Spatial Differential Metasurface With Wavelength-Multiplexing

The development of artificial intelligence and big data has put forward higher requirements for computing devices, and metasurface-based optical devices have attracted attention due to their optical advantages.With the increase in data capacity and the trend of high integration, optical devices are beginning to develop towards multi-dimensional devices, among which wavelength-multiplexing is a method. Here, we propose a spatial differential metasurface with a honeycomb photonic structure as the basic unit to deal with wavelength-multiplexed optical fields, where differential operation is simultaneously performed on two-dimensional (2D) spatial optical fields with incident wavelengths of 1344nm and 1508nm. To verify the effectiveness of the wavelength-multiplexed spatial differentiator, the optical transfer function of the metasurface in one-dimensional (1D) space and 2D space at different wavelengths are numerically simulated and applied to the 1D Gaussian function and 2D image, respectively. The proposed metasurface holds important reference value for the implementation of wavelength-multiplexed differential operators, which provides new opportunities for multi-dimensional optical computing.