement because it can produce objects with a shape of

[Problem to be solved by the invention]

However, in conventional methods of this type, the diffusion of the additive into the matrix was dependent only on the osmotic pressure of the solution to be impregnated into the porous matrix. It is difficult to uniformly disperse the material without causing aggregation within the base material, and this point was one of the issues to be solved. In particular, the smaller the pore volume of the porous base material, the more difficult it was to achieve uniform dispersion.

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an improved manufacturing method that can easily realize a functional glass in which oxide additives are very uniformly dispersed in the glass.

[Means to solve the problem]

The present invention provides a method for adding oxides by impregnating a porous glass base material with a solution containing one or more desired oxide additives or a compound that can be converted into the oxide additives by heat treatment, and then heat-treating the material. The above-mentioned problems are overcome by a method for producing functional glass, which is characterized by impregnating a porous base material with the solution while applying ultrasonic waves.

The present invention will be specifically described below with reference to the drawings.
The figure shows an example of the present invention in the order of steps. First, a separately manufactured porous glass base material 1 is converted into an oxide additive using an oxide additive or heat treatment in a solution bath 4. The sample is immersed in a solution 3 containing one or more of oxidizing compounds (hereinafter collectively referred to as oxide additives), and subjected to ultrasonic waves using an ultrasonic oscillator 5 [(section 81 in FIG. 1)].

The porous glass base material 2 impregnated with the oxide additive-containing solution as described above is then dried, and the solvent is removed by evaporation [(b1 part in Figure 1)].The oxide-impregnated base material 2 is Next, the functional quartz glass containing the oxide additive can be obtained by heat treatment to make it transparent in a heating furnace equipped with a quartz furnace core tube 6 and a heater 7.

[Effect]

As shown above, in the present invention, by applying ultrasonic waves when impregnating a porous base material with a solution containing additives,
Additives can be uniformly dispersed without causing any aggregation.

The porous glass matrix according to the present invention has a composition of S
The main component is i02, and if necessary, for example, GeO2 is added as a main component.
x, P2O3, F, AI! 20s or the like can be used.

The method for producing the porous glass base material is not particularly limited, but it can be produced using, for example, a flame hydrolysis reaction such as a VAD method or an OVD method.

Kaza density of the porous glass base material [St per unit volume]
Otsusu - defined in weight (g/cn?)] is 03
~1.5 g/cal, preferably 04-0.9 g/c
The reason for this is that if it is less than 0.3 g/cJ, it will easily collapse during immersion or drying, and 0.9 glc
This is because exceeding JI is disadvantageous in that the amount of impregnation decreases.

In the present invention, as the oxide additive, for example, HrC
fr6H20, NdCf5・6H20, 5nCj's・
6H20, PrClv6 Hz OSTmCes・6
H20 etc. can be used.

As a solvent for the oxide additive, alcohols such as methanol, ethanol, propanol, and water can be used, and methanol, ethanol, and the like are particularly preferred from the viewpoint of surface tension.

The concentration of the oxide additive in the solution is generally between 0001 and O
The amount is about 1 mol/l, but it may be set as appropriate depending on the required characteristics of the functional glass.

Examples of conditions for ultrasonic oscillation include, for example, 45 kllz and room temperature for about 30 minutes to 1 hour.

Drying of the porous matrix impregnated with the oxide additive-containing solution is
by various known techniques, e.g.
It can be dried by leaving it for about a day.

After drying, the impregnated base material is heated to a high temperature to make it transparent.
For example, in an atmosphere consisting of 1 or 1t and 02, 150
Examples of conditions include heating at 0 to 1600°C for 30 minutes.

During this clarification step, additives added in the form of compounds such as chlorides are converted into oxides. When these additives are added in an O8 atmosphere, they react as shown in the following formula, for example, and can be dissolved into the glass as oxides.

By doing as described above, a functional glass according to the present invention having an additive concentration of about 5000 ppm can be produced. The amount added can be changed depending on the concentration distribution and the time to saturate the solution.

〔Example〕

Example 1 Pure Si 02 porous matrix (8oIII
(Raw material 5iCe* 9
00 cc/min, Hg 281 /min, 0.30 A/min). The porous base material was heat treated at 1450° C. for 5 minutes in a field atmosphere. The pore volume of the porous base material after heat treatment was 60% of the total (43mlφx220+nm).

Separately, [irCI! *・6 H20-methanol solution (
The porous base material whose pore volume had been adjusted by the heat treatment was impregnated into the solution. In this state, the entire solution was subjected to ultrasonic waves of 45 kllz and left for 1 hour [Fig. 1(a)]. Next, the porous base material containing the 0r solution was pulled out and dried at room temperature to remove the solvent component (methanol) [FIG. 6(b)]. The E
The r-impregnated base material was then heat-treated at a heater temperature of 1650° C. and a descending rate of 2 mm/min. The atmosphere in the furnace at this time was set to lie 51 /min and 02Iff/min [FIG. 4(C)]. The transparent vitrified base material had a pink color. (Size, 33mmφ x 150mm/).

The transparent glass base material obtained above was stretched to 2 mmφ,
It was used as a core material. After mirror polishing the cross section of the core material, EP
MA (Electric Probe Micro Analyzer)
When the Erlli degree distribution in the radial direction was measured, it was confirmed that the particles were added uniformly as shown in FIG. 2(A).

In addition, pure Si (h porous base material (80
mmφ×500mmA) was produced. This base material was heat treated under the conditions shown in Table 1 to produce a glass body containing 1.2% by weight of fluorine.

Table 1 Obtained fluorine-containing glass body (size, 35 mmφ x 1
A hole of 2 mmφ was drilled in the 50 mm #) and used as a crat material.

