Supermode noise suppression in a harmonically modelockedfibre laser by selfphase modulation and spectral filtering

Abstract

Harmonically modelocked fibre lasers suffer from supermode noise because the slow gain relaxation time cannot equalise the individual pulse energies. The authors show that the combination of selfphase modulation and spectral filtering provides a fast intensity dependent loss in the cavity, which equalises the pulse energies and completely suppresses supermode competition.