High-average-output mode-locked figure-eight all-fibre Yb master oscillator

摘要

The present work summarises the results of studies of an all-fibre figure-eight mode-locked Yb fibre master oscillator based on non-linear amplifying loop mirror with the average output power exceeding 1 W. We show that the studied resonator configuration can generate clusters of 200-femtosecond pulses at repetition rate of 25 MHz with the cluster envelope duration of around 20 ps. We demonstrate pulse properties of two typical mode-locked generation regimes with widely different output pulse spectra and discuss specific features of pulses exiting the laser cavity via two fibre ports. We also provide analytical estimations and numerical modelling which agree well with experimental measurements.