Double-Band Metasurface Infrared Optics for Integrated Multichannel Spectral Sensors

Simultaneously identifying the composition of mixtures and determining their concentration levels has aroused much attention in recent years to meet large demands compact low-cost infrared spectral sensors replace conventional bulky counterparts with costly separated components. In this work, we propose a design method for multichannel metasurface array optics covering two bands middle-wave (MWIR) long-wave (LWIR) construction integrated gas sensors. The use microstructures same height realizes effective filtering focusing electromagnetic waves at multiple wavelengths both bands, which is beneficial decrease manufacturing costs. Four-channel lens arrays filter operating 3.5, 9.7, 10.6, $3.9 \mu \text{m}$ corresponding absorption peaks three gases ethanol, ammonia, ethylene, one reference wavelength, respectively, were designed produced by photolithographic patterning dry etching processes on silicon substrates. have advantages easy fabrication integration wideband detector form detector, meets requirements small volume low cost advanced applications portable smart sensing systems Internet Things.