Polarisation dependence of photon antibunching phenomena involving light propagation in isotropic media

By the method of “short optical paths”, the dynamics of photon antibunching is shown to depend on the polarisation state of the photons and their two-photon absorption in an isotropic medium. In the case of self-induced optical birefringence, a change in helicity of the elliptically polarized beam or a change in sign of the angle between the large semi-axis of the ellipse and the analyzer causes a reversal of antibunching into bunching. Linear and circular polarisation of the photons are discussed as well for antibunching related with two-photon absorption, defined by the imaginary part of the molecular hyperpolarizability tensor.