Tunable Light Source Resonator Length Matching for OCT Disturbance Reduction
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Solution Overview
Problem
Existing swept source optical coherence domain reflectometry and tomography systems face challenges in achieving high-resolution whole-eye scans due to disturbance signals from interference at disturbance points, leading to inaccurate measurements and reduced signal quality, especially in long-coherent systems with large measurement regions.
Innovation Solution
A device with a tunable light source having a resonator length matched to the interferometric measurement arrangement, ensuring that disturbance points do not create signals within the measurement region by satisfying specific path length conditions, thereby minimizing interference and enhancing signal clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the resonator length of the tunable light source is matched to the measurement region, then measurement precision is improved, but disturbance signals from interference at disturbance points worsen signal quality
Solution Approach 1:
The resonator length LR of the tunable light source is specifically adjusted to satisfy the condition LR > 2·ZOCT, where ZOCT is the measurement region depth range. This parameter change ensures that disturbance signals from interference at disturbance points fall outside the measurement region, thereby improving measurement precision while eliminating harmful disturbance signals within the measurement range.
2Reliability
If the resonator length is increased to suppress disturbance signals, then signal quality is improved, but device complexity increases
Solution Approach 1:
Instead of adding complex signal filtering or processing systems, the invention simply adjusts the resonator length parameter LR to be greater than twice the measurement region depth ZOCT. This straightforward parameter change suppresses disturbance signals and improves signal quality without increasing device complexity.
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 solution effectively suppresses disturbance signals, allowing for precise and accurate whole-eye scans with improved signal quality, even in systems with large measurement regions, by ensuring the resonator length of the light source aligns with the interferometric arrangement, thus reducing errors and enhancing measurement fidelity.
Implementation Method 1
coherent light is, with the aid of an interferometer, used for distance-measuring and imaging purposes
Implementation Method 2
The interference of the signals from both arms results in a pattern, from which it is possible to determine the scattering amplitudes
Implementation Method 3
compares the run-time of a signal with the aid of an interferometer
Data Source
AI summary
Optimized device for swept source optical coherence domain reflectometry and tomography. In the coherence-optical device, light, with the aid of an interferometer, is used for distance-measuring and imaging purposes on reflecting and scattering areas of the human eye. The optimized device according to the invention consists of includes a tunable light source, matched to the sought-after measurement region ZOCT, with a resonator length LR, an interferometric measurement arrangement, a data capturing unit for capturing the light portions scattered back from the sample and a data processing unit. Here the resonator length LR of the tunable light source is matched not only to the sought-after measurement region ZOCT, but also to the entire interferometric measurement arrangement such that disturbance points present in the interferometric measurement arrangement cannot create disturbance signals in the sought-after measurement region ZOCT.