Quasi-supercontinuum generation using 1.06 μm ultrashort-pulse laser system for ultrahigh-resolution optical-coherence tomography.

We demonstrate quasi-supercontinuum (quasi-SC) generation around the 1.3 μm wavelength region using ultrahigh-speed, wavelength-tunable, femtosecond soliton pulses based on an ultrashort-pulse laser system operating at a wavelength of 1.0 μm. The wavelength tuning range was from 1.0 to 1.9 μm, and the scanning speed was up to 1.3 MHz. A Gaussian-like quasi-SC with a bandwidth of 220 nm was generated at 1220 nm. The generated quasi-SC was used in an optical-coherence tomography system. High axial resolutions of 5.1 μm in air and 3.7 μm in tissue were obtained. A maximum sensitivity of 100 dB was achieved, and ultrahigh-resolution images of a hamster cheek pouch were observed.