Electro-Optic Composite Substrate with Low-Index Optical Buffer
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Solution Overview
Problem
Conventional composite substrates for electro-optic elements face issues such as separation and cracking due to adhesive degradation, leading to non-flat interfaces and light diffusion or absorption, which affect the performance and durability of the electro-optic elements.
Innovation Solution
A composite substrate design that bonds an electro-optic crystal substrate directly to a support substrate via an amorphous layer, with a low-refractive-index layer interposed between the electro-optic crystal substrate and the amorphous layer, preventing direct contact and minimizing light diffusion or absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to bond the electro-optic crystal substrate and support substrate, then bonding strength is improved, but reliability deteriorates due to adhesive degradation over time causing separation and cracking
Solution Approach 1:
The patent removes the adhesive layer from the bonding structure, eliminating the source of degradation. The electro-optic crystal substrate is directly bonded to the support substrate through surface contact and atomic diffusion, forming a stable interface without organic materials that degrade over time.
Solution Approach 2:
A buffer layer is introduced between the electro-optic crystal substrate and support substrate to facilitate direct bonding. This buffer layer enables atomic diffusion and covalent bond formation while preventing direct contact between the crystal substrate and support substrate, ensuring both strength and long-term reliability.
2Reliability
If the electro-optic crystal substrate is directly bonded to the support substrate without adhesive, then reliability is improved by avoiding adhesive degradation, but optical performance deteriorates due to formation of an amorphous layer with non-flat interface causing light diffusion and absorption
Solution Approach 1:
A buffer layer is introduced as an intermediary between the electro-optic crystal substrate and support substrate. This buffer layer prevents direct contact between the crystal substrate and the amorphous layer, eliminating light diffusion and absorption at the interface while still enabling direct bonding for reliability.
Solution Approach 2:
The bonding interface is segmented into multiple functional layers: the electro-optic crystal substrate, the buffer layer, and the support substrate. This segmentation allows each layer to perform its specific function - the buffer layer creates a flat interface for optical performance while the direct bonding provides reliability.
3Ease of manufacture
If a low-refractive-index layer is added between the electro-optic crystal substrate and amorphous layer, then optical performance is improved by suppressing light diffusion and absorption, but device complexity increases
Solution Approach 1:
The buffer layer serves multiple functions simultaneously: it acts as a bonding interface enabling direct bonding for reliability, provides a flat interface to prevent light diffusion for optical performance, and can be configured with appropriate refractive index to suppress light leakage. This multi-functionality reduces the need for additional separate components.
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 design enhances the performance and durability of electro-optic elements by suppressing light leakage and absorption, enabling high-quality light transmission and reducing dielectric loss, while maintaining structural integrity without adhesive-related deterioration.
Implementation Method 1
a low-refractive-index layer located between the electro-optic crystal substrate and the amorphous layer and having a lower refractive index than the electro-optic crystal substrate
Implementation Method 2
an amorphous layer constituted of elements of the electro-optic crystal substrate and elements of the support substrate
Data Source
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AI summary
A composite substrate for an electro-optic element is disclosed. The composite substrate includes: an electro-optic crystal substrate having an electro-optic effect; a support substrate bonded to the electro-optic crystal substrate at least via an amorphous layer; and a low-refractive-index layer located between the electro-optic crystal substrate and the amorphous layer and having a lower refractive index than the electro-optical crystal substrate. The amorphous layer is constituted of one or more elements that constitute a layer or a substrate contacting the amorphous layer from one side and one or more elements that constitute a layer or a substrate contacting the amorphous layer from another side and has a thickness of 0.1 nanometer or more and 100 nanometers or less.