Chemically Strengthened Waveguide Glass for Low Cross-Talk Optics
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Solution Overview
Problem
Existing optical waveguides and glass compositions lack sufficient scratch resistance, damage resistance, and optical properties for effective light collection and transmission in optical sensors and consumer electronic devices, particularly when using ion-exchangeable glasses.
Innovation Solution
A waveguide design featuring a core material with high refractive index, stabilized by Ta2O5, and a cladding material with low transmittance, both chemically strengthened to enhance scratch resistance and optical properties, allowing for improved light collection and transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional ion-exchangeable glass compositions are used, then the glass can be chemically strengthened, but the scratch resistance and damage resistance remain insufficient
Solution Approach 1:
The patent modifies the chemical composition parameters of the glass by incorporating specific amounts of Ta2O5 (1-30 mol%) and Fe2O3 (0.03-5 mol%) to achieve both high scratch resistance and adequate damage resistance while maintaining ion-exchangeability for chemical strengthening
Solution Approach 2:
The patent creates a composite glass composition combining multiple oxides (SiO2, Ta2O5, Fe2O3, Li2O, Na2O, Al2O3, B2O3) where each component contributes specific properties: Ta2O5 for scratch resistance, Fe2O3 for low transmittance, and the base glass matrix for ion-exchangeability
2Illumination intensity
If high refractive index components are added to increase light collection, then optical properties improve, but the glass composition becomes unstable and prone to devitrification
Solution Approach 1:
The patent optimizes the concentration parameters of high refractive index components, specifically limiting Ta2O5 to 1-30 mol% and Fe2O3 to 0.03-5 mol%, which provides sufficient refractive index (≥1.60) while maintaining glass stability and preventing devitrification
Solution Approach 2:
The patent uses Ta2O5 as an intermediary component that stabilizes other high refractive index components and prevents phase separation, allowing the glass to maintain both high refractive index and compositional stability
3Productivity
If the cladding material has high transmittance to allow light passage, then signal transmission is enabled, but cross-talk between adjacent signals increases
Solution Approach 1:
The patent applies different optical properties to different regions: the core material has high transmittance (70-96%) for signal transmission, while the cladding material has low transmittance (≤5%) to prevent cross-talk, with each region optimized for its specific function
Solution Approach 2:
The patent uses Fe2O3 in the cladding composition to optically darken the cladding material, reducing its transmittance to ≤5% and thereby preventing harmful cross-talk between adjacent waveguide sections
4Illumination intensity
If Ta2O5 is used to increase refractive index, then optical properties improve, but the glass composition becomes unstable and prone to phase separation
Solution Approach 1:
The patent optimizes the concentration of Ta2O5 within 1-30 mol% and combines it with specific amounts of stabilizing components (SiO2: 59-80 mol%, Li2O: 4.5-10 mol%, Na2O, Al2O3, B2O3) to achieve refractive index ≥1.60 while preventing phase separation and maintaining compositional stability
Solution Approach 2:
The patent uses Ta2O5 as a stabilizing intermediary that prevents phase separation of other high refractive index components in the glass composition, allowing the system to maintain both high refractive index and compositional homogeneity
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 waveguide design provides enhanced scratch resistance, improved optical properties, and reduced signal cross-talk, enabling efficient light collection and transmission, suitable for optical sensors and consumer electronics.
Implementation Method 1
the core material having a higher refractive index than the cladding material... the waveguide to receive (e.g., couple into an end) and transmit light due to the high acceptance angle
Implementation Method 2
the core material is chemically strengthened and has a core compressive stress and a core central tension, the cladding material is chemically strengthened and has a clad compressive stress and a clad central tension
Implementation Method 3
the cladding material having a low transmittance... can inhibit the transmission of signals therethrough, which can function to prevent cross-talk between signals in adjacent sections of core material
Data Source
AI summary
Waveguide have a cladding material attached to and circumferentially surrounding a core material. The cladding material can be a polymer-containing material or a glass-based material that is fused to the core material. Both the cladding material and core material can be chemically strengthened to have a central tension of at least 30 MPa. An absolute value of a difference in refractive index between the cladding material and the core material is from 0.10 to 0.30. The cladding material can be a boroaluminosilicate composition having from 0.03 mol % to 5.0 mol % Fe2O3. The core material can have from 59 mol % to 80 mol % SiO2 and from 1.5 mol % to 30 mol % Ta2O5. In aspects, the core material can have at least 0.1 mol % Li2O and at least 0.2 mol % Na2O. Methods include redrawing and thermally conditioning an assembly comprising a core material inserted in a preform to form a fused waveguide.