Fiber Laser Research from the late 80 's had already begun, because it can generate Ultrashort pulses, has a very broad application prospects, countries around the world showed great enthusiasm for fiber laser. Compared with other types of lasers, fiber lasers with high reliability, simple structure, low price, high conversion efficiency advantages. 

Domestic research in this area is relatively early, both theoretically and experimentally, many research results have been made. However, compared with foreign countries, there is still a large gap. Especially for high performance fiber laser research is relatively small, practical work done is far from enough, the effect is not very ideal. Therefore, it is necessary to further strengthen the study of passively mode-locked fiber lasers.