Abstract

Single-mode rare-earth-doped fibers^[1] are an ideal medium for the generation of ultra-short pulses. Long interaction lengths for nonlinear processes d o w a very effective exploitation of nonlinear intra-cavity pulse-shaping mechanisms and d o w to mode-lock the f d glass laser bandwidth even in the presence of dominant inhomogeneous broadening. Stable femto-second pulse generation in fiber lasers generally requires the presence of both passive frequency- and amplitude modulation to be present in the cavity^[2]. Passive frequency modulation is obtained by self-phase .modulation in the presence of overall negative group velocity dispersion (-GVD) and amplitude modulation is induced by an intra-cavity nonlinear pulse- shaping mechanism^[3].

© 1991 Optical Society of America