  Wavevector quasi-phase matching was devised in the 1960s as a way to boost
nonlinear interactions with efficient quantum noise squeezing as one
outstanding outcome. In the era of quantum technologies, we propose a new
coupling quasi-phase matching for efficient generation of multimode
downconverted quantum light in nonlinear waveguide arrays. We highlight this
technique achieving multimode quantum entanglement and Einstein-Podolsky-Rosen
steering buildup. We discuss the feasibility of this method with current
technology and demonstrate its competitiveness as a resource for continuous
variables quantum information.