The Er-containing St Ox core material was inserted into the inner-surface-treated fluorine-containing Si○ and cladding material, and the two were heat-fused to form a compound to obtain a preform (31 mmφ x 150 mm).
aunjri. The preform was spun to a core diameter of 8.1μ.
, a single mode fiber with a cladding diameter of 125p. When the optical amplification characteristics of this fiber at 1.535/7 m were investigated, a gain of 17.4 dB was obtained, confirming its effectiveness as an optical amplifier.

Comparative Example 1 A porous matrix was prepared in the same manner as shown in the example, and the Er concentration was 0.05 without applying ultrasound to the porous matrix.
It was impregnated into a mol/l methanol solution. The E-impregnated porous base material was heat-treated under the same conditions as in the example to obtain a pink transparent glass body.The glass body was stretched to a diameter of 2 mm and used as a core material. When the radial distribution was measured, it had a distribution as shown in FIG. 2(B).

The core material was heat-fused and integrated with 1.2% by weight fluorine-containing glass (crat material) in the same manner as in Example 1 to produce a preform, which was further spun to form one of the obtained fibers. When the optical amplification characteristics at .5357J were investigated, the gain remained at 9.5 dB. Note that a 0.514 taAr laser with a power of 50 mW was used as the excitation light.

From the results of Example 1 and Comparative Example 1 above, it is clear that according to the method of the present invention, an oxide additive or a compound that can be converted into an oxide additive by heat treatment can be dispersed and added to a porous glass body very uniformly. Moreover, it can be seen that a larger amount can be added compared to the conventional method that relies solely on osmotic pressure.

Example 2 A porous base material similar to that in Example 1 was prepared. N as a raw material
d Using Cls 6 H20, dissolve it in H20 and make 0,
An aqueous solution of 0.005 mol/l was prepared and impregnated into the P2O5SiO2 soot. At this time, ultrasonic waves of 45 kllz were applied for 30 minutes. The base material impregnated with the aqueous solution has a temperature of 1 at room temperature.
After drying by leaving it in the sun, dry it in a soaking oven.
1 (e-0,2), heat treatment was performed at 1600° C. for 30 minutes to form transparent vitrification.

The Nd content in the base material obtained above was 300 ppm.
Met. This Nd "radial direction Nd of the added glass base material"
When the concentration distribution was measured by STMS (secondary ion mass spectrometry), it was as shown in FIG. 3, and it was confirmed that the concentration distribution was uniform.

The base material was made into a fiber in the same manner as in Example 1, and the fluorescence characteristics of the fiber were evaluated (excitation light Ar laser 50 mW). ] A gain of dB was obtained.

Example 3 fir”! degree 300p manufactured by the same method as Example 1
pm glass base material was stretched to an outer diameter of 12 mmφ, and a tubular glass base material (outer diameter 30+nmφ, inner diameter 1.5 mmφ) made of SiO2 containing 2.6% by weight of fluorine was drawn with [ir SiO2 A glass base material was inserted and heat fused to form a preform. FIG. 4 shows the result of measuring the radial direction Hr"8 degree distribution of the preform by SIMS, and it was confirmed that the distribution was almost uniform in the core portion.

The preform was bowed into a fiber having a diameter of 1 mm. After cleaning the fibers with acid, they were arranged and collapsed in a quartz pipe with a diameter of 30 mm and a wall thickness of 1.5 mm to obtain a 13,000 pixel image fiber preform, with a core diameter of 5.5/ffn. , with a core spacing of 10-. The gain at 1.535 mm was evaluated (using a 50 mW mAr laser with excitation light of 0.514 mm) and found to be 10 c/B. Also, good clarity was obtained.

Example 4 002 mol/l using SmC136H20 as a raw material
Prepare a methanol solution of Ge SiO2
Impregnated into porous matrix. Sm”i!it degree is 500p
It was pm. The same procedure as in Example 2 was performed to obtain a transparent vitrification to obtain a core rod. The glass rod for the core and the pure Si 02 pipe for the crat part prepared separately,
A preform having a crut/core (diameter ratio) of -12 was produced by heat-sealing and integrating by a so-called loft-in-tube method. The results of measuring the radial direction Sm''174 degree distribution of the preform using SIMS are shown in Figure 5.
It was confirmed that the particles were distributed almost uniformly within the core.

The preform was drawn into a fiber with a diameter of 125 mm, and the loss of 1.3/7 m of the fiber was measured (excitation light Ar laser 50 mW) and found to be 12 dB/m.

Second, although Er, Nd, Sm, etc. have been explained as examples, the method of the present invention is also effective in a method in which a porous base material is impregnated with a solution containing a plurality of additives.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to uniformly add additives to the entire base material, which is also effective in improving properties. Therefore, according to the present invention, high quality functional glass can be obtained in optical fiber lasers, optical direct amplifiers, etc.

[Brief explanation of drawings]

Figure 1 is a schematic diagram explaining an embodiment of the present invention, Figure 2 (
A) and (B) are charts showing the results of EPMA analysis, and FIG. Figure 2 (b) shows the Iir-containing glass body obtained in Comparative Example 1 (without ultrasound)
Show things. 3 to 5 are radial concentration distribution maps (by SIMS) of additive elements in the functional glasses of the present invention obtained in Examples 2 to 4. In FIG. 1, l is a porous base material, 2 is a porous base material containing additives, 3 is a solution containing additives, 4 is a solution tank, 5 is an ultrasonic oscillator, 6 is a quartz furnace tube, 7 represents a heater. 4th generation

Claims (1)

[Claims] (1) Oxide additives can be added by impregnating a porous glass base material with a solution containing one or more desired oxide additives or a compound that can be converted into the oxide additive by heat treatment, and then heat-treating the material. A method for producing functional glass, which comprises impregnating a porous base material with the solution while applying ultrasonic waves.