Highly efficient picosecond all-solid-state Raman laser at 1179 and 1227  nm on single and combined Raman lines in a BaWO4 crystal

We present a highly efficient ring-cavity all-solid-state BaWO4 Raman laser generating at both the long-shift (ν1=925 cm-1) and short-shift (ν2=332 cm-1) Raman lines under external picosecond synchronous pumping at the wavelength of 1063 nm. Very high slope efficiencies and output pulse energies of 68.8% and 103 nJ at the ν1-shifted Stokes wavelength of 1179 nm, and 38.6% and 53 nJ at the (ν1+ν2)-shifted Stokes wavelength of 1227 nm have been achieved. Self-mode locking of the (ν1+ν2)-shifted Stokes field under intracavity pumping by the ν1-shifted Stokes field allowed to realize 12-fold shortening of the 1227 nm radiation pulse down to 3 ps close to the shorter dephasing time of the ν2 Raman line at the output pulse peak power 1.5 times higher than the pump peak power.