O Seminário de Ótica da próxima terça-feira, 24 de setembro (14 horas, no Auditório do DF/UFPE) será apresentado pelo estudante Álvaro Mitchell Galvão de Melo (Departamento de Física/UFPE).

Título: Forward four-wave mixing via recoil-induced resonances

Resumo: Absorption and emission of radiation by atoms give rise to an exchange of energy and momentum between the atomic medium and the electromagnetic field due to the recoil of atoms. If the atoms are sufficiently cold, this effect can lead to the appearance of a narrow and dispersive feature, recoil-induced resonances (RIR),  in the transmission of a probe beam in a pump-probe experiment. Jointly with the existence of RIR, the prediction of a phase-conjugate signal due to a four-wave mixing (FWM) process was done. Backward FWM signals, via RIR, using cold atoms as nonlinear medium were extensively studied during the past years. In this seminar I will present a systematic study of forward four-wave mixing (FFWM) via RIR. It will be also presented a simple theoretical model that allowed us to predict the lineshapes of the observed signals and to better understand the phenomenom studied.