JPS61151034A - Quartz laser glass for amplifying infrared light - Google Patents

Abstract

PURPOSE:To produce the titled glass having stable heat-expansion coefficient and optical length and high heat conductivity, usable stably, and enabling the continuous oscillation and amplification of infrared radiation, by compounding Er2O3, Nd2O3, Yb2O3, Mo2O3, Al2O3, P2O5 and SiO2 at specific ratios. CONSTITUTION:The objective infrared amplifying quartz laser glass can be produced by compounding 0.1-15(wt)% Er2O3, 0.2-15% Nd2O3, 0.2-15% Yb2O3, 0.2-15% Mo2O3 (Nd2O3+Yb2O3+Mo2O3=0.2-15%), 1-20% Al2O3, 1-20% P2O5 (Al2O3+P2O5=1-20%), and the remaining part of SiO2.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a quartz laser glass, and more specifically, it can be used as a material for amplifying optical communication or as an oscillating material for laser light in the 1.5μ band, which has the least absorption loss, so it can be used for optical fibers. The present invention relates to quartz laser glass that can be used for detecting break points and can be applied to measuring instruments such as range finders.

(Prior Art) Light emitting diodes are generally used for amplification in optical communications, but this quartz laser glass fiber can be used by directly connecting to an optical fiber.

Furthermore, although semiconductor lasers in the 0.8μ or 1.3μ band have conventionally been mainly used as oscillation materials, our quartz laser glass can oscillate laser light in the 1°5μ band with the least absorption loss. Problems to be Solved by the Invention) The glass has significantly lower nonlinear refractive index, thermal expansion coefficient, and thermal conductivity than conventional silicate-based and phosphate-based laser glasses, and has high ultraviolet transmittance and water resistance. The purpose of this invention is to provide laser glass with excellent properties.

(Means for Solving the Problems) The inventors of the present invention conducted various studies in search of the above-mentioned objective laser glass, and as a result, discovered that a quartz laser glass having the following composition has the following features.

The composition weight % of the quartz laser glass of the present invention is E r20. ; 0.1-15. Nd2O
3; 0.2-15. Yb20s; 0, 2~l 5
, M o a O3; 0.2-15, Nd2O3+Y
b, ○, +MoO,; 0.2-15, Al2O3; 1~
20. P2O3;1-20. A1. O,+P,O,;
1-20. Remaining) Quartz laser glass made of JSi○2 Features of the quartz laser glass of the present invention (1) The coefficient of thermal expansion is extremely small, so it can be used stably with little change in optical path length (2) It has good thermal conductivity, so it can be used continuously (3) Our quartz laser glass can be used as a medium for oscillation and amplification. (3) Our quartz laser glass can effectively use optical absorption in the ultraviolet region, increasing excitation efficiency. (4) Our quartz laser glass has good water resistance and is heat resistant. (5) Our quartz laser glass has good optical homogeneity and is extremely unlikely to be damaged by lasers. (6) The oscillation wavelength of our quartz laser glass is such that transmission loss in silica glass-based optical communications is low. The minimum value is 1.55μ. (7) The above-mentioned characteristics of this quartz laser glass are as follows: Nonlinear refractive index: 0.6XIO-"esu Coefficient of thermal expansion:
5~10 x 10-7/”C thermal conductivity 0
．． 030~0.035cal/cm sec"c Water resistance (wtloss%) (Hz O100"CC1h)0
．． 000 or less Ultraviolet transmittance 50% or less (lo+++
/m200'm) Homogeneity 4X10''S or less.

(Function) In the quartz laser glass, Er20a is Er”
The preferable concentration range of Er2O, which acts as an ion for emitting laser light, is 0.1 to 15%. If it exceeds 15%, concentration quenching occurs and the peak is not sharp.

Nd*Oa and YbtOz-Mozoa are each Nd''.

Yb" and Mo"K act as laser sensitizing ions and are added singly or in combination.

This preferred concentration range is Nd, O,; 0.2 to 0.2% by weight.
15. Yb, O,; 0.2-15. Mo, On; 0.
2-15, Nd2O3+Y,b,O,+MozOi;0
．． 2 to 15.

