High power tunable femtosecond source based on amplification in Tm fiber

High power tunable femtosecond pulses at 1.8-2.1 /spl mu/m and frequency doubled to 900-1050 nm are useful for many applications, including micromachining, spectroscopy, nonlinear frequency conversion, THz generation and two-photon microscopy. Fiber-based sources have the benefits of robustness, compactness and reduced cost compared to their bulk counterparts. Here amplification of a Raman shifted Er fiber laser in a large mode area (LMA) Tm fiber producing femtosecond pulses without a pulse compressor.