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

Abstract

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.