Enhancement of self-Kerr nonlinearity via electromagnetically induced transparency in a five-level cascade system: an analytical approach

Abstract

We propose to use a five-level cascade system to enhance self-Kerr nonlinearity under an electromagnetically induced transparency (EIT) condition. Using density-matrix theory, an expression of the self-Kerr nonlinear coefficient for a weak probe light is derived. Variations of the self-Kerr coefficient with respect to the frequency and intensity of a strong coupling light are investigated. The Kerr nonlinearity is basically modified and enhanced greatly in the spectral regions corresponding to EIT transparent windows. Furthermore, the sign, slope, and magnitude of the self-Kerr coefficient can be controlled with the frequency and intensity of the coupling light. Such a controllable Kerr nonlinearity can find interesting applications in optoelectronic devices working with low light intensity at multiple frequencies.

Phase-sensitive Kerr nonlinearity for closed-loop quantum systems

“…Electromagnetically induced transparency also has many notable applications in quantum and nonlinear optics such as multiwave mixing [8][9][10], optical bistability [11,12], optical solitons [13][14][15][16][17], and Kerr nonlinearity [18]. Many proposals have been suggested both theoretically and experimentally for achieving enhanced Kerr nonlinearity accompanied by negligible absorption in three-and four-level atomic systems [19][20][21][22][23][24][25][26]. Wang et al [19] studied experimentally the enhanced Kerr nonlinear coefficient in a three-level -type atomic system for various powers of the coupling beam.…”

“…All of these studies have dealt with the three-and four-level atomic systems. More recently, Khoa et al [26] investigated theoretically the possibility of obtaining an enhanced self-Kerr-nonlinearity under the EIT condition for a five-level cascade system. They also made a comparison between the behavior of self-Kerrnonlinearity for such a five-level atomic system with that of four-and three-level cascade systems and observed the same magnitude of the self-Kerr-nonlinear coefficient among the three systems.…”

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

“…The advent of EIT [4] offers coherent media of vanished resonant absorption [5][6][7][8] and controllable giant Kerr nonlinearity [9][10][11]. Wang et al performed a direct measurement of self-Kerr nonlinear coefficient in a three-level lambda EIT medium in the presence of Doppler broadening by using a cavity scanning technique.…”

Polarized dependence of nonlinear susceptibility in a single layer graphene system in infrared region

“…In nonlinear optics, due to significant role of Kerr nonlinearity in some important phenomena [26,27], it is favoraitable to have giant Kerr nonlinearity in low light intensities [28]. Recently it has been shown that the giant enhanced Kerr nonlinearity in multi-level atomic systems with zero linear absorption can be possible by different mechanisms [29][30][31][32][33][34][35][36][37][38]. Niu et al investigated giant Kerr nonlinearity via double dark resonances in a four-level atomic system [35].…”