Coherent-transient amplification of polarization changes under conditions of two-photon interaction

Ashat M. Basharov, Andrei I. Maimistov, Edward A. Manykin

A. Zh. Muradyan, L. Petrosyan

A change in the polarization of an ultrashort light pulse is induced by a strong polarized pulse when the two pulses interact with three-level atoms in a gaseous medium with arbitrary values of the momentum. An analysis is made of the possibility of increasing the output signal (i.e., the amplitude of Cartesian component of a probe wave rotated by 90°) by modulation of the input wave phase in accordance with oscillations of a coherent-transient response of the gaseous medium.

Si-Cong Tian, Cunzhu Tong, Ren-Gang Wan +7 more

We investigate the effects of spontaneously generated coherence (SGC) on both the steady and transient gain properties in a four-level inverted-Y-type atomic system in the presence of a weak probe, two strong coherent fields, and an incoherent pump. For the steady process, we find that the inversionless gain mainly origins from SGC. In particular, we can modulate the inversionless gain by changing the relative phase between the two fields. Moreover, the amplitude of the gain peak can be enhanced and the additional gain peak can appear by changing the detuning of the coupling field. As for the transient process, the transient gain properties can also be dramatically affected by the SGC. Compared to the case without SGC, the transient gain can be greatly enhanced with completely eliminated transient absorption by choosing the proper relative phase between the two fields. And the inverted-Y-type system with SGC can be simulated in both atomic and semiconductor quantum well systems avoiding the conditions of SGC.

Ashat M. Basharov, V. I. Malmistov, Edward A. Manykin

Lorenzo M. Narducci, Lambros G. Johnson, E. J. Seibert +1 more

Anshou Zheng, Jiahua Li, Zhiming Zhan +1 more

We investigate the influence of the vacuum-induced coherence on one- and two-photon absorption of the transient process in a four-level Y-type atomic system. We find that the one- and two-photon transient absorption and amplification properties are quite sensitive to the vacuum-induced coherence. It is also shown that the one- and two-photon absorption spectra of the transient process can be dramatically affected by modulating the relative phase of the applied fields. By appropriately choosing the relative phase, the amplification of the probe field can be achieved.