Optical Bistability in a Controllable Giant Self-Kerr Nonlinear Gaseous Medium under Electromagnetically Induced Transparency and Doppler Broadening

Phuong Le Thi Minh,Khoa Dinh Xuan,Bang Nguyen Huy,Doai Le Van

doi:10.1155/2018/7260960

Phuong Le Thi Minh, Khoa Dinh Xuan + Show 2 more

Open Access

https://doi.org/10.1155/2018/7260960

Copy DOI

Abstract

We study optical bistability (OB) in a controllable giant self-Kerr nonlinear atomic gaseous medium placed in a unidirectional ring cavity. The medium is coherently excited by strong controlling field and a weak probe laser field under electromagnetically induced transparency (EIT) and Doppler broadening. In a weak field limit of the probe light, an analytic OB equation for the probe light field is derived as an analytic function of parameters of the controlling field and temperature of the medium. It is shown that OB characters can be manipulated with the parameters due to the controllable properties of the self-Kerr nonlinearity. Furthermore, enhancement of the Kerr nonlinearity reduces the switching intensity threshold and width of the OB.

Highlights

The optical bistability (OB) is one of the most interesting fields of research in nonlinear optics because it has a large number of potential applications in both optical sciences and photonic technology, for example, all-optical switches, all-optical memories, optical transistors, and all-optical logic gates [1,2,3]
Doai et al [13] have developed an analytical model of electromagnetically induced transparency (EIT) enhanced self-Kerr nonlinearity with controllable parameters of a light field and temperature of atomic sample which is in good agreement with the experimental observations [12]
With the growth of this interest, in this work, we studied controlling OB of the three-level EIT atomic gaseous medium under presence of giant self-Kerr nonlinearity and Doppler broadening by using an analytic method

Summary

Introduction

The OB is one of the most interesting fields of research in nonlinear optics because it has a large number of potential applications in both optical sciences and photonic technology, for example, all-optical switches, all-optical memories, optical transistors, and all-optical logic gates [1,2,3]. The magnitude, slop, and sign of the Kerr nonlinear coefficient can be controlled by tuning frequency and/or intensity of the coupling light or by changing temperature of the medium. Such controllable giant Kerr nonlinear media are used for controllable optical bistability [14], generating four-wave mixing beams [15] which exploit new ways in designing devices for optical switching in optical communication and all-optical signal processing. With the growth of this interest, in this work, we studied controlling OB of the three-level EIT atomic gaseous medium under presence of giant self-Kerr nonlinearity and Doppler broadening by using an analytic method. The influences of Doppler broadening and the controlling light on switching intensity thresholds and width of the OB are investigated

The Mater Equation of OB

Analysis of OB

Conclusion