A1□0. and P, ○, act to introduce luminescent ions or sensitizing ions such as N d '' into the 5i-0 network structure of the matrix quartz glass, and exhibit effective fluorescent properties. A range of 20 wt% is preferred.

The quartz laser glass having the above composition range exhibits the following characteristics.

0 Laser characteristics Er20. (wt%) 0.2 to 5% Stimulated emission cross section σρ (10″″″’cm”) 2.2 to 5
Fluorescence lifetime (μ5ec) 250-400 oscillation wavelength (
μm) 1.550 Laser damage threshold (ln
sec pulse) (J/c♂) Surface damage
20-25 Internal damage 30-40 0 Optical properties Nonlinear refractive index n, (X 10-13e su) 0
．． 6 Refractive index (1,55μ) 1,440-1,460
Atsbe number (νd) 68 Brewster angle 55"13'~55°34' Coefficient of linear expansion (10-'/'C) 0.5-0.9 Temperature coefficient of refractive index 1.OX 10-'/'C (0-10
0°C) Temperature change in optical path length 5.0 to 5.40 Thermal characteristics Thermal conductivity (25°C) (c a 1/cm s e
c'c) 0.030-0.035 0 Its low characteristic Knoop hardness 100 g) (1 kg g f /mm") 590
~620 (Production method) The quartz laser glass of the present invention is basically produced by flame oxidation decomposition and melting (Flame oxidation decomposition melting).
A hydrolysis method, a soot impregnation method, or a sol-gel method is used.

Flame oxidation decomposition melting is a method of adding compounds of components constituting quartz laser glass during direct high-temperature oxidation, such as the Bertai method and high-frequency oxygen plasma method.

For example, vapors of halides of each element constituting quartz laser glass are introduced into an oxygen plasma flame. A low boiling point halogenated compound, such as SiO, (silica), silicon tetrachloride (SiC1,) p, o as a source, phosphorous oxychloride (POCl,) as a source, and a high boiling point halogen introduced together with argon (Ar) as a carrier gas. Compound AlC
l□.

NdC1, ErC1, YbC1, MOCl are heated to a high temperature and have a high vapor pressure, and are introduced into the flame in predetermined amounts individually or as a mixture.

As an alternative method to the above methods, there is a CVD method (VAD method as a modified method) which is also used for manufacturing optical fibers. Hydrolyzed soot-like oxides of silicon halides are deposited on a support in an oxyhydrogen flame at low temperatures.

The pores of this soot-like silica deposit are impregnated with an alcohol solution of a halide of an added element at room temperature, and after removing the dry alcohol, He, Ca1.
It is heated in an atmosphere to obtain a transparent quartz glass body. In the sol-gel method, an alkoxide solution of an additive element or an inorganic or organic compound is introduced into a dispersion colloidal sol of silicon alkoxide solution or its hydrolyzed product, silica gel, or flame-decomposed oxide of silicon halide (e.g. fumed silica). The resulting mixed gel is carefully heated to 1000 DEG C. and, if necessary, treated with He-Cl□ to obtain a quartz glass body, which can be applied to the manufacture of 1-quartz laser glass.

The quartz laser glass body made by the above method is processed into fibers by cutting into tubes and rods at high temperatures.

(Effects) Since the quartz laser glass of the present invention has an extremely smaller coefficient of thermal expansion than all other materials, it can be stably used with little change in optical path length. Moreover, since it has good thermal conductivity, continuous wave amplification is possible.

Also, 1.55 has the lowest transmission loss among silica-based optical fibers.
Capable of oscillating in the μ band. The light transmittance in the 1.55μ band is approximately 1
It is 00%. Furthermore, it has good water resistance, is resistant to burnout, is optically stable, has good optical homogeneity, and is extremely resistant to laser damage.

The quartz laser glass has been found to have the above-mentioned features and can achieve the above-mentioned purpose.

Claims (1)

[Claims] Er_2O_3; 0.1-15, Nd_2O_ in weight%
3; 0.2-15, Yb_2O_3; 0.2-15, M
o_2O_3; 0.2-15, Nd_2O_3+Yb_
2O_3+Mo_2O_3; 0.2-10, Al_2O
_3; 1-20, P_2O_5; 1-20, Al_2O
_3+P_2O_5; 1 to 20, remaining SiO_2 quartz laser glass