Despite the wide applications for high-repetition-rate mode-locked fiber lasers, challenges persist in shortening the cavity length and coupling the fiber collimators for most existing techniques. Here, we introduce a novel collimator alignment method and demonstrate an all-polarization-maintaining erbium-doped fiber laser that contains a nonlinear amplifying loop mirror with a repetition rate of 213 MHz. Compared to the conventional method, we achieve in-situ alignment of the collimators in a simplified two-step process. Besides, through a comparison of the spectra from the output ports of the laser, we assess their quality and establish the spectral evolution relationships among these ports. It is found that, in addition to the widely believed large nonlinear effects, spectral interference also plays a significant role in spectral distortion. Moreover, a transition between different stability states is observed from the power variation of the single pulse.
High-precision passive stabilization of repetition rate for a mode-locked fiber laser based on optical pulse injection
East China Normal University（华东师范大学）；University of Shanghai for Science and Technology（上海理工大学）；Chongqing Institute of East China Normal University（华东师范大学重庆研究院）；Jinan Institute of Quantum Technology（济南量子技术研究院）；Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）
Watt-level all polarization-maintaining femtosecond fiber laser source at 1100 nm for multicolor two-photon fluorescence excitation of fluorescent proteins
Bottle microresonator broadband and low repetition rate frequency comb generator
我们提出了一种新型的宽带和低重复频率的频率梳发生器，它具有细长的和纳米尺度的浅光学瓶微谐振器在光纤的表面创建的形状。该谐振器的宽带方位本征频率序列的自由谱范围（FSR）是稠密和窄带轴向序列的FSR的精确倍数。微谐振器的有效半径变化接近于具有大于或等于λ/2 pi * n 0的纳米级高度的抛物线（这里λ是特征辐射波长，n 0是微谐振器材料的折射率）。总的来说，微谐振器具有宽带、小FSR和精确等距的光谱，便于产生宽带和低重复率的光学频率梳。它示出，这种梳可以通过用CW激光器泵浦，该辐射频率匹配的微谐振器的单个轴向本征频率，或者，可替代地，通过用锁模激光器泵浦，它产生一个窄带低重复率梳匹配一系列等距的轴向本征频率位于相邻的方位角本征频率之间。
