Antibunching of photons in nonlinear Raman scattering

G. S. Agarwal, Sudhanshu Shekhar Jha

M. M. Suchchinskii

Vadim A. Markel, M. I. Shtokman

We consider sationary fluctuations due to nonlinear excitation in a bichromophore, that is, in a molecule consisting of two chromophoric groups. We describe correlated fluctuations of the level populations and of the flux of flourescent photons emitted by a bichromophore. The population fluctuations are observable in experiments involving quasielastic particle scattering or Raman scattering of probe radiation. Experiments of this kind can yield information about the rate of nonradiative energy transfer. The photon correlation is characterized by antibunching and sub-Poissonian statistics and can yield information about collective excitation and nonlinear quenching.

Yu. P. Malakyan

We develop the quantum theory of stimulated hyper-Raman scattering (HRS) and discuss the quantum statistics of pump and Stokes fields. We show that the initially coherent pump field acquires a strong squeezing that exceeds the similar squeezing in other nonlinear processes also involving two-photon absorption. Stokes field statistics are analysed in detail as a function of the initial statistics of both modes. Bunching effects are shown to be amplified in the short-time region, while in asymptotics the antibunching of Stokes photons becomes dominant, which in many cases results in sub-Poissonian statistics of Stokes mode. We also find a number of correlation effects between the photons of the two modes.

Priyanka, Simranjot Kaur, Jawahar Lal

This paper aims to study the photons antibunching in the fundamental, Stokes and signal modes of CAHRS (coherent anti-Stokes hyper Raman scattering). The generalized interaction Hamiltonian was calculated for different conditions in the Heisenberg picture under short time approximation to observe photons antibunching in the fundamental, Stokes and signal modes of CAHRS. It has been found that antibunching in the fundamental field is dependent upon interaction time, photons number, and coupling strength of field. Third order photon antibunching is found to be nonclassical to a greater extent than second- and first-order photon antibunching for the identical pump photons count. It has been also observed that the effect of photon antibunching in Stokes and signal modes is less prominent than in the fundamental- mode. Furthermore, it is also found that antibunching will increase at short interaction timeswith the increase of depth of nonclassical behavior. Finally, the extent of photons antibunching peaks precisely where the second correlation function is lowest.

雅斗 小芦