Enhanced Sensitivity to Blackbody Radiation in Spintronic Poisson Bolometers

Abstract

High-sensitivity long-wave infrared (LWIR) detection is crucial for observing weak thermal radiation. Recently, the Poisson bolometer has been proposed as a fundamentally new platform for uncooled infrared detection. In contrast to traditional analog detectors, where signal and noise are determined by continuous currents or voltages, the Poisson bolometer's signal and noise are governed by Poissonian counting statistics regardless of the light source. In this work, we demonstrate advancements in uncooled infrared detection towards cryogenic-level sensitivity through the integration of spintronic and plasmonic materials. Specifically, a spintronic Poisson bolometer is experimentally integrated with a plasmonic nanoantenna array optimized for broadband LWIR absorption to enhance the temperature increase of the sensing layer. The plasmonic absorber exhibits an absorptance exceeding 60\% across the LWIR spectrum, matching the peak of room-temperature blackbody radiation. We demonstrate that these devices are capable of achieving a noise equivalent differential temperature (NEDT) of 35 mK at a 50 Hz frame rate, demonstrating room-temperature performance comparable to the most sensitive uncooled LWIR detectors reported to date. This work opens up a pathway to removing bulky and expensive cooling requirements from high-sensitivity LWIR detection and imaging applications, such as remote sensing, high-speed imaging, and industrial monitoring.