Photonic Crystal Microcavity Multiplexing for Label-Free Biosensing
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Solution Overview
Problem
Current label-free biosensors and chip-integrated optical absorption spectrometers face limitations in throughput and specificity, particularly in detecting multiple biomolecular interactions simultaneously and achieving wide bandwidth infrared optical absorption measurements.
Innovation Solution
A semiconductor-based sensor system utilizing multimode interference power splitters and photonic crystal waveguides with cascaded stages and impedance tapers, enabling simultaneous interrogation of multiple photonic crystal microcavities with different biomolecule receptors and extending the slow light guiding wavelength range through photonic crystal slot waveguides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple photonic crystal microcavities are arrayed along a single photonic crystal waveguide, then detection throughput and sensitivity are improved, but device complexity and difficulty of simultaneous interrogation increase
Solution Approach 1:
The patent segments the waveguide into multiple sections, each containing photonic crystal microcavities at different positions. This segmentation allows independent addressing and interrogation of different microcavity groups, reducing the complexity of simultaneous interrogation while maintaining high detection throughput through parallel measurement capabilities.
Solution Approach 2:
The patent introduces micropost structures as intermediary elements that couple light from the waveguide to the microcavities. These microposts act as mediators that facilitate selective optical coupling to different microcavity groups, enabling simplified interrogation schemes while maintaining high detection throughput and sensitivity.
2Adaptability or versatility
If photonic crystal slot waveguides are used to extend slow light guiding wavelength range, then infrared absorption spectroscopy bandwidth is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements photonic crystal slot waveguides with locally varied geometries, including regions with different slot widths and hole patterns, to extend the slow light guiding wavelength range. This local quality variation enables broadband infrared absorption spectroscopy while using standard semiconductor fabrication techniques to manage manufacturing precision requirements.
3Measurement precision
If label-free detection is implemented using photonic crystal microcavities, then detection specificity and sensitivity are improved, but difficulty of detecting and measuring multiple simultaneous interactions increases
Solution Approach 1:
The patent segments the detection system into multiple independent photonic crystal microcavity sensing zones, each capable of label-free detection. This segmentation enables simultaneous measurement of multiple biomolecular interactions with high specificity and sensitivity, as each zone can be independently monitored without interfering with others.
Solution Approach 2:
The patent utilizes the spatial dimension along the waveguide to arrange multiple microcavity sensing zones at different positions. This dimensional arrangement allows parallel detection of multiple biomolecular interactions simultaneously, reducing measurement complexity while maintaining high detection sensitivity and specificity through spatially resolved readings.
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 approach enables high-throughput, specific detection of multiple biomolecular interactions and broadens the wavelength range for infrared absorption measurements, enhancing diagnostic assays and sensitivity without the need for label-based detection.
Implementation Method 1
photonic crystal (PC) microcavities, in general, are more compact (of the order of a few square microns in surface area) and have higher sensitivity than other devices due to slow light effect and the larger optical mode overlap with the analyte within compact optical mode volume
Implementation Method 2
Methods to array two-dimensional PC microcavities have primarily focused on the detection of a single bio-molecular probe binding to its specific conjugate target biomolecule on all microcavities. A method to array photonic crystal microcavities along a single photonic crystal waveguide was previously presented in U.S. Pat. No. 8,293,177. Here, we disclose novel methods to array these PC microcavities using multimode interference optical power splitters
Implementation Method 3
chip integrated optical absorption spectrometers are attractive since they allow chemical and biological analytes to be distinguished on a chip with near-infrared optical absorption signatures
Data Source
AI summary
Systems and methods for chip-integrated label-free detection and absorption spectroscopy with high throughput, sensitivity, and specificity are disclosed. The invention comprises packaged chips for multiplexing photonic crystal microcavity waveguide and photonic crystal slot waveguide devices. The packaged chips comprise crossing waveguides to prevent leakage of fluids from the microfluidic channels from the trenches or voids around the light guiding waveguides. Other embodiments are described and claimed.