Photonic coupling between quadrature states of light in a homogeneous and optically linear dielectric medium

Two optical beams of the same frequency but different wave vectors propagating through a homogeneous dielectric medium can exchange photons with each other and/or undergo mutually induced phase shifts as a result of a stimulated Rayleigh emission underpinning the coupling term of the Poynting theorem. Quadrature states of the same optical wave exchange power as they propagate through a homogeneous and linear dielectric medium. Consequently, coupling of photons between two optical waveguides takes place in the shared cladding region.