Abstract

Erbium-doped fiber lasers(EDFL) are attractive as high repetition rate(rep-rate) sources for many applications such as telecommunications and A-D converters. Actively harmonically modelocked lasers can provide high rep-rate and good noise performance[1] but even with soliton pulse shortening only produce picosecond pulses. Passively modelocked lasers can provide short pulses but usually have low rep-rate. Though passive harmonic modelocking or external TDM can increase the rep-rate of such lasers, they require extensive stabilization and/or suffer from poor timing jitter and supermode suppression. Recently we have demonstrated that by incorporating phase modulation(PM) and Additive Pulse Modelock-ing(APM) in an EDFL, 480fs transform limited pulses at 1 GHz can be produced with >60dB supermode suppression[2]. Since the noise of a regenerative PM scheme has not been measured and the modulator's effectiveness decreases with shorter pulsewidth, characterizing the noise of such a laser is important.

© 2000 IEEE