title: High-power linearly-polarized single-frequency thulium-doped fiber Master-Oscillator Power-Amplifier.
abstract: We report a high power narrow-linewidth source at approximately 2 microm based on a Tm-doped fiber distributed-feedback master-oscillator and three Tm fiber amplifier stages. The master-oscillator and first two amplifier stages were in-band pumped by Er,Yb fiber lasers operating at 1565 nm, and the final stage amplifier was cladding-pumped at 795 nm by two spatially-combined diode-stacks. The MOPA yielded 100 W of single frequency output at 1943 nm with a beam propagation factor (M(2)) of 1.25 and with a polarization extinction ratio of >94%. The output power was limited by thermally-induced damage in the final amplifier stage. The prospects for further power scaling are considered.
authors.affiliation: Optoelectronics Research Centre, University of Southampton, Southampton, UK.
authors.forename: L
authors.initials: L
authors.lastname: Pearson
authors.forename: J W
authors.initials: JW
authors.lastname: Kim
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Ibsen
authors.forename: J K
authors.initials: JK
authors.lastname: Sahu
authors.forename: W A
authors.initials: WA
authors.lastname: Clarkson
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D016014:Linear Models; D055096:Optical Devices; D009991:Oscillometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D013932:Thulium / Q000737:chemistry*
chemical_list: D013932:Thulium