Spatial Beam Self-Cleaning in Second-Harmonic Generation.

ABSTRACT: We experimentally demonstrate the spatial self-cleaning of a highly multimode optical beam, in the process of second-harmonic generation in a quadratic nonlinear potassium titanyl phosphate crystal. As the beam energy grows larger, the output beam from the crystal evolves from a highly speckled intensity pattern into a single, bell-shaped spot, sitting on a low energy background. We demonstrate that quadratic beam cleanup is accompanied by significant self-focusing of the fundamental beam, for both positive and negative signs of the linear phase mismatch close to the phase-matching condition.

SUBMITTER: Krupa K 

PROVIDER: S-EPMC7190728 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature