Spectral broadening and compression of sub-millijoule laser pulses in hollow-core fibers filled with sulfur hexafluoride.

Spectral broadening in gas-filled hollow-core fibers is discussed for sulfur hexafluoride, a molecular gas with Raman activity. Experimental results for compressed pulses are presented for input pulses longer than the Raman period and shorter than the dephasing time at a central wavelength of 800 nm and 400 nm, respectively. For both wavelengths we compress the pulses by a factor of three and maintain a good pulse quality. The obtained results are of interest for compressing pulses generated with Yb doped lasers.