Utility of spectral leakages to the depth profile using sub-bin in spectral-domain optical coherence tomography

We propose an amplitude-signal-to-noise ratio (A-SNR) method to utilize the spectral leakage components in the depth profile using a sub-bin (SB) in spectral domain optical coherence tomography (SD-OCT). The conventional bin interval was divided by the SB, and a rectangular spectral density was used. The amplitude and SNR under SB conditions were derived theoretically, and the simulation results are presented. In experiments, using SD-OCT with a 0.8 µm SLD, for the conventional depth resolution of 19.1 µm, the displacements of 2-3 µm in depth were measured using the proposed method. The example of applications of the A-SNR method is also discussed.