Optical limiting via spontaneously generated coherence

Abstract

We investigate the reverse saturable absorption (RSA) and optical limiting (OL) in a three-level V-type quantum system considering the effect of the spontaneously generated coherence (SGC). It is shown that in the absence of the SGC effect, the saturable absorption (SA) is dominant in the system. By taking into account the SGC effect, we prove that the SA dramatically switches to the RSA. Moreover, it is demonstrated that the OL threshold and OL efficiency can be controlled by the SGC effect. In addition, we show that the applied field properties such as detuning can modify the SGC-induced optical limiter efficiency. It is also shown an increase in the atomic density and length of the medium makes the optical limiter more efficient. The analytical calculation shows that the Kerr nonlinearity caused by the SGC effect is the main mechanism of the system evolution. Finally, the theoretical Z-scan experiment is presented to confirm the obtained results. Our proposed scheme can be useful to design controllable atomic optical limiters for optical devices with different sensitivities.