title: Fourier domain mode-locked swept source at 1050 nm based on a tapered amplifier.
abstract: While swept source optical coherence tomography (OCT) in the 1050 nm range is promising for retinal imaging, there are certain challenges. Conventional semiconductor gain media have limited output power, and the performance of high-speed Fourier domain mode-locked (FDML) lasers suffers from chromatic dispersion in standard optical fiber. We developed a novel light source with a tapered amplifier as gain medium, and investigated the FDML performance comparing two fiber delay lines with different dispersion properties. We introduced an additional gain element into the resonator, and thereby achieved stable FDML operation, exploiting the full bandwidth of the tapered amplifier despite high dispersion. The light source operates at a repetition rate of 116 kHz with an effective average output power in excess of 30 mW. With a total sweep range of 70 nm, we achieved an axial resolution of 15 microm in air (approximately 11 microm in tissue) in OCT measurements. As our work shows, tapered amplifiers are suitable gain media for swept sources at 1050 nm with increased output power, while high gain counteracts dispersion effects in an FDML laser.
authors: DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde, Denmark. sema@fotonik.dtu.dk
authors: Sebastian
authors: S
authors: Marschall
authors: Thomas
authors: T
authors: Klein
authors: Wolfgang
authors: W
authors: Wieser
authors: Benjamin R
authors: BR
authors: Biedermann
authors: Kevin
authors: K
authors: Hsu
authors: Kim P
authors: KP
authors: Hansen
authors: Bernd
authors: B
authors: Sumpf
authors: Karl-Heinz
authors: KH
authors: Hasler
authors: Götz
authors: G
authors: Erbert
authors: Ole B
authors: OB
authors: Jensen
authors: Christian
authors: C
authors: Pedersen
authors: Robert
authors: R
authors: Huber
authors: Peter E
authors: PE
authors: Andersen
mesh_terms: D000669:Amplifiers, Electronic; D028462:Cucumis / Q000166:cytology; D005583:Fourier Analysis; D006801:Humans; D007368:Interferometry; D008027:Light; D012867:Skin / Q000166:cytology; D013057:Spectrum Analysis; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods*