We observed the filamentation of mid-infrared ultrashort laser pulses (3.9 μm, 80 fs) in molecular gases. It efficiently generates a broadband supercontinuum over two octaves in the 2.5–6 μm spectral range, with a red-shift up to 500 nm due to the Raman effect, which dominates over the blue shift induced by self-steepening and the gas ionization. As a result, the conversion efficiency into the Stokes region (4.3–6 μm) 65% is demonstrated.
© 2013 Optical Society of America
Original Manuscript: June 14, 2013
Revised Manuscript: July 11, 2013
Manuscript Accepted: July 13, 2013
Published: August 15, 2013
D. Kartashov, S. Ališauskas, A. Pugžlys, A. Voronin, A. Zheltikov, M. Petrarca, P. Béjot, J. Kasparian, J.-P. Wolf, and A. Baltuška, "Mid-infrared laser filamentation in molecular gases," Opt. Lett. 38, 3194-3197 (2013)