title: Spectrum narrowing of high power Tm: fiber laser using a volume Bragg grating.
abstract: Efficient operation of a cladding pumped high power Tm: fiber laser with a volume Bragg grating (VBG) as wavelength selective and spectrally narrowing element is reported. The laser yielded over 112 W of diffraction limited output at 1988 nm with a spectral linewidth of ~12 pm for 279 W of launched pump power, corresponding to a slope efficiency with respect to launched pump power of 43.4%. No discernable difference was observed in terms of output power and slope efficiency when using a broadband highly reflective mirror in place of the VBG.
authors.affiliation: Institute of Directed Energy Technology, College of Opto-Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Deyuan
authors.initials: D
authors.lastname: Shen
authors.forename: Dianyuan
authors.initials: D
authors.lastname: Fan
authors.forename: Qisheng
authors.initials: Q
authors.lastname: Lu