Transient gratings in a nonlinear medium

Masaki Aihara

Daniel A. Erwin, Tomasz P. Jannson

Analysis is made of transient-grating reflection from a split- polarization device based on a Kerr medium with and without absorption. It is found that strong grating reflection, hence attenuation of high- intensity incident pulsed radiation, can occur when absorption is present.

Boris A. Malomed

Iam Choon Khoo, Ping Zhou, Liang Yu +1 more

The dynamics of the transient thermal-grating-mediated probe-beam amplification effect in a nematic liquid crystal film is studied with the use of millisecond laser pulses. These experimental observations and the accompanying transient multiwave mixing analysis show that peak probe gain can occur at various locations within the grating decay time; the higher the induced index change, the sooner will peak gain occur.>

Alexander A. Zabolotskii

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.