Abstract

For many applications in spectroscopy, imaging, and machining, ultrafast low energy pulses at a high repetition rate are required. Fiber based femtosecond lasers are promising sources, however, they are not tunable which limits their application areas. We developed a noncollinearly phase matched optical parametric amplifier (NOPA) [1] for high repetition rates that not only provides the necessary tunability but also shortens the pulses by more than a factor of 20. The NOPA is pumped by the output of a commercially available 2 MHz Ytterbium-doped fiber-oscillator / fiber-amplifier system (IMPULSE; Clark-MXR, Inc.) delivering 10 pj pulses at 1035 mn center wavelength, a spectral width of 11 mn and a compressed duration of nominally 250 fs.

© 2007 IEEE