Discretely swept optical-frequency domain imaging toward high-resolution, high-speed, high-sensitivity and long-depth-range

We have been developing a unique discretely swept optical frequency domain imaging (OFDI) using superstructured-grating distributed Bragg reflector (SSG-DBR) lasers. To increase resolution, four SSG-DBR lasers are being developed to obtain spectral coverage of 160 nm in total. To increase speed of D-OFDI imaging, simultaneous scanning of multiple sources with a parallel OFDI system and unique transversal scanning D-OFDI have been demonstrated. Introduction of an optical amplifier can increase sensitivity beyond the conventional shot noise limit. A deep 12 mm depth range has been demonstrated with the wavelength interval of 0.05 nm.