Simulation Studies On Pulses Transmission In A Novel Fiber Amplification System

Because of the application of Ultra-short pulse technology is very wide,it has been one of the most hot spots which a lot of people focus on. As higher energy and shorter width being persued,all fiber system is also gradually taking place of the solid laser and amplifier. While studies on Ultra-short pulse system come to deeper, an effect named"self-similar"is catching people's attention due to its excellent characteristics. It is able to resist the pulse breaking and make the pulse evolve parabolically with strictly linear chirp. This could let us get shorter pulse than the input through compressor's dechirping. The subject is also part of the National Natural Science Foundation project "New hybrid waveguide device design and fabrication for THz emitters" (Grant No.: 60578022)The self-similar pulse theoretical model is introduced in this paper. The influence factors on the evolution of self-similar pulse are analyzed in the gain fiber like stimulated Raman scattering, finite gain bandwidth limitation, gain distribution phenomenon and etc. A parameter design theory which could guide the building of a self-similar EDFA system has been gotten through analysis of these factors and a new amplification system with spectrum management has been rose up.The main work is summarized as follows:1. We introduce the development of ultra-short pulse technology. And after comparing the characteristics of different amplification systems we focus on the features of self-similar amplification system.2. The self-similar pulse theoretical models based on NLSE and GLE are described in this paper. The asymptotic solutions form both models are also obtained and analysed.3. We detailedly discussed the influence factors on the evolution of self-similar pulse in the gain fiber, consided all the factors together and attempted to avoid them or reduce them from system building and parameter design aspects.4. For improving the pulse magnification and compression efficiency further we point out a new amplification system with spectrum management and simulate the function of this system.Finally we get the output with single pulse energy of 28.14nJ and compressed pulses of width 62fs, average power 562.8mW.