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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

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Spatial Beam Self-Cleaning in Second-Harmonic Generation.

Krupa K K Fona R R Tonello A A Labruyère A A Shalaby B M BM Wabnitz S S Baronio F F Aceves A B AB Millot G G Couderc V V

Scientific reports 20200429 1

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 b ...[more]

PMID: 32350305

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