Research On Femtosecond Fiber Laser And Supercontinuum Generation

This dissertation was focused on ultra-short pulse sources and the generation ofsupercontinuum. Various of methods and techniques about fiber lasers in labs wereexpounded. We also presented the principle of generation of supercontiuum. In thispaper we theoretically and experimentally study generating mechanism offemtosecond ultrashort pulse and supercontiuum. The main contents include:(1) We present the research significance of fiber laser and the applicationprospects of ultra-short pulse and supercontinuum. The concept, classification,characteristics, generating mechanism and technology are reviewed and summarized.(2) We experimentally study the ultra-short pulse output from an Erbium-dopedfiber laser based on Nonlinear Amplifying Loop Mirror. With the help of dispersionmanagement, the pulse duration is1.77fs, the width of spectrum is16nm, and therepetition rate is19.7MHz.(3) We experimentally study the supercontinuum output from an Erbium-dopedfiber laser based on nonlinear polarization rotation. With the help of a bidirectionalpumping configuration and the optimization of pulse duration and energy,50.8nJ,284fs ultra-short pulses with a repetition rate of2.8MHz are generated. Then the pulseis put to a piece of dispersion-shifted fiber, the spectrum covers from1540nm to1660nm.