Wavelength division multiplexing large-aperture multi-order differential metasurface calculator

Optical differentiation is crucial for high-speed image processing, but most optical analog spatial differentiators based on metasurfaces are currently limited to a single type of low-order differentiation operation. We present a dielectric metasurface composed of silicon hollow cylinders that leverages electric quadrupole (EQD) and magnetic dipole (MD) resonances to achieve wavelength-tunable two-dimensional (2D) multi-order differentiation. Specifically, at 1340 nm (MD-dominant), 1140 nm (hybrid EQD–MD), and 1010 nm (EQD-dominant), the metasurface performs second-, fourth-, and sixth-order differentiations, respectively. The device features a 430-nm bandwidth, a maximum numerical aperture of 0.71, and a maximum transmittance of 96%, enabling high-quality edge extraction for complex images. We believe this to be the first integration of wavelength-division multiplexing and multi-order differentiation in a single-layer metasurface, advancing compact and multifunctional optical computing for applications such as autonomous driving and medical imaging.