Submicrojoule femtosecond erbium-doped fibre laser for the generation of dispersive waves at submicron wavelengths

We have demonstrated a femtosecond erbium-doped fibre laser system built in the master oscillator/power amplifier (MOPA) approach. The final amplifier stage utilises a specially designed large mode area active fibre cladding-pumped by multimode laser diodes. The system is capable of generating submicrojoule pulses at a wavelength near 1.6 mu m. We have obtained 530-fs pulses with an energy of 400 nJ. The output of the system can be converted to wavelengths shorter than 1 mm through the generation of dispersive waves in passive nonlinear fibre. We have obtained ultra-short 7-nJ pulses with a spectral width of similar to 100 nm and a centre wavelength of 0.9 mu m, which can be used as a seed signal in parametric amplifiers in designing petawatt laser systems.