Properties of Nd3+-doped and undoped tetragonal PbWO4, NaY(WO4)2, CaWO4, and undoped monoclinic ZnWO4 and CdWO4 as laser-active and stimulated Raman scattering-active crystals

Spectroscopic, laser, and chi((3)) nonlinear optical properties of tetragonal PbWO4, NaY(WO4), CaWO4, and monoclinic CdWO4 and ZnWO4 were investigated. Particular attention was paid to Nd3+-doped and undoped PbWO4 and NaY(WO4)(2) crystals. Their absorption and luminescence intensity characteristics, including the peak cross sections of induced transitions, were determined. Pulsed and continuous-wave lasing in the two F-4(3/2) --> I-4(11/2) and F-4(3/2) --> I-4(13/2) channels was excited. For these five tungstates, highly efficient (greater than 50%) multiple Stokes generation and anti-Stokes picosecond generation were achieved. All the observed scattered laser components were identified. These results were analyzed and compared with spectroscopic data from spontaneous Raman scattering. A new crystalline Raman laser based on PbWO4 was developed for the chi((3)) conversion frequency of 1-mu m pump radiation to the first Stokes emission with efficiency up to 40%. We classify all the tungstates as promising media for lasers and neodymium-doped crystals for self-stimulated Raman scattering lasers. (C) 1998 Optical Society of America. OCIS codes: 140.3380, 140.3530, 140.3580, 140.5680, 190.5650, 299.5860, 300.6250, 300.6450.