title: Self-starting, self-regulating Fourier domain mode locked fiber laser for OCT imaging.
abstract: We present a Fourier domain mode locking (FDML) fiber laser with a feedback loop allowing automatic startup without a priori knowledge of the fundamental drive frequency. The feedback can also regulate the drive frequency making the source robust against environmental variations. A control system samples the energy of the light traversing the FDML cavity and uses a voltage controlled oscillator (VCO) to drive the tunable fiber Fabry-Perot filter in order to maximize that energy. We demonstrate a prototype self-starting, self-regulating FDML operating at 40 kHz with a full width tuning range of 140 nm around 1305 nm and a power output of ~40 mW. The laser starts up with no operator intervention in less than 5 seconds and exhibits improved spectral stability over a conventional FDML source. In OCT applications the source achieved over 120 dB detection sensitivity and an ~8.9-µm axial resolution.
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, MD 21205, USA.
authors.forename: Kartikeya
authors.initials: K
authors.lastname: Murari
authors.forename: Jessica
authors.initials: J
authors.lastname: Mavadia
authors.forename: Jiefeng
authors.initials: J
authors.lastname: Xi
authors.forename: Xingde
authors.initials: X
authors.lastname: Li