Space Application Requirement Breakdown and Sensor Concept Implementation for MCT-Based LWIR and VLWIR 2D High-Performance Focal Plane Detector Arrays at AIM

Abstract

Future demanding scientific space and earth observation missions such as for exoplanet atmospheric spectral analysis or earth climate monitoring will define new benchmarks in technological feasibility and come along with increasingly stringent requirements on instrument subsystems. The requirements imposed on infrared detectors are dependent on the type of optical instrument, the chosen observation approach and the spectral range to be covered. With advanced detector architectures on hand and suitable␣technology approaches in mind, various electrical and electro-optical quantities have to be traded off against each other and possibly be prioritized, reflecting the specific instruments’ needs. From such considerations, implications on the detector material, design and processing arise. In this methodological paper, we will illustrate specific trade-off considerations for focal plane detector arrays (FPAs) based on mercury cadmium telluride (MCT) as detector material, e.g. with respect to modulation transfer function (MTF), detection efficiency (QE), noise level, defect density, etc. As an illustration, we will discuss simulation and implementation approaches and solutions found for a presently ongoing cornerstone pre-development activity in the long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR). In particular, we will consider the thermal infrared (TIR) channels of the European Space Agency (ESA) Land and Surface Temperature Monitoring Mission (LSTM) observation instrument, for which we will present a photodiode array design approach balanced for key electro-optical FPA performance parameters.