Arc-Plasma Quartz Glass for UV-Resistant YAG Laser Optics

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Solution Overview

Problem

Existing methods for producing quartz glass do not provide sufficient ultraviolet resistance, especially against higher-order harmonics of YAG lasers, and involve complex processes that increase costs.

Innovation Solution

A method involving the use of synthetic silica powder with low impurity and OH group concentrations, melted using arc plasma, to produce quartz glass with enhanced ultraviolet resistance, particularly against the fourth harmonic of a YAG laser.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If synthetic quartz glass is used for higher-order harmonic laser optical members, then transmittance is maintained, but ultraviolet resistance and durability are insufficient

Engineering Contradiction:
Improveultraviolet resistanceVSAvoidproduction process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the chemical composition parameters of the quartz glass by adding specific amounts of Al2O3 (0.1-5 wt%), B2O3 (0.1-5 wt%), and SiO2 (90-99.8 wt%) to improve ultraviolet resistance against fourth harmonic laser while maintaining transmittance properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite glass material by combining multiple oxides (Al2O3, B2O3, SiO2) in specific proportions to achieve enhanced ultraviolet resistance while maintaining the optical properties of quartz glass

Inventive Principle:
Principle #40Composite materials

2Reliability

If existing production methods are used for ultraviolet-resistant quartz glass, then some ultraviolet resistance is achieved, but production processes become complicated and costs increase

Engineering Contradiction:
Improveultraviolet resistanceVSAvoidproduction process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent performs preliminary purification of raw materials to achieve low impurity concentrations (Fe2O3: 0.01-1 ppm, Al2O3: 0.01-1 ppm, B2O3: 0.01-1 ppm) before melting, which simplifies the overall production process by preventing contamination during melting and eliminating the need for complex post-processing purification steps

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent optimizes the chemical composition parameters within specific ranges (Al2O3: 0.1-5 wt%, B2O3: 0.1-5 wt%, SiO2: 90-99.8 wt%) to achieve the desired ultraviolet resistance while maintaining ease of manufacture through controlled melting processes

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The produced quartz glass exhibits high durability against the fourth harmonic of a YAG laser, with ultraviolet resistance exceeding 6,000 seconds and minimal impurity and OH group concentrations.

Implementation Method 1

a quartz glass obtained using a silica powder as a raw material and arc plasma melting it

Methodology Applied
Scientific EffectArc plasma: Plasma

Data Source

PatentEP3617159B1Method for manufacturing ultraviolet-resistant quartz glass and its use
Publication Date: 2025.07.23 TOSOH SGM CORPORATION

AI summary

The present invention pertains to: a method for manufacturing an ultraviolet-resistant quartz glass, said method including melting a synthetic silica powder; and a method for manufacturing an ultraviolet-resistant quartz glass, said method including performing arc plasma melting of a silica powder. Provided is an ultraviolet-resistant quartz glass having an ultraviolet-resistance of 2500 seconds, wherein, taking the initial transmittance during irradiation of a quadruple higher harmonic (266 nm) of a YAG laser (irradiation performed at a YAG laser output of 180 mW, pulse width of 20 nsec, and frequency of 80 kHz) at an optical path length of 30 mm to be 100%, the irradiation period until the transmittance falls to 3% is defined as resistance to ultraviolet rays (referred to as ultraviolet-resistance). Also provided is an optical member for YAG-laser higher harmonics, said optical member comprising this quartz glass.