EFFICIENT RAMAN CONVERSION OF HIGH-REPETITION-RATE, 193 NM PICOSECONDLASER-PULSES

Efficient generation of Stokes lines has been obtained in H-2, CH4, N2 , and O2 by 10 ps, 300 Hz, 193 nm laser pulses. A 60% energy conversio n efficiency was recorded for the first Stokes of H-2 and 40% in CH4. For the pressure range 1-30 atm the conversion efficiency did not chan ge with pump pulse repetition rate up to 300 Hz. The higher order Stok es observed were generated mainly by means of four wave mixing.