Efficient picosecond PbWO4 and two-wavelength KGd(WO4)2 Raman lasers in the IR and visible

A mode-locked Nd:YAG laser at 1064 nm generates stimulated Raman scattering inside the laser cavity as well as in an external cavity, We optimized the output power in the external cavity arrangement using a dielectric output mirror,vith 22% transmission. The spatial beam profile, input/output energy characteristics, and temporal emission distribution were studied, Raman laser action was achieved with PbWO4 at lambda=1176 mn and with KGd(WO4)(2) at both lambda=1159 mn and lambda=1177 mm, The conversion efficiencies reach 70%, The two lines in KGW are generated separately by rotating around the crystal b axis oriented parallel to the beam direction. All Raman laser wavelengths were converted to the yellow spectral region by second harmonic generation in LBO.