Spectrally sampled OCT imaging based on 1.7-μm continuous-wave supercontinuum source

We demonstrate a novel multiwavelength light source around the 1.7-μm region based on continuous-wave (CW) supercontinuum (SC) generation for the deeper imaging of low-water-absorption sample with a spectrally sampled optical coherence tomography (OCT) system. This self-regulated Gaussian spectrum of CW SC source has an extremely smooth flat width with more than 210-nm full-width at half-maximum bandwidth centered at the 1.7-μm region, a high output power of 500 mW, and a low temporal instability with less than 0.1 dB for an hour. In order to improve the OCT signal sensitivity without increasing the optical illumination power, a multiwavelength light source based on this CW SC was implemented by using a tunable fiber Sagnac comb filter. When it was applied to the spectrally sampled OCT imaging, the multiwavelength light source enabled a dynamic range improvement, compared to conventional continuous spectral light source with the same average optical power.