Counter-polarized single-photon generation from the auxiliary cavity of a weakly nonlinear photonic molecule

We propose a scheme for the resonant generation of counter-polarized single photons in double asymmetric cavities with a small Kerr optical nonlinearity (as that created by a semiconductor quantum well) compared to the mode broadening. Due to the interplay between spatial intercavity tunneling and polarization coupling, by weakly exciting with circularly polarized light one of the cavities, we predict strong antibunching of counter-polarized light emission from the non-pumped auxiliary cavity. This scheme due to quantum interference is robust against surface scattering of pumping light, which can be suppressed both by spatial and polarization filters

Entangled-photon generation in nano-to-bulk crossover regime

We have theoretically investigated a generation of entangled photons from biexcitons in a semiconductor film with thickness in nano-to-bulk crossover regime. In contrast to the cases of quantum dots and bulk materials, we can highly control the generated state of entangled photons by the design of peculiar energy structure of exciton-photon coupled modes in the thickness range between nanometers and micrometers. Owing to the enhancement of radiative decay rate of excitons at this thickness range, the statistical accuracy of generated photon pairs can be increased beyond the trade-off problem with the signal intensity. Implementing an optical cavity structure, the generation efficiency can be enhanced with keeping the high statistical accuracy.Comment: 9 pages, 3 figure