Abstract
We examine a contradirectional asymmetric nonlinear coupler composed of a linear waveguide and a nonlinear waveguide operating by second harmonic generation. For this we develop a new consistent approach to quantum contradirectional propagation. Using a short-length approximation or a strong stimulating field in the second harmonic mode, we can demonstrate an effective transfer of non-classical properties of light from nonlinear to linear waveguides analysing quadrature and integrated intensity fluctuations, photon number distribution, reduced factorial moments and uncertainty product. Effects of non-classical behaviour of incident beams and of external noise are involved.