GENERATION OF PICOSECOND PULSES WITH THE WAVELENGTH 1.54 MU-M BY 2-STAGE COMPRESSION IN STIMULATED SCATTERING OF NANOSECOND ND3-PULSES(YAG LASER)

Cascaded compression of 8 ns pulses from an Nd3+:YAG laser by stimulat ed Brillouin scattering in CCl4 and then by backward stimulated Raman scattering in methane at a high pressure was used to generate Stokes ( lambda = 1.54 mu m) pulses of 20 ps duration and similar to 6 mJ energ y at a repetition frequency of 0.5 Hz. A detailed study was made of ba ckward stimulated Raman scattering in high-pressure methane used to co mpress pulses of 500 ps duration with the lambda = 1.064 mu m waveleng th.