2.04 μm harmonic noise-like pulses generation from a mode-locked fiber laser based on nonlinear pola

• 作 者: WANG Xiao-fa JIN Zeng-gao LIU Jing-hui
• 机 构: School of Optoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqin
• 出 处: 光电子快报（英文版）
• 发表日期: 2021年1期

We report the generation of harmonic noise-like mode-locked pulses in a thulium-doped fiber laser.In this laser,mode-locking can be realized through the nonlinear polarization rotation(NPR)technique.The ring cavity configura-tion uses 5 m of a Tm-doped dual-cladding fiber,as a gain medium,pumped by a 793 nm diode laser.The cavity uses a couple of polarization controllers(PCs)and polarization-dependent isolator to form a nonlinear polarization-rotating saturable absorber.By carefully adjusting of the PCs,the laser generates noise-like mode-locked pulses at the 2.04 μm band.With the increase of the pump power,the laser generates harmonics of the mode-locking fundamental repetition frequency of 6.88 MHz,from which we can obtain the second harmonic in a controlled mode.The obtained results may be useful for enhancing the understanding of the mechanism and characteristics of noise-like pulse at the 2 μm band.