Robust numerical phase stabilization for long‐range swept‐source optical coherence tomography

Abstract

A novel phase stabilization technique is demonstrated with significant improvement in the phase stability of a micro-electromechanical (MEMS) vertical cavity surface-emitting laser (VCSEL) based swept-source optical coherence tomography (SS-OCT) system. Without any requirements of hardware modifications, the new fully numerical phase stabilization technique features high tolerance to acquisition jitter, and significantly reduced budget in computational effort. We demonstrate that when measured with biological tissue, this technique enables a phase sensitivity of 89 mrad in highly scattering tissue, with image ranging distance of up to 12.5 mm at A-line scan rate of 100.3 kHz. We further compare the performances delivered by the phase-stabilization approach with conventional numerical approach for accuracy and computational efficiency. Imaging result of complex signal-based optical coherence tomography angiography (OCTA) and Doppler OCTA indicate that the proposed phase stabilization technique is robust, and efficient in improving the image contrast-to-noise ratio and extending OCTA depth range. The proposed technique can be universally applied to improve phase-stability in generic SS-OCT with different scale of scan rates without a need for special treatment.

Optical coherence tomography angiography monitors human cutaneous wound healing over time

“…The system setup was similar to that used in a previous study in our lab (52). In short, a 200-kHz verticalcavity surface-emitting (VCSEL) swept laser source (SL1310V1-20048, Thorlabs Inc., Newton, USA) was used as the light source providing a central wavelength of 1,310 nm (infrared/IR) and a spectral bandwidth of 100 nm, giving an axial resolution of ~8 μm in tissue (~11 μm in air).…”

“…Each B-frame scan was repeated four times at the same position for vascular information extraction using OMAG algorithm (46). Numerical phase-stabilization algorithms were also applied to the complex data for enhanced angiography contrast (52). Next, consecutive cross-sectional positions (10 μm apart) were scanned along a perpendicular axis to the fast axis, i.e., slow axis, to yield a 3D volume scan, i.e., C-scan.…”

Automatic skin lesion area determination of basal cell carcinoma using optical coherence tomography angiography and a skeletonization approach: Preliminary results

“…The post‐processing employs a complex signal–based OCTA algorithm . Motion contrast is achieved by calculating the difference of consecutive B‐scans in the same position.…”

“…The post-processing employs a complex signal-based OCTA algorithm [41,42]. Motion contrast is achieved by calculating the difference of consecutive B-scans in the same F I G U R E 1 Schematic diagram of the optical coherence tomography angiography system used in the experiments position.…”

Flexible wide‐field optical micro‐angiography based on Fourier‐domain multiplexed dual‐beam swept source optical coherence tomography

“…OCT structural image was reconstructed using the modulus of the complex data, and visualized in dB scale. For angiography images at each cross-sectional position, 4 repeated B-scan complex data was firstly processed by the numerical phase-stabilization technique proposed in [38], then eigendecomposition-based clutter filtering technique [7,39] was used for optical microangiography.…”