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

Journal article

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.

Authors: Weisse, N; Esslinger, J; Howard, S; Foerster, FM; Haberstroh, F

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Optical Society of America
• Journal: Optics Express
• Volume: 31
• Issue: 12
• Pages: 19733-19745
• Publication date: 2023-05-30
• Acceptance date: 2023-02-23
• DOI: 10.1364/OE.483801
• EISSN: 1094-4087
• Language: English
• Keywords: FFR