High-speed linear detection time domain optical coherence tomography with reflective grating-generated spatial reference delay.

We developed a high-speed linear detection time-domain optical coherence tomography (OCT) technique that detected a reflective grating-generated spatial optical delay in the reference arm using a line scan camera during probe-beam scanning. Using an InGaAs line scan camera (512 pixels) operating at 47,000 lines/s, the calculation of the absolute value of the difference between two sequential lines can be approximately displayed as cross-sectional images with 500 lateral pixels at 94 frames/s . After data acquisition, we performed postprocessing that involves a Hilbert transform to improve the image quality of an OCT image. Our OCT system was successfully used to image a human finger in vivo with 93 dB sensitivity.