SnO2-Refined Optical Glass for Solarization Resistance

Solution Overview

Problem

Current fiber-optic light guides face challenges with high attenuation, solarization, and the use of toxic refining agents, which affect their performance and environmental sustainability, particularly in medical and telecommunications applications where low color temperature shift and resistance to alkaline solutions are crucial.

Innovation Solution

A glass composition with specific components such as SnO2, Al2O3, and ZrO2, refined using SnO2 as a refining agent, which reduces Fe2+/Fe3+ ratio and minimizes solarization, achieving low attenuation and high chemical resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional refining agents (As2O3, Sb2O3) are used to reduce Fe2+ content and achieve low attenuation, then attenuation is improved, but solarization resistance deteriorates and environmental safety worsens

Engineering Contradiction:

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent removes toxic refining agents (As2O3, Sb2O3) from the glass composition and replaces them with SnO2. This extraction of harmful substances eliminates the solarization problem and environmental safety issues while maintaining the ability to refine Fe2+ content through alternative mechanisms.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters by introducing SnO2 as a refining agent and adjusting the Fe2+/Fe3+ ratio through controlled oxidation. This parameter change enables achieving low attenuation without the solarization side effects of conventional refining agents.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If PbO is added to improve solarization resistance, then solarization resistance is improved, but environmental safety deteriorates

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts PbO from the glass composition and replaces it with SnO2 as the refining agent. This removal of toxic lead oxide eliminates environmental safety concerns while SnO2 provides the necessary solarization resistance through its ability to control Fe2+ content without the harmful side effects of lead.

Inventive Principle:

Principle #2Taking out (Extraction)

3Loss of energy

If high purity raw materials are used to reduce attenuation, then attenuation is improved, but manufacturing cost increases

Engineering Contradiction:

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent introduces SnO2 as an intermediary refining agent that enables the use of standard purity raw materials. SnO2 acts as a mediator that chemically processes and removes Fe2+ impurities during melting, achieving low attenuation without requiring expensive high-purity raw materials.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Loss of energy

If Fe2+ content is reduced to achieve low attenuation, then attenuation is improved, but solarization resistance may deteriorate if conventional refining agents are used

Engineering Contradiction:

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent converts the potential harm of Fe2+ reduction (which can lead to solarization with conventional agents) into a benefit by using SnO2 as the refining agent. SnO2 enables Fe2+ removal through oxidation to Fe3+ without introducing the solarization problem, effectively turning a potential harm into a beneficial outcome.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 glass exhibits low attenuation across a wide wavelength range, excellent solarization resistance, and compatibility with alkaline solutions, making it suitable for medical and telecommunications applications with minimal environmental impact.

Implementation Method 1

SnO2 as a refining agent, which reduces Fe2+/Fe3+ ratio

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

exhibiting very good resistance to solarization

Methodology Applied

Scientific EffectSolarization resistance:

Implementation Method 3

The glass exhibits low attenuation across a wide wavelength range

Methodology Applied

Scientific EffectLight transmission:

Implementation Method 4

compatibility with alkaline solutions

Methodology Applied

Scientific EffectChemical resistance:

Data Source

PatentEP3782961B1Highly transmissive glasses with high solarisation resistance, use thereof and method for production thereof

Publication Date: 2023.12.20

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AI summary

This invention relates to glasses that are highly transparent and exhibit very good resistance to solarization. The good resistance to solarization is particularly enhanced by the manufacturing process. The concentrations of reduced species of polyvalent ions are decreased by the targeted use of bubbling with an oxidizing gas. The invention also relates to a method for producing glasses according to the invention and their uses, especially as core glasses in optical fibers. Furthermore, this invention relates to an optical fiber comprising the glass according to the invention as a core glass and a cladding glass.