Femtosecond pulse generation based on Kerr-type and carrier-type modelocking of Nd3+ doped fiber lasers is discussed. Special emphasis is to be payed to the startup conditions and the methods used to initiate the modelocking process.
Manfred H. Ober,
"Ultrafast Nd fiber lasers", Proc. SPIE 2377, Generation, Amplification, and Measurement of Ultrashort Laser Pulses II, (10 April 1995); doi: 10.1117/12.206401; https://doi.org/10.1117/12.206401