Optical bistability in a [formula omitted]-type atomic system including near dipole–dipole interaction

Juan D. Serna, Amitabh Joshi

H. J. Carmichael, P. D. Drummond, Saad S. M. Hassan +1 more

Sajeev John, Tran Quang

We discuss the nonlinear response of impurity two-level atoms in a pseudophotonic band gap (PBG) to an applied laser field. It is shown that in the case when the variance of resonant dipole-dipole interaction (RDDI) is much larger than its average value and the spontaneous emission rate, a nonequilibrium second-order phase transition occurs when the applied field strength parameter exceeds the variance of RDDI. This situation arises when the atomic density is low and the resonance frequency is near the center of a wide PBG. At this threshold the system changes from glassy phase to ferroelectric phase. In the case when the average value of RDDI is larger than its variance and spontaneous emission decay rate, this phase transition becomes first order, leading to optical bistability. This situation arises when the atomic density is high or when the photon localization length within the PBG extends over many optical wavelengths. The influence of RDDI fluctuation on bistability is discussed. These results suggest that disordered, impurity-doped, PBG materials may exhibit very low threshold switching properties. \textcopyright{} 1996 The American Physical Society.

Deb Shankar Ray

Michael E. Crenshaw, Charles M. Bowden

We investigate the effect of a linear host medium on the dynamics of a dense collection of resonant atoms. We find that near dipole-dipole interaction is enhanced by the presence of the host dielectric, resulting in a lower threshold density and a greater hysteresis area for intrinsic optical bistability. Cooperative decay terms appear that represent the interaction of near dipoles mediated by the absorptive component of the dielectric function of the host medium. These terms are part of the local response and correspond to local cooperative decay effects. \textcopyright{} 1996 The American Physical Society.

Y. Ben-Aryeh, Charles M. Bowden

Atomic cooperative effects in mirrorless (intrinsic) optical bistability (MOB) have been treated, so far, either by assuming a small volume with dimensions smaller than a wavelength1,2, or by assuming a system with a small number of atoms3. In the present work we discuss MOB based upon cooperative effects among atoms in a system consisting of many two-level atoms, considering explicitly the spacial dependence of the coherent dipole-dipole interactions.