Aspects of the present disclosure are directed to a photorefractive layer stack. A plurality of layers are stacked along in a stacking direction and designed so as to enable a photorefractive response. That is, a refractive index of the plurality of layers modulates in response to illuminating the plurality of layers with an optical pattern of modulated intensity. A plurality of electrically insulated areas are arranged in a plane perpendicular to the stacking direction. The plurality of electrically insulated areas are optically homogenous and prevent lateral diffusion between any two electrically insulated areas of the plurality of electrically insulated areas.