Nonlinear strong-absorption wave in optically bistable medium. Problem of velocity selection

Sergei E. Esipov

Irina G. Zakharova, Vyacheslav A. Trofimov

Kristel Fobelets, Kris Thielemans

In this paper we study propagation of electromagnetic waves in media with an imaginary Kerr-type nonlinearity. We show numerically that the slowly varying envelope approximation can still be used. It is proved that theoretical problems described by this type of differential equations are Hamiltonian systems. This characteristic is used to predict the variation of the electromagnetic field in the nonlinear material. Furthermore, we find a closed expression for the electromagnetic waves in a nonlinear medium with a linear absorption and an imaginary Kerr-type nonlinearity, for both a localized and a diffusive nonlinearity. Calculating the transmission probability of light through a Fabry-P\'erot structure shows that the introduction of an imaginary Kerr-type nonlinearity describes an intensity-dependent optical gain or absorption in a nonlinear medium. This system also shows bistable behavior comparable to real Kerr-type nonlinear materials. \textcopyright{} 1996 The American Physical Society.

Alberto Lencina, Pablo Vaveliuk, B. Ruiz +2 more

A theoretical analysis on wave propagation and optical properties of slabs with light-induced free charge carriers within a Fabry-Pérot framework is presented. The key of the analysis is to attack the wave propagation problem in terms of the time-averaged Poynting vector modulus within the medium through an alternative approach. This fact allows coupling the microscopic (free charge rate) and macroscopic (electromagnetic field evolution) equations self-consistently by means of the nonlinear permittivity and conductivity, which, in turn, depend on the time-averaged Poynting vector modulus. Thereby, the transmittance, reflectance, and absorptive power are derived as functions of the pump intensity and medium thickness. Bistable behavior is found at relatively high excitation intensity for positive values of the nonlinear permittivity coefficient. The bistability enhances for increasing values of such coefficient and weakens for increasing values of nonlinear photoconductivity coefficient. On the contrary, for negative nonlinear permittivity coefficient, bistability does not appear possessing these media mirrorlike behavior. Some possible applications are suggested.

Soumyodeep Dey, N. Aich, C. Chaudhuri +1 more

Surabhi Yadav, Vijay Bhatt, Aranya B. Bhattacherjee +2 more

Abstract Objective: This paper theoretically studies a hybrid optomechanical system embedded with two coupled quantum dots (CQDs) and a third-order Kerr nonlinear medium inside the cavity. The optical bistability and absorption spectrum are analyzed for the proposed system. Methods: From the Hamiltonian which describes the proposed system, a set of quantum Langevin equations are derived. Using these equations of motion, the steady-state mean field analysis is done which gives the phenomena of optical bistability. The performance of the optical switch is also analyzed in terms of gain and switching ratio. Further, the absorption spectrum of the system is derived and analyzed from the fluctuation dynamics. Results: The optical bistability has the potential to design tunable all-optical switches. The absorption spectra display peculiar characteristics of negative absorption (transparency dip). The transparency dips are found to be strongly dependent on the frequency of the mechanical resonator. The results of our investigation reveal that the proposed system can be used as an optical switch and has numerous other applications in quantum communication systems.