Impact of pump light spatial modulation on the generation of gain-switched sub-nanosecond Ti:Sapphire laser

The Ti: Sapphire laser generation was investigated under the pumping by the spots with a different distribution of the pump fluence. We found that the characteristics obtained under pumping by the small-scale spatially modulated 532 nm light are indicative of intracavity light scattering. This scattering can be accounted for by pump light-induced optical nonuniformities in the Ti:Sapphire crystal. The scattering increases the laser angular divergence, but, at the same time, produces a coupling, required for the synchronization of the generation over the laser aperture. The appearance of the nonuniformities under the pumping is explained by well-known RIC-effect.