Ultrahigh-speed optical coherence tomography utilizing all-optical 40 MHz swept-source

We present an ultrahigh-speed optical coherence tomography (OCT) based on an all-optical sweptsource with an A-scan rate of 40 MHz. The inertia-free swept-source, which has its output power of 41.2 mW and tuning range of 40 nm and high scan linearity in wavenumber with Pearson's correlation coefficients r of 0.9996, consists of a supercontinuum laser, an optical band-pass filter, a linearly chirped fiber Bragg grating, an erbiumdoped fiber amplifier, and two buffer stages. With sensitivity of 87 dB, high-speed OCT imaging of biological tissue in vivo is also demonstrated.