Study of new types of detectors in the SWIR: extension of the operating band beyond 1.7 μm

Abstract

In recent years, an interest in the detection of the Short Wave Infra-Red (SWIR) band has grown. In these wavelengths, we benefit both from the properties of the visible and thermal infrared, offering new information and a different contrast to the image. In the defense field, this band offers the possibility of passive and active imaging, as well as the detection of laser or thermal radiation from bodies above ambient temperature. The state-of-the-art III-V detectors in the SWIR are InGaAs photodiodes on InP substrate that are limited by a 1.7 µm cut-off wavelength. Super-lattice (SL) based detectors, that have been increasingly studied in recent years, make it possible to reach new cut-off wavelengths. Starting from the InGaAs on InP detector technology that has been mastered for more than ten years by THALES, the III-V Lab we propose to extend the detection range beyond 1.7 µm by introducing a SL in the active region of an InGaAs photodiode. We will present the results obtained up to 2.5 µm, as well as the solutions implemented to limit the carrier localization in the super-lattice and the associated QE degradation.