Efficient method to improve the distribution probability of dissipative soliton and noise-like pulse in all-normal-dispersion fiber lasers

Abstract

Inspired by the chirped pulse amplification technique, herein, we show an efficient method to improve the distribution probability of dissipative soliton and noise-like pulse in all-normal-dispersion fiber lasers by using an intracavity pulse power editing (PPE) technique for the first time. The dissipative-soliton fiber laser is thus simplified into three parts: a PPE link, a saturable absorber (SA), and a spectral filter. Pulse with different peak powers can be edited in the PPE link, then undergo the positive- or reverse-saturable absorption of the SA, and finally pass through the filter. Further, just by assigning the length of single-mode fiber (SMF) at different positions in the PPE link with a fixed cavity length, four pulse patterns, including dissipative soliton (DS), DS molecules, a bound pattern of DS and noise-like pulse (NLP), and pure NLP, can be controllably produced in fiber lasers. The observed bound pattern of DS and NLP is a new addition to the pulse dynamic pattern family. It is found that the longer the SMF after the gain fiber is, the pulse will be severely broadened. This pulse can easily enter the positive-saturable absorption region of most saturated absorption curves, which will increase the probability of DS radiation; if the SMF behind the gain fiber is shorter, the pulse is not severely broadened. The pulse has a high probability of entering the reverse-saturable absorption range of most saturated absorption curves, resulting in a higher likelihood of generating NLP. In experiments, it is only necessary to increase the SMF length between the gain fiber and the isolator to build a DS fiber laser; however, to construct an NLP fiber laser, only the SMF length between the gain fiber and the isolator needs to be shortened. The experimental results agree well with the numerical predictions. The results significantly broaden the design possibilities for pulse lasers, making them much more accessible to produce specific pulse patterns.