Coherent emission of a photon by many atoms

M. I. Riazanov

Jin Xiong, Zhi‐Ming Zhang

The idea of a mazer is put forward with particular reference to the question of the driving-induced atomic coherence, which is established by a coherent driving field. The interaction of a quantum cavity field and an ultracold V-type three-level atom in which two levels are coupled by a coherent driving field, is derived. Its general quantum theory is established and the atomic emission probability and photon statistics are calculated and analysed. It is found that the mazer based on this driving-induced atomic coherence shows new features. There is a non-vanishing probability for the atom emitting a photon in the cavity even when the resonance condition is not fulfilled (here the resonance condition means that the cavity length is an integer multiple of half the atomic de Broglie wavelength). Under the resonance condition, the atomic emission probability has two sets of resonance peaks. For a very strong coherent driving field, the emission of the atom can be forbidden. As to the photon statistics, when the driving field is not very strong, the driving-induced atomic coherence reduces the photon number fluctuations of the cavity field. The photon statistics exhibits strong sub-Poissonian behaviour. In the region considered here, it can even be sub-Poissonian for any cavity length. However, when the driving field is too strong, the sub-Poissonian property may disappear.

Mikhail Ivanovich Ryazanov

Xianshan Huang, Hailian Liu

The spontaneous emission of a three-level A-typed atom embedded in anisotropic photonic crystals with two coherent bands is investigated. The relative position of the atom is described by a position-dependent parameter θ( r 0 ), in regard as the coherence of the two bands. The spectrum of the transition in free space vacuum is discussed. The spectral center can be manipulated by the coherent parameter θ( r 0 ), and the spectral intensity can be adjusted via the atomic transition in the coherent photonic reservoir.

Vladan Vuletić, Adam T. Black, James K. Thompson

Vyacheslav I. Yukalov

A system of resonance atoms doped into a photonic bandgap material is considered in the case when the resonance transition frequency lies within the band gap. Spontaneous emission of a single atom is suppressed in this situation, which is called the light localisation. It is shown that, if the density of the doped atoms is sufficiently high, the coherent interaction between atoms can appear, resulting in the emission of a single or a series of coherent pulses by a system of atoms.