Narrowband Perfect Absorber for Infrared Sensing

SRICO proposes to combine metamaterial narrowband absorbers and SRICO-proprietary thin film pyroelectric thermal detectors to produce ultra low size, weight, power and cost (SWAP-C) room temperature stand-off chemical sensors. Metamaterial narrowband absorber elements are integrated into the thin film pyroelectric detector process to provide conversion of radiation to heat, which is then sensed by the pyroelectric detector. Radiation outside a narrow absorption band is reflected by the metamaterial element. In addition, the device is engineered to reflect radiation that falls outside a narrow field of view or acceptance cone angle to mitigate self-radiance effects. This spectrally and aperture selective absorption suppresses blackbody radiation and enables the room temperature pyroelectric sensor to emulate the intrinsic noise rejection of cooled semiconductor band-gap devices. An array of pyroelectric metamaterial absorber elements tuned to different wavelengths can be formed on a silicon CMOS circuit to produce a highly compact and high speed long wave infrared (LWIR) spectrometer for mobile passive stand-off chemical sensing. In Phase I, SRICO proved the concept of the proposed technology fabricating and testing single element narrowband MMPA pyroelectric elements. In Phase II, SRICO will optimize the MMPA sensor element design and demonstrate multi-element prototypes in the chemical sensing application. Compact, low cost and spectrally resolved stand-off chemical sensors that operate at room temperature will have broad applicability to a large number of important defense, industrial, medical, and environmental applications.