High resolution up-conversion imaging in the 10 μm band under incoherent illumination (2505.24367v1)

Abstract: Long-wavelength infrared band exhibits significant utility in thermal signature acquisition and molecular spectral analysis, among other applications. The up-conversion detection technique enables effective signal transduction into the detection bandwidth of silicon-based photodetectors, thereby facilitating high-sensitivity photonic measurements. We realized high-resolution up-conversion imaging for incoherent thermal targets in the 10 {\mu}m spectral regime for the first time. Furthermore, this work presents the first derivation of analytical models characterizing depth of field and astigmatic aberration in up-conversion imaging systems, which show excellent agreement between theoretical and experimental results. The results demonstrate generalisability to various up-conversion imaging systems, thus providing critical insights for the design and optimisation of such systems.