Development of low SWaP and low noise InGaAs detectors

In recent years SCD has developed InGaAs/InP technology for Short-Wave Infrared (SWIR) imaging.  The first product, Cardinal 640, has a 640x512 (VGA) format at 15μm pitch, and more than two thousand units have already been delivered to customers. Recently we have also introduced Cardinal 1280 which is an SXGA array with 10μm pitch aimed for long-range high end platforms [1].
One of the big challenges facing the SWIR technology is its proliferation to widespread low cost and low SWaP applications, specifically Low Light Level (LLL) and Image Intensifier (II) replacements. In order to achieve this goal we have invested and combined efforts in several design and development directions:
1. Optimization of the InGaAs pixel array, reducing the dark current below 2fA at 2 C in order to save TEC cooling power under harsh light and environmental conditions.
2. Design of a new "Low Noise" ROIC targeting 15e noise floor and improved active imaging capabilities
3. Design of compact, low SWaP and low cost packages. In this context we have developed 2 types of packages: a non-hermetic package with thermo-electric cooler (TEC) and a hermetic TEC-Less ceramic package.
4. Development of efficient TEC-Less algorithms for optimal imaging at both day-light and low light level conditions.
The result of these combined efforts is a compact low SWaP detector that provides equivalent performance to Gen III image intensifier under starlight conditions. In this paper we will present results from lab and field experiments that will support this claim.

Keywords: Infrared Detector, Focal Plane Array, InGaAs, low SWaP, low light level

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