High-speed Doppler OFDI using frequency multiplexed dual beam illumination

초록

Doppler optical coherence tomography enables high resolution imaging of spatially-localized motion in the sample, especially in-vivo microvasculature imaging, utilizing the phase-resolved technique based on the detection of the phase shift between two temporally separated A-lines. We present high-speed Doppler OFDI using frequency multiplexed dual beam illumination. The novel scheme provides a pair of spatially sseparated beams with an acousto-optic frequency shifter that illuminate the exactly same location on the sample with an adjustable time interval upon the imaging beam scan by the galvanometer. We demonstrate high-speed vasculature imaging of a mouse thigh in-vivo at 117.4 fps (1024 A-lines per frame) over 7mm x 4mm. The 3D vasculature over 7mmx3.7mmx4mm volume is obtained in 4.41s.