Generation of picosecond pulses with the wavelength 1.54 μm by two-stage compression in stimulated scattering of nanosecond Nd3+:YAG laser pulses

Cascaded compression of 8 ns pulses from an Nd³⁺:YAG laser by stimulated Brillouin scattering in CCl₄ and then by backward stimulated Raman scattering in methane at a high pressure was used to generate Stokes (λ = 1.54 μm) pulses of 20 ps duration and ~6 mJ energy at a repetition frequency of 0.5 Hz. A detailed study was made of backward stimulated Raman scattering in high-pressure methane used to compress pulses of 500 ps duration with the λ = 1.064 μm wavelength.