Photon scattering

Marco O. Lanzagorta

Peilong Hong

We perform a theoretical study on the two-photon scattering effect of a single Mie scatterer, and investigate its dependence on the rotation angle of the scatterer, and the wavelength and polarization of incident light. Different regions of the two-photon correlation map are recognized by investigating two parameters, i.e., the visibility of two-photon superposition that represents the path information of different two-photon paths, and the balance factor of the double-side single-photon scattering amplitude that indicates the possibility of the single-photon scattering process. It is shown that the two-photon scattering pattern is a result of two-photon interference from the incoherent to fully coherent regime, together with a contribution from a single-photon-like correlation. In the coherent two-photon interference region, it is found that the transition from destructive to constructive interference emerges by rotating the scatterer, as well as by changing the polarization of incident light. These results demonstrate the rich features of the two-photon scattering effect for a single Mie scatterer, and open new possibilities to explore nano scatterers for controlling two-photon interference, and their applications in communications, sensing, and imaging.

Edouard Brainis

Four-photon scattering in nonlinear waveguides is an important physical process that allows photon-pair generation in well-defined guided modes, with high rate and reasonably low noise. Most of the experiments to date used the scalar four-photon scattering process in which the pump photons and the scattered photons have the same polarization. In birefringent waveguides, vectorial four-photon scatterings are also allowed: these vectorial scattering processes involve photons with different polarizations. In this paper, the theory of four-photon scattering in nonlinear, birefringent, and dispersive fibers is developed in the framework of the quantum theory of light. The work focuses on the spectral properties and quantum correlations (including entanglement) of photon pairs generated in high-birefringence and low-birefringence fibers.

William V. Meyer, Anthony E. Smart

Yu Pan, Guofeng Zhang

Abstract We consider the inelastic scattering of few photons by a ladder-type quantum system residing in a semi-infinite waveguide. Two scenarios, namely 2-photon scattering and 3-photon scattering, are investigated. The single photons are described by continuous temporal pulse functions, according to which the exact forms of the stationary output field states can be derived. Based on the exact analysis of the nonlinear dynamics, the spectral entanglement among the output photons mediated by the ladder-type quantum system is simulated. In the 2-photon scattering case, strong correlation between the output photons can be observed if each input photon is in resonance with a transition frequency of the system. In particular, there exists a weak two-photon process for the non-resonance case, where two input photons can couple to the transition between the first and third levels of the system if a two-photon resonance condition is satisfied. In the 3-photon scattering case, the presence of an ancillary photon could significantly influence the correlation pattern. There exist two nonlinear terms, one is for 2-photon inelastic scattering and the other for 3-photon inelastic scattering, in the 3-photon output state. As a result, both two-photon and three-photon processes can be observed in the pattern of spectral entanglement.

Edward R. Pike, Sarben Sarkar, Roger Andrews