Presentation
6 October 2023 Dispersive effects in ultrafast non-linear phenomena
Author Affiliations +
Abstract
It is a basic principle that the effect cannot come before the cause. Dispersive relations that follow from this fundamental fact have proven to be an indispensable tool in physics and engineering. They are most powerful in the domain of linear response where they are known as Kramers-Kronig relations. However when it comes to nonlinear phenomena the implications of causality are much less explored, apart from several notable exceptions. Here in this work we demonstrate how to apply the dispersive formalism to analyse the ultrafast nonlinear response in the context of the paradigmatic nonlinear Kerr effect. We find that the requirement of causality introduces a noticeable effect even under assumption that Kerr effect is mediated by quasi-instantaneous off-resonant electronic hyperpolarizability. We confirm this by experimentally measuring the time resolved Kerr dynamics in GaAs by means of a hybrid pump-probe Mach- Zehnder interferometer and demonstrate the presence of an intrinsic lagging between amplitude and phase responses as predicted by dispersive analysis. Our results describe a general property of the time-resolved nonlinear processes thereby highlighting the importance of accounting for dispersive effects in the nonlinear optical processes involving ultrashort pulses.
Conference Presentation
© (2023) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Zhanybek Alpichshev and Dusan Lorenc "Dispersive effects in ultrafast non-linear phenomena", Proc. SPIE PC12681, Ultrafast Nonlinear Imaging and Spectroscopy XI, PC1268101 (6 October 2023); https://doi.org/10.1117/12.2677180
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KEYWORDS
Ultrafast phenomena

Femtosecond phenomena

Gaussian pulse

Kerr effect

Gallium arsenide

Mach-Zehnder interferometers

Physics

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