No abstract

We investigated the spectral behavior of a white-light continuum generated in air by 2-TW femtosecond laser pulses at 800 nm. The spectrum extends at least from 300 nm to 4.5 mum. From 1 to 1.6 mum the continuum's intensity increases strongly with the laser energy and depends on the initial chirp.

We report simultaneous measurements and ab initio calculations of the second-order nonlinear coefficients for SiC polytypes. Our measured values for χzzz (χzxx) are 18 (−4) pm/V for 4H SiC and 24 (−4) pm/V for 6H SiC. They are in good agreement with our theoretical results.