Efficient Raman conversion of high repetition rate, 193 nm picosecond laser pulses

Abstract
Efficient generation of Stokes lines has been obtained in H2, CH4, N2, and O2 by 10 ps, 300 Hz, 193 nm laser pulses. A 60% energy conversion efficiency was recorded for the first Stokes of H2 and 40% in CH4. For the pressure range 1–30 atm the conversion efficiency did not change with pump pulse repetition rate up to 300 Hz. The higher order Stokes observed were generated mainly by means of four wave mixing.