ANALYSIS OF ULTRA-SHORT PULSE-PROPAGATION IN A FIBER NONLINEAR AMPLIFYING LOOP MIRROR

Ultra-short (60-500 fs) Pulse propagation in a nonlinear amplifying lo op mirror is compared for three kinds of single-mode fiber: standard, dispersion shifted and dispersion flattened fiber. The calculations we re done using the nonlinear Schrodinger equation model of pulse propag ation and progressively adding higher order terms, including third-ord er dispersion, self-steepening, and self-frequency shifting. It was fo und that these higher order terms have a significant impact on the per formance of the nonlinear amplifying loop mirror for pulse durations l ess than approximately 300 fs. This study has direct application to th e modeling and design of figure-eight lasers generating the shortest b andwidth limited pulses.