Mid-Infrared on-Chip Computational Spectrometer Based on Plasmonic Metasurfaces

An on-chip computational spectrometer consisting of a planar array of broadband optical filters is proposed, which are formed by plasmonic metasurfaces. By adjusting the structural parameters of plasmonic metasurface, the optical characteristics of a stop-band filter in the mid-infrared band are realized. By applying compressive sensing (CS) and genetic algorithm (GA), the incident spectrum can be reconstructed. Simulation results show the proposed design can successfully reconstruct the spectra over the 1.5 to 4 μm spectral range with a full width at half maximum (FWHM) resolution of 30 nm and the bandwidth-resolution ratio (BRR) of 83.33. These results support future applications in mid-infrared on-chip spectrometers.