Intracavity Frequency Doubling Of Raman Lasers, And Coherent Anti-stokes Collinear Phase Matching Theory

Solid-state Raman lasers possess many good properties, and have important applications in various fields. Yellow laser has a wide range of applications in many fields, but it is more difficult to generate yellow coherent light than any other visible light. Recently, intracavity frequency doubling Ramam lasers has been verified to be an efficient way to produce yellow light output by experiments, and attract extensive research interests. In this paper, we deduce the normalized space-dependent rate equations of the actively and passively Q-switched intracavity frequency doubling Raman lasers, respectively. The composite variable values are estimated from the reported experimental parameters. The numerical calculations are carried out to investigate the effects of these composite variables on the performance of actively Q-switched intracavity frequency doubling yellow Raman lasers and the passively Q-switched intracavity frequency doubling Raman lasers. The theoretical results from the new rate equations of actively Q-switched intracavity frequency doubling yellow Raman lasers are compared with the experimental results, and it is shown that the theoretical study can predict the performance of this type of Raman lasers. The new theoretical models can be adopted to help the design and optimization of Q-switched intracavity frequency doubling Raman lasers.In this paper, we investigate the collinear phase-matching of the coherent anti-Stokes Raman scattering (CARS) in Raman crystals for the first time to our knowledge. The coherent anti-Stokes Raman scattering can achieve the frequency up-conversion to expand the coherent spectrum scope, and generate coherent light of important applications. Up to now, most CARS experiments adopt gas Raman media, and the beam quailty and conversion efficiency of the coherent anti-Stokes output are poor due to the CARS non-collinear phasing-matching. The anisotropic structure of crystalline Raman media can be taken advantage to achieve the CARS collinear phase-matching to obtain the coherent anti-Stokes output of good beam quality and high conversion efficiency. We study the Raman properties of YVO4, GdVO4, SrWO4, BaWO4 in detail, and caculate the collinear phase-matching angle of these Raman crystals for different polarization configurations.