Tunable 1.6-2 μm near infrared few-cycle pulse generation by filamentation

We present results on tunable few-cycle laser pulses generated in the near infrared region obtained by filamentation in a krypton cell combined with group velocity dispersion compensation in fused silica. We obtain a spectral broadening of a factor similar to 2-3 over the entire spectral domain studied. The central wavelength is tuned from 1.6 mu m to 2 mu m via an optical parametric amplification source. In optimum experimental conditions, where the input central wavelength is set to 1.7 mu m; 1.8 mu m, and 1.9 mu m, the incident power to the gas cell exceeded the critical power of Krypton by a factor of similar to 4 and the achieved spectral broadening covered similar to 300 nm. Using group velocity compensation in bulk fused silica, we obtain near infrared output pulses as short as 2-3 optical cycles with 200 mu J energy per pulse. This near infrared filamentation tunable few-cycle pulse source is an important achievement for strong field physics applications such as attoscience, where wavelength scaling has an important effect. (C) 2013 Author(s).