Fig. 1: Integrated metasurface system for spatial pattern classification.
From: Integrated photonic metasystem for image classifications at telecommunication wavelength
a Schematics of the system architecture. As an example, a pattern ‘Y’ with less than 90 femtosecond pulse duration is coupled to the integrated metasystem through the input grating coupler array (green gratings). Through the diffractions through the metasystem, the light is converged onto the position on the output plan where the correspondent waveguide channel locates. b Subwavelength structure manifested diffraction between metasurface layers. The numerically simulated light intensity is superimposed onto the optical microscope image of a fabricated metasystem. c Amplitude and phase of the complex transmission coefficient versus the slot length L (indicated in the inset of d) with the fixed slot width of 100 nm. d Amplitude and phase of the complex transmission coefficient versus the incident angle (θ indicated in b) with the slot width of 100 nm and L of 2.5 \({{{{{\rm{\mu }}}}}}{{{{{\rm{m}}}}}}\). Inset: Scanning electron microscope (SEM) image for the zoom-in view of the metasurface cell in b.
