Microchannel Optical Filter for High-AOI Light Rejection
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Solution Overview
Problem
Existing optical filters struggle to effectively reject high-angle of incidence (AOI) light, which interferes with accurate analyte measurements in biosensors by shifting the filter window towards the excitation light source.
Innovation Solution
A microchannel-based optical filter device with a surface-treated microchannel, featuring an arrangement of grooves etched into the walls of the microchannel, which absorbs, traps, and blocks high-AOI light, improving optical rejection while maintaining high light throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional optical filter is used to separate excitation light from emission light, then the filter window shifts to shorter wavelengths (blue shift) as the angle of incidence increases, but this causes the emission filter window to shift towards the excitation light source, reducing rejection effectiveness
Solution Approach 1:
The optical filter is segmented into multiple functional layers: a microlens array that divides incident light into multiple beams at different angles, and multiple optical filters (including long-pass and band-pass filters) that process different angular segments. This segmentation allows each filter to operate at optimized angles, preventing the blue shift problem that affects conventional single-filter designs.
Solution Approach 2:
The patent transitions from a single-angle-of-incidence filter design to a multi-dimensional angular distribution system. The microlens array spreads light across multiple angles, and the system processes light in angular space rather than relying on a single angular path. This dimensional change in angular space allows the filter to maintain stable wavelength characteristics across varying incidence angles.
2Measurement precision
If the optical filter rejects excitation light at high angles of incidence, then measurement accuracy improves, but light throughput decreases because more emission light is also blocked
Solution Approach 1:
The system dynamically processes light by angular distribution. The microlens array continuously redirects light at different angles to different filter elements, creating a dynamic angular separation that adapts to the incoming light distribution. This dynamic approach allows the system to reject excitation light at high angles while maintaining throughput for emission light at optimized angles.
Solution Approach 2:
The microlens array acts as an intermediary element between the incident light and the optical filters. It mediates the angular distribution of light, directing excitation light at high angles to rejection filters while steering emission light through filters at optimized angles. This intermediary structure enables selective angular processing that simultaneously achieves high rejection and maintained throughput.
3Device complexity
If a single optical filter is used for wavelength separation, then device complexity is low, but the ability to reject excitation light at varying angles of incidence is insufficient
Solution Approach 1:
The filter system is segmented into multiple specialized filters: long-pass filters for blocking excitation light at certain angles, band-pass filters for transmitting emission light at optimized angles, and the microlens array as a segmentation element that divides the angular spectrum. This segmentation allows each component to be optimized for its specific function, achieving high reliability across the full AOI range.
Solution Approach 2:
The microlens array provides multi-functionality by simultaneously performing beam division, angular distribution, and light steering functions. A single optical element accomplishes what would otherwise require multiple separate optical components, maintaining relative simplicity while achieving sophisticated angular-selective filtering across the entire field of view.
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 microchannel-based optical filter device achieves high optical rejection of high-AOI light, rejecting excitation light at orders of magnitude greater than emission light power, thereby enhancing the accuracy of analyte measurements.
Implementation Method 1
A microlens array is provided that receives the incident light and transforms the incident light into multiple light beams, each at a different angle
Implementation Method 2
Optical filters are provided that process the light beams and reject light beams that are at angles greater than a maximum acceptance angle
Implementation Method 3
An optical detector is provided that detects light from the implantable sensor
Data Source
AI summary
An optical filter device, system, and methods for improved optical rejection of high angle of incidence (AOI) light is disclosed. For example, an analyte detection system is provided that includes an excitation light source for illuminating an implantable sensor and an optical detector for collecting emission light from the implantable sensor. Further, the optical detector portion of the analyte detection system features an optical filter device including a surface-treated microchannel wherein the surface-treated microchannel serves to absorb, trap, and/or block high-AOI light. Further, a method of operation of the presently disclosed microchannel-based optical filter device including a surface-treated microchannel is provided with respect to the high optical rejection of high-AOI light.