Parallel multiplexing optical spatial differentiation based on a superposed complex amplitude filter

Optical differentiation has the advantages of ultrahigh speed and low power consumption over digital electronic computing. Various methods for single and switchable-order differential operations have been extensively studied and applied in fields such as image processing and optical analog computing. Here, we report a parallel multiplexing scheme of optical spatial differentiations via a superposition of multiple complex amplitude filters. The isotropic and anisotropic first- to fourth-order differentiation multiplexing, as well as various types of differentiation multiplexing are demonstrated both theoretically and experimentally. Multifunctional differential operations can be generated simultaneously, realizing the extraction of multiple feature information about amplitude and phase objects. This proof-of-principle work provides an approach for multiplexing optical spatial differentiation and a promising possibility for efficient information processing.