Multilayer Optical Interference Filter for Excitation Blocking
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Solution Overview
Problem
Existing optical filters require multiple components and complex processing steps to block excitation light and pass emission light, leading to increased complexity and cost, and suffer from angle-dependent wavelength shifts that degrade sensing accuracy.
Innovation Solution
An optical interference filter with a single coating of multiple layers, including tantalum and oxygen, silicon and oxygen, and hydrogen and silicon, is designed to block excitation wavelengths and transmit emission wavelengths, reducing the need for additional components and minimizing angle-dependent shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple components and complex processing steps are used to block excitation light and pass emission light, then the filtering performance is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple filtering functions (blocking excitation light and passing emission light) into a single optical filter component with a specific multilayer structure. This merging of functions reduces the number of separate components and processing steps while maintaining the required filtering performance, directly resolving the contradiction between filtering reliability and device complexity.
Solution Approach 2:
The optical filter employs a composite multilayer structure comprising different materials (e.g., tantalum oxide, silicon oxide, hydrogenated silicon) with specific optical properties. This composite structure enables simultaneous achievement of excitation light blocking and emission light passing within a single component, reducing overall system complexity while maintaining filtering effectiveness.
2Reliability
If traditional optical filters are used, then the basic filtering function is achieved, but angle-dependent wavelength shifts occur that degrade sensing accuracy
Solution Approach 1:
The patent employs a specific multilayer structure with carefully controlled thicknesses and material compositions to optimize the optical interference characteristics. This parameter optimization reduces angle-dependent wavelength shifts, ensuring that the filter maintains its spectral characteristics across different angles of incidence, thereby improving sensing accuracy while preserving the basic filtering function.
3Ease of manufacture
If a single-coated optical filter is used, then production complexity is reduced, but the ability to block excitation light and pass emission light may be compromised
Solution Approach 1:
The single-coated optical filter uses a composite multilayer structure with different materials (tantalum oxide, silicon oxide, hydrogenated silicon) to achieve the required filtering capability in one component. This composite approach maintains effective excitation light blocking and emission light passing while simplifying production to a single coating process, resolving the contradiction between ease of manufacture and filtering reliability.
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 single-coated optical filter simplifies production, reduces complexity and cost, and improves sensing accuracy by minimizing unwanted light transmission at varying angles of incidence.
Implementation Method 1
an optical interference filter includes a substrate; and a plurality of sets of layers that are disposed over the substrate
Implementation Method 2
the third layer has an extinction coefficient for the second spectral range that is greater than or equal to four times an extinction coefficient of the third layer for the first spectral range
Data Source
AI summary
An optical interference filter includes a substrate and a plurality of sets of layers that are disposed over the substrate. Each set of layers includes: a first layer that comprises at least a first oxide; a second layer disposed over the first layer that comprises at least a second oxide; and a third layer disposed over the second layer that comprises at least hydrogen and silicon. The optical interference filter may be configured to transmit light associated with a first spectral range (e.g., from 585 nanometers to 700 nanometers) and to block light associated with a second spectral range (e.g., from 440 nanometers to 475 nanometers). The third layer may have an extinction coefficient for the second spectral range that is greater than four times an extinction coefficient of the third layer for the first spectral range.