Mid-infrared single-pixel imaging with a large-area GaAs sensor
Phys. Rev. Applied 26, 044009 – Published 2 October, 2026
DOI: https://doi.org/10.1103/6slr-r94y
Abstract
Nondegenerate two-photon absorption (ND-TPA) detection has emerged as a highly promising approach for room-temperature mid-infrared (MIR) imaging by exploiting the nonlinear interaction between infrared photons and pump radiation in wideband gap semiconductors. However, scaling ND-TPA imagers toward wide-field operation remains challenging because the nonlinear interaction strength rapidly decreases with enlarged sensing area, thereby degrading detection sensitivity. Here, we demonstrate a wide-field MIR single-pixel ND-TPA imaging system, in which two-photon optical encoding is implemented in a direct-band gap GaAs photomultiplier tube with large photosensitive area and high internal gain. By combining spatial multiplexing with single-element integrated detection, the proposed scheme effectively enhances the collection and accumulation of weak nonlinear signals under a pump irradiance significantly lower than previous requirements. Moreover, the system achieves a spatial resolution of over a 4-mm field of view, corresponding to a record-high space-bandwidth product of among existing TPA-based MIR imagers. This work establishes a scalable pathway toward wide-field and high-sensitivity MIR computational imaging, with promising applications in industrial inspection, remote sensing, and weak-target detection.
