Analysis of absorber based imaging systems with distributed incoherent sources

Abstract

Abstract-Passive imaging cameras at sub-millimeter wavelengths are currently entering a new era with the development of large format arrays of direct detectors. Several of these arrays are being developed with bare absorbing meshes without any antenna coupling (lens or horn) structures. This paper uses a spectral electromagnetic model to analyze the performance of absorber based focal plane arrays in comparison to antenna based systems. The methodology is particularly suited to derive guidelines for optimizing the resolution and the sensitivity of thermal imaging cameras at sub-mm wavelengths. The proposed method is validated with full-wave simulations.