Signature of strong atom-cavity interaction on critical coupling

We study a critically coupled cavity doped with resonant atoms with metamaterial slabs as mirrors. We show how resonant atom-cavity interaction can lead to a splitting of the critical coupling dip. The results are explained in terms of the frequency and lifetime splitting of the coupled system.Comment: 8 pages, 5 figure

Gap solitons with null-scattering

We study excitation of gap solitons under the conditions of coherent perfect absorption (CPA). Our system consists of a symmetric periodic structure with alternating Kerr nonlinear and linear layers, illuminated from both the ends. We show near-total transfer of incident light energy into the gap solitons resulting in null-scattering. We also report on the nonlinear super-scattering (SS) states. Both the CPA and the SS states are shown to be characterized by typical field distributions. Both the exact and the approximate results (based on nonlinear characteristic matrix method) are presented, which show good agreement

Two photon quantum interference in plasmonics - Theory and Applications

We report perfect two photon quantum interference with near-unity visibility in a resonant tunneling plasmonic structure in folded Kretschmann geometry. This is despite absorption-induced loss of unitarity in plasmonic systems. The effect is traced to perfect destructive interference between the squares of amplitude reflection and transmission coefficients. We further highlight yet another remarkable potential of coincidence measurements as a probe with better resolution as compared to standard spectroscopic techniques. The finer features show up in both angle resolved and frequency resolved studies.Comment: 5 pages, 6 figure

Giant Radiative Interactions Among Distant Atoms

We examine the feasibility of enhancing the fundamental radiative interactions between distant atoms. We present general arguments for producing enhancement. In particular, we show how giant dipole-dipole interaction can be produced by considering dipoles placed close to micron sized silica spheres. The giant interaction arises as the whispering gallery modes can resonantly couple the dipoles.Comment: 4 figures included in the postscript file, to appear in "Current trens in Atomic and Molecular Physics", edited by R. Srivastava (Phoenix publishing House, New Delhi, India, 2001

Cavity controlled spectral singularity

We study theoretically a PT-symmetric saturable balanced gain-loss system in a ring cavity configuration. The saturable gain and loss are modeled by two-level medium with or without population inversion. We show that the specifics of the spectral singularity can be fully controlled by the cavity and the atomic detuning parameters. The theory is based on the mean-field approximation as in standard theory of optical bistability. Further, in the linear regime we demonstrate the regularization of the singularity in detuned systems, while larger input power levels are shown to be adequate to limit the infinite growth in absence of detunin