Multiwave coherent interaction and nonlinear frequency shift

Pierre Meystre

Iam Choon Khoo, Ping Zhou

We present a detailed quantitative theory of transient multiwave mixing effects in a nonlinear medium produced by two incident coherent laser beams. Our theory accounts for all the relevant parameters such as laser pulse widths, medium response times, nonlinearities, interaction length, intensities, beam ratio, phase-modulation effects, losses, side diffractions, and explicitly shows how the dynamics and the multiwave mixing processes are interrelated with these parameters. The crucial role played by the diffracted beams and the time-dependent phase shifts among the beams and the interplay among the various intensity and index gratings are explicitly evaluated. In particular, the gain experienced by a weak incident probe beam via these mixing effects from the incident strong pump beam is investigated as a function of the aforementioned parameters.

Hermann Haken, H. Sauermann

Zhaoyang Zhang, Ji Guo, Bingling Gu +4 more

We study the parametric amplification of electromagnetically induced transparency-assisted Rydberg six- and eight-wave mixing signals through a cascaded nonlinear optical process in a hot rubidium atomic ensemble both theoretically and experimentally. The shift of the resonant frequency (induced by the Rydberg–Rydberg interaction) of parametrically amplified six-wave mixing signal is observed. Moreover, the interplays between the dressing effects and Rydberg–Rydberg interactions in parametrically amplified multiwave mixing signals are investigated. The linear amplification of Rydberg multiwave mixing processes with multichannel nature acts against the suppression caused by Rydberg–Rydberg interaction and dressing effect.

Michael S. Feld, Vladilen S Letokhov

Joshua Mornhinweg, Maike Halbhuber, Cristiano Ciuti +3 more

We investigate the nonlinearities of custom-tailored ultrastrongly light-matter coupled states by driving them with both the vacuum electromagnetic field and strong coherent THz waveforms. In this novel regime, where both the Rabi frequency induced by the coherent field and the vacuum Rabi frequency set by the cavity field are on the order of the carrier frequency of light, we observe strong subcycle pump-probe and multiwave mixing nonlinearities and nonlinear polariton correlations, violating the normal-mode approximation. Such custom-cut nonlinearities of hybridized excitations set the stage for nonlinear optical control of deep-strong coupling, exploring quantum phase transitions or nonclassical light sources.