Compensation of spectral and RF errors in swept-source OCT for high extinction complex demodulation
Optics Express
|April 4, 2015
Summary
We developed a framework to compensate errors in optical coherence tomography (OCT) systems, improving signal separation for better depth imaging. This method enhances extinction ratios in swept-source OCT, enabling more accurate and reliable results.
Area of Science:
- Biomedical Engineering
- Optical Engineering
- Signal Processing
Background:
- Passive optical quadrature demodulation is crucial for swept-source optical coherence tomography (OCT).
- Accurate separation of positive and negative depth signals requires precise demodulation with low amplitude and phase errors (<0.1%).
- Existing methods struggle to achieve low errors across wide spectral and RF bandwidths in high-speed OCT.
Purpose of the Study:
- To present a comprehensive framework for compensating both spectral and radio frequency (RF) domain errors in passive optical quadrature demodulation circuits.
- To improve the extinction ratio between positive and negative depth signals in swept-source OCT systems.
- To provide algorithms for deriving and updating calibration parameters for enhanced OCT performance.
Main Methods:
- Developed a framework to compensate for spectral and RF domain errors in quadrature demodulation.
- Performed stability analysis to determine the longevity of calibration parameters.
- Presented empirical procedures for simultaneous derivation and updating of RF and spectral calibration parameters.
Main Results:
- Demonstrated extinction ratios greater than 60 dB using the proposed compensation framework.
- RF error calibration parameters show stability over several days.
- Spectral error calibration parameters require updates before each imaging session for optimal performance.
Conclusions:
- The developed framework effectively compensates for spectral and RF errors in passive optical quadrature demodulation.
- The findings enable the use of passive optical quadrature demodulation circuits in high-speed, wide-bandwidth swept-source OCT systems.
- The presented algorithms facilitate accurate depth imaging by improving signal separation and reducing errors.
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