title: Quasi mode-locking of coherent feedback random fiber laser.
abstract: Mode-locking is a milestone in the history of lasers that allows the generation of short light pulses and stabilization of lasers. This phenomenon is known to occur only in standard ordered lasers for long time and until recently it is found that it also occurs in disordered random lasers formed by nanoscale particles. Here, we report the realization of a so-called quasi mode-locking of coherent feedback random fiber laser which consists of a partially disordered linear cavity formed between a point reflector and a random distributed fiber Bragg grating array with an inserted graphene saturable absorber. We show that multi-groups of regular light pulses/sub-pulses with different repetition frequencies are generated within the quasi mode-locking regime through the so-called collective resonances phenomenon in such a random fiber laser. This work may provide a platform to study mode locking as well as pulse dynamic regulation of random lasing emission of coherent feedback disordered structures and pave the way to the development of novel multi-frequency pulse fiber lasers with potentially wide frequency tuning range.
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: R
authors.initials: R
authors.lastname: Ma
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: W L
authors.initials: WL
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: X P
authors.initials: XP
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Yang
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Rao
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: B C
authors.initials: BC
authors.lastname: Yao
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: C B
authors.initials: CB
authors.lastname: Yu
authors.affiliation: Key Laboratory of Optical Fiber Sensing and Communications (Education Ministry of China), University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.
authors.forename: S F
authors.initials: SF
authors.lastname: Yu