Narrowband Perfect Absorber for Infrared Sensing

SRICO proposes to combine metamaterial narrowband absorbers and SRICO-proprietary thin film lithium tantalate (TFLT) pyroelectric thermal detectors to produce ultra low cost, size, weight and power (SWaP) room temperature stand-off chemical sensors. Metamaterial narrowband absorber elements will be integrated into the TFLT 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 metamaterial device can be 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 sensor to achieve shot limited performance. An array of TFLT metamaterial absorber elements tuned to different wavelengths can be formed on a silicon CMOS circuit to produce a highly compact and high speed room temperature long wave infrared (LWIR) spectrometer for stand-off chemical sensing. 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.