title: Direct generation of 2  W average-power and 232  nJ picosecond pulses from an ultra-simple Yb-doped double-clad fiber laser.
abstract: We report the generation of 2.06 W average-power and 232 nJ picosecond mode-locked pulses directly from an ultra-simple Yb-doped fiber laser. A section of Yb-doped double-clad fiber pumped by a 976 nm laser diode provides the large gain, and the linear cavity is simply formed by a 1064 nm highly reflective fiber Bragg grating and a fiber loop mirror (FLM) using a 5/95 optical coupler. The asymmetric FLM not only acts as the output mirror for providing ∼20% optical feedback, but also equivalently behaves as a nonlinear optical loop mirror (NOLM) to initiate the mode-locking operation in this cavity. Stable mode-locking is therefore achieved over a pump power of 3.76 W. The mode-locked pulses show the dissipative soliton resonance (DSR), which has the pulse duration of 695 ps to ∼1  ns, and the almost unchanged peak power of ∼200  W as increasing the pump power. In particular, this laser can emit 232 nJ high-energy DSR pulses with an average output power of >2  W. This is, to the best of our knowledge, the first demonstration of such an ultra-simple, mode-locked fiber laser that enables watt-level, high energy, picosecond DSR pulses.
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Huang
authors.forename: Zhengqian
authors.initials: Z
authors.lastname: Luo
authors.forename: Fengfu
authors.initials: F
authors.lastname: Xiong
authors.forename: Yingyue
authors.initials: Y
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Zhong
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Cai
authors.forename: Huiying
authors.initials: H
authors.lastname: Xu
authors.forename: Hongyan
authors.initials: H
authors.lastname: Fu