Ma Yunxiu, Zhu Xiushan, Yang Luyun, Tong Minghong, Norwood Robert A, Wei Huai, Chu Yingbo, Li Haiqing, Dai Nengli, Peng Jinggang, Li Jinyan, Peyghambarian Nasser
Opt Express. 2019 May 13;27(10):14487-14504. doi: 10.1364/OE.27.014487.
GHz repetition rate fundamentally mode-locked lasers have attracted great interest for a variety of scientific and practical applications. A passively mode-locked laser in all-fiber format has the advantages of high stability, maintenance-free operation, super compactness, and reliability. In this paper, we present numerical investigation on passive mode-locking of all-fiber lasers operating at repetition rates of 1-20 GHz. Our calculations show that the reflectivity of the output coupler, the small signal gain of the doped fiber, the total net cavity dispersion, and the modulation depth of the saturable absorber are the key parameters for producing stable fundamentally mode-locked pulses at GHz repetition rates in very short all-fiber linear cavities. The instabilities of GHz repetition rate fundamentally mode-locked all-fiber lasers with different parameters were calculated and analyzed. Compared to a regular MHz repetition rate mode-locked all-fiber laser, the pump power range for the mode-locking of a GHz repetition rate all-fiber laser is much larger due to the several orders of magnitude lower accumulated nonlinearity in the fiber cavity. The presented numerical study provides valuable guidance for the design and development of highly stable mode-locked all-fiber lasers operating at GHz repetition rates.
GHz重复频率的基模锁模激光器因其在各种科学和实际应用中的表现而备受关注。全光纤格式的被动锁模激光器具有高稳定性、免维护运行、超紧凑性和可靠性等优点。在本文中，我们对工作在1-20 GHz重复频率的全光纤激光器的被动锁模进行了数值研究。我们的计算表明，输出耦合器的反射率、掺杂光纤的小信号增益、总净腔色散以及饱和吸收体的调制深度是在极短的全光纤线性腔中产生GHz重复频率稳定基模锁模脉冲的关键参数。计算并分析了不同参数的GHz重复频率基模锁模全光纤激光器的不稳定性。与常规的MHz重复频率锁模全光纤激光器相比，由于光纤腔中累积的非线性低几个数量级，GHz重复频率全光纤激光器锁模所需的泵浦功率范围要大得多。本文所呈现的数值研究为设计和开发工作在GHz重复频率的高稳定性锁模全光纤激光器提供了有价值的指导。
