All-fiber generation of few-cycle pulses at 1950 nm by triple-stage compression of a Thulium-doped laser system

The positively pre-chirped pulses from a Thulium-doped fiber-laser system are compressed in a cascade of three fibers with increasing nonlinearity. Using chirped pulse amplification and a large mode area fiber for compression after the main amplifier we achieve a pulse duration of 110 fs. In two additional nonlinear stages the pulses are compressed down to 27 fs at an average power of 450mW, while maintaining an all-fiber configuration.