Research On The Characteristics Of Fiber Laser Based On The "8" Cavity And Nanomaterials

It is an important research method in the filed of laser physics,material science,micronano technology and nanotechnology,military defense and biomedicine to generate pulse laser using mode-locked technology.All-fiber mode-locked lasers have the significant advantages over solid mode-locked laser,such as small size,insensitive to the external environment,easy integration,self-starting function,free debugging for a long time and high output stability.In the field of laser technology,we usually use some traditional mode-locked technologies to generate ultrashort pulse output in order to achieve high power output,such as nonlinear polarization rotation(NPR),nonlinear optical loop mirror(NOLM)and nonlinear amplification loop mirror(NALM).And we also by using a saturable absorber(SA)into the laser cavity to obtain ultrashort pulse output.These nanomaterials are characterized by adjustable nonlinear absorption coefficient,short time of receiving and feedback signal light,and low loss after the light passes through these materials.Hence these materials can be employed as optical absorption materials in the lasers in order to obtain high power,broadband mode-locked pulse sources.This paper mainly studies the novel methods and phenomena of passively mode-locked fiber laser,and also develops the research on some novel nanomaterials acted as SA in the application of passively mode-locked fiber laser.In this paper,the passively mode-locked fiber laser based on nonlinear optical loop mirror(NOLM)and carbon nanotubes transparent paper(CNTs/T-paper)and SnS nanosheet SA are mainly studied experimentally.The laser resonant can directly generate supercontinuum by using figure-eight fiber laser without any amplification system and special fibers.The CNTs/T-paper has a higher laser-induced damage threshold than the CNT based on polymer film and a higher stability than the free-polymer CNT film.Hence,these novel nanomaterials are expected to be used as a novel nonlinear optical SA device in the ultrashort pulsed lasers.