Hydrogenated Silicon-Silver Bandpass Filter for Low Angle Shift
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Solution Overview
Problem
Existing optical filters face challenges in achieving high transmissivity and low angle shift while effectively blocking ambient light, leading to reduced accuracy in optical systems due to material reactivity and complex manufacturing processes.
Innovation Solution
The use of hydrogenated silicon and silver layers in an optical filter, combined with dielectric materials like silicon dioxide, to form a bandpass filter that minimizes reactivity issues and allows for a single sputtering process, enhancing optical performance and manufacturability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical filter materials are used, then manufacturing complexity increases and material reactivity issues occur, but transmissivity and angle shift performance are compromised
Solution Approach 1:
The patent employs a composite material structure consisting of alternating dielectric layers (silicon dioxide, silicon nitride) and metal layers (silver). This composite approach allows each material to contribute its optical properties, achieving high transmissivity in the near-infrared band while blocking ambient light. The composite structure resolves the contradiction by providing stable optical performance through material selection while enabling single-step sputtering deposition, thereby reducing manufacturing complexity.
Solution Approach 2:
The patent optimizes parameters including layer thickness (ranging from a few nanometers to micrometers), refractive index ratios between materials, and metal layer composition to achieve desired optical characteristics. By carefully controlling these parameters, the filter achieves high transmissivity and low angle shift while maintaining stability. The parameter optimization allows for reduced manufacturing complexity through single-step deposition processes.
2Measurement precision
If multiple materials with different refractive indices are used, then transmissivity and angle shift performance improve, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple deposition steps into a single sputtering process, combining the deposition of dielectric and metal layers in one operation. This merging approach maintains the performance benefits of multiple materials with different refractive indices while eliminating the manufacturing complexity associated with sequential deposition processes. The single-step sputtering capability allows for cost-effective production without sacrificing optical accuracy.
3Use of energy by moving object
If silver layers are used for high transmissivity, then optical performance improves, but material reactivity issues arise
Solution Approach 1:
The patent introduces dielectric layers (silicon dioxide, silicon nitride) as intermediary layers between the silver metal layers and the surrounding environment. These intermediary layers serve as protective barriers that prevent direct contact between the silver and reactive substances, thereby maintaining material stability. Simultaneously, the dielectric layers are optimized to maintain high light transmission efficiency in the near-infrared band, resolving the contradiction between optical performance and material stability.
Solution Approach 2:
The composite structure of alternating dielectric and metal layers provides both the optical benefits of silver (high transmissivity) and the stability of dielectric materials. The dielectric layers protect the silver from oxidation and other reactive processes, while the silver layers provide the desired optical characteristics. This composite approach simultaneously achieves high light transmission efficiency and material stability.
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
This configuration achieves improved transmissivity and reduced angle shift, enabling better optical system accuracy and miniaturization with reduced manufacturing complexity and cost.
Implementation Method 1
a first subset of optical filter layers include a first material with a first refractive index... a second subset of optical filter layers include a second material with a second refractive index
Implementation Method 2
allows for a single sputtering process
Data Source
AI summary
An induced transmission filter may include a set of optical filter layers. The set of optical filter layers may include a first subset of optical filter layers comprising a first material with a first refractive index, the first material comprising at least silicon and hydrogen. The set of optical filter layers may include a second subset of optical filter layers comprising a second material with a second refractive index. The second material may be different from the first material and the second refractive index may be less than the first refractive index. The second material may include at least silver.