High-efficiency plasmonic filter-based microlens array for multispectral infrared sensor

Multispectral infrared sensor is a novel technology for detecting infrared, providing simultaneous spectral and spatial information of the target object. However, conventional multispectral infrared sensors face limitations in quantum efficiency due to a low pixel filling ratio. The integration of bandpass filters and sensors poses challenges, including processing difficulty, filter layer thickness, and material constraints. In this work, we present a highly efficient, miniaturized optical filter with a plasmonic filter-based microlens array for a high-efficiency multispectral infrared sensor. Microlens arrays enhance light-gathering efficiency in infrared elements, resulting in high quantum efficiency, while the plasmonic filter, utilizing a 3D post array nanostructure, offers wavelength selectivity. This approach streamlines the integration of micro/nanostructures into infrared imaging sensors, significantly enhancing sensing performance beyond existing methods.