Demonstration of a 5.5  <i>μ</i> m cutoff event-based sensor pixel and evaluation of sensitivity in the event-based and framing paradigms

Event-based sensors (EBSs) offer a promising alternative to traditional frame-based sensors for tracking and other applications, addressing limitations in dynamic range, power consumption, temporal resolution, and data volume. This is enabled by the self-resetting, asynchronous change-detection pixel design of EBSs. However, commercial-off-the-shelf event-based sensors lack the coverage of the mid-wave infrared (MWIR) wavelength range, a critical gap for many thermal sensing applications. This work presents a prototype MWIR EBS, an EBS pixel unit cell implemented on a printed circuit board and interfaced with a 5.5 μm cutoff nBn photodetector variable-area detector array held at 130 K. This configuration allows for measurements of the MWIR EBS pixel's S-curves across varying pixel sizes, providing insights into the detector's sensitivity and noise contribution to the user-defined contrast threshold and revealing potential limitations of interfacing III–V MWIR photodetectors. The source of the limitations observed in this work remains unknown; the theoretical analysis indicates that they are not likely the result of an injection efficiency issue. Finally, the impact of proton irradiation induced displacement damage in the photodetector on the photoreceptor output voltage is discussed.