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arXiv · 2303.01360

Measuring spatio-temporal couplings using modal spatio-spectral wavefront retrieval

N. Weiße·J. Esslinger·S. Howard·F. M. Foerster·F. Haberstroh·L. Doyle·P. Norreys·J. Schreiber·S. Karsch·A. Doepp
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Abstract

Knowledge of spatio-temporal couplings such as pulse-front tilt or curvature is important to determine the focused intensity of high-power lasers. Common techniques to diagnose these couplings are either qualitative or require hundreds of measurements. Here we present both a new algorithm for retrieving spatio-temporal couplings, as well as novel experimental implementations. Our method is based on the expression of the spatio-spectral phase in terms of a Zernike-Taylor basis, allowing us to directly quantify the coefficients for common spatio-temporal couplings. We take advantage of this method to perform quantitative measurements using a simple experimental setup, consisting of different bandpass filters in front of a Shack-Hartmann wavefront sensor. This fast acquisition of laser couplings using narrowband filters, abbreviated FALCON, is easy and cheap to implement in existing facilities. To this end, we present a measurement of spatio-temporal couplings at the ATLAS-3000 petawatt laser using our technique.

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N. Weiße, J. Esslinger, S. Howard, F. M. Foerster, F. Haberstroh, L. Doyle, P. Norreys, J. Schreiber, S. Karsch, A. Doepp. 2023-03-02. Measuring spatio-temporal couplings using modal spatio-spectral wavefront retrieval. https://arxiv.org/abs/2303.01360

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