LOCAL-FIELD EFFECTS IN A DENSE COLLECTION OF 2-LEVEL ATOMS EMBEDDED IN A DIELECTRIC MEDIUM - INTRINSIC OPTICAL BISTABILITY ENHANCEMENT AND LOCAL COOPERATIVE EFFECTS

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 i nteraction is enhanced by the presence of the host dielectric, resulti ng in a lower threshold density and a greater hysteresis area for intr insic optical bistability. Cooperative decay terms appear that represe nt the interaction of near dipoles mediated by the absorptive componen t of the dielectric function of the host medium. These terms are part of the local response and correspond to local cooperative decay effect s.