Bi-directional Optical Switch for Multi-channel OCT Signal Interrogation
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Solution Overview
Problem
Current multi-channel Optical Coherence Tomography (OCT) signal interrogation techniques are costly and inefficient, particularly for commercial applications, due to high costs, bulk size, and unsuitability for balanced detection, which reduces measurement sensitivity.
Innovation Solution
A signal interrogation system utilizing a bi-directional optical switch with 16 switchable channels, an optical coupler, and a balanced photo detector to split and direct laser beams, enabling efficient interference signal measurement and background reduction, thereby achieving cost-effective and sensitive multi-channel OCT imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple photo detectors and fiber circulators are used for multi-channel OCT signal interrogation, then measurement sensitivity is improved through balanced detection, but system cost and device complexity increase significantly
Solution Approach 1:
The patent combines multiple signal interrogation channels into a single detection path by using an optical switch to sequentially route signals from multiple probe channels to one photo detector. This merging approach eliminates the need for multiple photo detectors and fiber circulators, reducing system complexity and cost while maintaining the capability for balanced detection through sequential measurement of reference and sample signals.
Solution Approach 2:
The patent introduces dynamic signal routing using an optical switch that sequentially connects different probe channels to the detection system. This dynamic switching enables a single photo detector to serve multiple channels over time, replacing static one-to-one detector-channel mappings. The dynamic approach maintains measurement sensitivity through balanced detection while reducing the number of physical components required.
2Measurement precision
If multiple photo detectors and fiber circulators are used for multi-channel OCT, then balanced detection capability is achieved, but system cost increases by over $30,000 for 16 channels
Solution Approach 1:
The patent makes a single photo detector universal by using it to serve all 16 probe channels sequentially through optical switching. The same detector performs balanced detection for every channel, eliminating the need for 16 separate detector assemblies. This multi-functional approach reduces the bill of materials cost from over $30,000 to a fraction of that amount, making the system economically viable for commercial deployment.
Solution Approach 2:
The patent creates a time-multiplexed copy of the balanced detection function for each channel rather than providing simultaneous physical detection paths. The single detector sequentially measures reference and sample signals for each channel, creating virtual detection paths that replicate the balanced detection capability without requiring duplicate hardware for each channel.
3Adaptability or versatility
If traditional multi-channel OCT interrogation is used, then multiple channels can be monitored, but the bulk size and cross-talking problems persist
Solution Approach 1:
The patent transitions from a spatial arrangement where each channel has its own detection path to a temporal arrangement where a single detection path serves all channels sequentially. By moving the multiplexing function from the spatial domain to the temporal domain through optical switching, the system maintains multi-channel monitoring capability while dramatically reducing the physical footprint and eliminating cross-talk between channels.
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 system significantly reduces costs by 94% for 16-channel OCT, enables balanced detection to enhance measurement sensitivity, and eliminates the need for multiple photo detectors and fiber circulators, making it suitable for commercial use.
Implementation Method 1
When lights reflected from samples interfere with a reference beam, the frequencies of the interfering signals reveal the depth where the light is reflected
Implementation Method 2
a balanced photo detector to measure a power difference between the interference optical signals and the power reference
Data Source
AI summary
A signal interrogation system comprises an optical coupler to split input laser beam into a first laser beam as a power reference and a second laser beam, the optical coupler being coupled to a first path for the first laser beam and a second path for the second laser beam; an optical circulator disposed in the second path; a bi-directional optical switch disposed in the second path and having on one side a single channel end oriented toward the optical circulator and on another side multiple channel ends with multiple switchable channels; a plurality of optical fibers coupled to the multiple channel ends of the bi-directional optical switch; an interference optical signals path coupled to the optical circulator to receive the interference optical signals from the bi-directional switch; and a balanced photo detector to measure a power difference between the interference optical signals and the power reference.