Superradiance enhancement by bad-cavity resonator

Abstract

In this work we consider the dynamics of an ensemble of two-level atoms that interact with finite-width resonator mode. The superradiant burst occurs under a wide range of parameters in such a system. However, if the initial phase distribution of dipole moments of N two-level atoms is random, not all atoms take part in the superradiant process, but only the part of them that results in the intensity of supperradiance ∼ α I N , where α < 2. In this paper we investigate the dependence of the parameter α on the resonator mode decay rate. It is shown that there is a critical value of resonator mode decay rate that divides two different regimes of superradiance. If the decay rate is lower than the critical rate, superradiance demonstrates a multi-peak character and the number of dipoles forming superradiant burst increases while α grows from 1 to 2. When the decay rate is larger than the critical value there is a single-peak superradiant regime. The delay time dependence on N changes from power to logarithmic law at the critical decay rate. The existence of the optimal value of resonator decay rate can be used for superradiance enhancement by a resonator with finite losses.

Quantifying the breakdown of the rotating-wave approximation in single-photon superradiance

“…Here we show how in our multiple-scattering formalism the validity of the RWA can be tested by comparing instead the induced inter-emitter interactions (proportional to a field propagator) with and without making the RWA. These induced interactions emerge in the implicit solution of the dynamics as described by the Lippmann-Schwinger equation (9). Without making the RWA in our quantum optical model, the propagator that emerges is the classical electromagnetic Green function [54], while here we find that within the RWA the propagator that emerges carries an error term.…”

“…The collective emission may be much faster and brighter than single-atom emission, which is called superradiance [1,2], or slower, known as subradiance [3][4][5]. Such collective effects have garnered renewed interest in nanophotonics [6,7], for nanolasers [8][9][10], precision metrology [11,12], and in quantum information processing [5,[13][14][15].…”

Microcavity-Modified Emission from Rare-Earth Ion-Based Molecular Complexes

“…(Figure b, red dots and curve). Both amplified spontaneous emission and superradiance have superlinear dependence on the pump power, although a major difference in their exponent indices could be expected: superradiance typically exhibits explicit quadratic pump power dependence ( I ∼ N 2 ), − while amplified spontaneous emission could show superlinear dependence with any exponent indices, depending on the specific carrier dynamics and electronic properties of the gain media. ,, We would like to note that although a previous theoretical study has predicted that in low quality cavities with large dissipation rates, superradiance with α < 2 could occur when the number of emitters is small ( N < 10 6 ), we expect this not to be the case in our study due to the large quantities of molecules coupled to the cavities ( N > 10 8 , estimated by assuming only a single layer of molecules covering the bottom mirror). Combining this I ∼ N 1.4 superlinear pump-power dependence of the PL intensity with the PL enhancement and spontaneous emission rate increase, we tend to ascribe the cavity-induced modifications in the PL to amplified spontaneous emission.…”

Quantifying the breakdown of the rotating-wave approximation in single-photon superradiance

“…The collective emission may be much faster and brighter than single-atom emission, which is called superradiance [1,2,3], or slower, known as subradiance [4,5,6]. Such collective effects have garnered renewed interest in nanophotonics [7,8,3], for nanolasers [9,10,11], precision metrology [12,13], and in quantum information processing [14,15,16,6].…”