title: Raman-pumped Fourier-domain mode-locked laser: analysis of operation and application for optical coherence tomography.
abstract: We demonstrate a Raman-pumped Fourier-domain mode-locked (FDML) fiber laser and optical coherence tomography imaging with this source. The wavelength sweep range of only 30 nm centered around 1550 nm results in limited axial resolution, hence a nonbiological sample is imaged. An output power of 1.9 mW was achieved at a sweep rate of 66 kHz and a maximum ranging depth of ~2.5 cm. Roll-off characteristics are found to be similar to FDML lasers with semiconductor optical amplifiers as gain media. The application of Raman gain also enables unperturbed cavity ring-down experiments in FDML lasers for the first time, providing direct access to the photon lifetime in the laser cavity. Good agreement with nonswept cw operation is proof of the stationary operation of FDML lasers.
authors.affiliation: Lehrstuhl für BioMolekulare Optik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Oettingenstrasse 67, 80538 Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Klein
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wieser
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Biedermann
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Eigenwillig
authors.forename: Gesa
authors.initials: G
authors.lastname: Palte
authors.forename: Robert
authors.initials: R
authors.lastname: Huber
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005583:Fourier Analysis; D007089:Image Enhancement / Q000379:methods*; D007834:Lasers; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*