Intrinsic optical bistability in Kerr ferroelectric materials
School of Physics, Universiti Sains Malaysia, 118000 USM, Penang, Malaysia
Corresponding author: a email@example.com
Revised: 19 April 2008
Published online: 20 June 2008
In this paper we investigate the intrinsic optical bistability (IOB) in a ferroelectric (FE) single layer using an alternative analysis. The FE material is considered to have an intensity-dependent refractive index where the third order nonlinear susceptibility χ(3) acts like Kerr coefficient. The nonlinear response of the FE medium is modeled using the Landau-Khalatnikov (LK) dynamical equation with the nonlinear anharmonic potential obtained from the Landau-Devonshire free energy expressed in terms of polarization. Within a single frequency approximation, the electromagnetic wave equation is written in terms of the polarization P rather than the electric field E as the dependent variable. With the application of the nonlinear boundary conditions we have derived expressions for both reflectance and transmittance as a function of the electric field incident amplitude, polarization and other material parameters. The formalism proves to be more suitable for FE materials since most of these materials have highly linear and nonlinear coefficients especially when the operating frequency is in the resonance region. The effects of thickness, operating frequency and temperature on BaTiO3 single film are investigated theoretically. The results presented here agree in principle with the recent experimental observations of intrinsic OB in BaTiO3 monocrystal and other FE photorefractive materials.
PACS: 78.20.Bh – Theory, models, and numerical simulation / 78.20.Ci – Optical constants / 42.65.Pc – Optical bistability, multistability, and switching, including local field effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008