Conventional and Unconventional Photon Statistics

Abstract

The photon statistics emitted by a large variety of light‐matter systems under weak coherent driving can be understood, to lowest order in the driving, in the framework of an admixture of (or interference between) a squeezed state and a coherent state, with the resulting state accounting for all bunching and antibunching features. One can further identify two mechanisms that produce resonances for the photon correlations: i) conventional photon blockade describes cases that involve a particular quantum level or set of levels in the excitation/emission processes with interferences occurring to all orders in the photon numbers, while ii) unconventional photon blockade describes cases where the driving laser is far from resonance with any level and the interference occurs for a particular number of photons only, yielding stronger correlations but only for a definite number of photons. Such an understanding and classification allows for a comprehensive and transparent description of the photon statistics from a wide range of disparate systems, where optimum conditions for various types of photon correlations can be found and realized.

Single-photon blockade in quasichiral atom–photon interaction: simultaneous high purity and high efficiency

“…In the above discussion, we mainly focus on the effect of the coupling strength between the microcavity and the plasmonic mode (G 1 ) and the induced phase (φ) on the intensity I c and the second-order correlation function g (2) c (0). We further investigate the influence of the system decays and the coupling strength between the microcavity and the QE, which turn out to be crucial in the photon blockade effect [10].…”

“…Another unconventional scheme is to induce the destructive interference between all possible transition pathways of a target n-photon state, then the n − 1 photon blockade can occur [7][8][9]. However, two existing mechanisms of photon blockades, the conventional photon blockade (CPB) and the unconventional photon blockades (UPBs), both have obvious drawbacks [10]: CPB requires the sufficiently strong atom-cavity coupling to have good performance, while the efficiency of UPB is low and its delayed two-photon correlation g (2) (τ ) generally manifests fast oscillations. These hinder the practical applications of photon blockades.…”

Photon Statistics of Filtered Resonance Fluorescence

“…In experimental quantum optics, spectral filtering around the zero phonon line (ZPL) of a TLE is widely employed to remove unwanted backgrounds from the driving laser [1,3], other transitions [13], or phonon sidebands [13][14][15], improving the measured single photon purity and indistinguishability. Considering only indistinguishability, reducing the filter bandwidth always gives an improvement (at the cost of efficiency) as more background is removed [16].However,as the filter bandwidth approaches the natural linewidth (γ)o f the ZPL, theory predicts strongly modified photon statistics in both weak (coherent scattering) [12,17] and strong (Mollow triplet) [18] driving regimes, an effect generally overlooked in experiments to date. Here, we experimentally verify these predictions, combining our results with a theoretical model to develop a thorough understanding of the complex photon statistics associated with spectrally filtered resonance fluorescence.…”

Nonclassical polariton phenomena in a triple-micropillar system

“…So that, the appearance of two photons at the same frequency is unlikely in the system (but becomes possible in the presence of the dissipation-induced broadening). This is an effect of photon blockade [5] [7,[9][10][11] which allows for converting a coherent laser light into a stream of individual photons prepaired in the Fock state [12]. Typically, this phenomenon occurs in the low-dimensional systems where strong quantization decouples ground state from the higher energy levels.…”