Night Vision Imaging in the Short-Wave Infra-Red (SWIR) has some unique advantages over Visible, Near Infra-Red (NIR) or thermal imaging. It benefits from relatively high irradiance levels and intuitive reflective imaging. InGaAs/InP is the leading technology for two-dimensional (2D) SWIR detector arrays, utilizing low dark current, high efficiency and excellent uniformity. SCD's SWIR Imager is a low Size, Weight and Power (SWaP) video engine based on a low noise 640x512/15μm InGaAs Focal Plane Array (FPA) embedded in a low cost plastic package which includes a Thermo-Electric Cooler (TEC). The SWIR Imager dimensions are 31x31x32 mm<sup>3</sup>, it weighs 50 gram and has less than 1.4W Power consumption (excluding TEC). It supports conventional video formats, such as Camera Link and BT.656. The video engine image processing algorithms include Non-Uniformity Correction (NUC), Auto Exposure Control (AEC), Auto Gain Control (AGC), Dynamic Range Compression (DRC) and de-noising algorithms. The algorithms are specifically optimized for Low Light Level (LLL) conditions enabling imaging from sub mlux to 100 Klux light levels. In this work we will review the optimized video engine LLL architecture, electro-optical performance and the applicability to night vision systems.
In recent years SCD has developed InGaAs/InP technology for Short-Wave Infrared (SWIR) imaging. The first product, Cardinal 640, has a 640×512 (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 . 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 20° 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.
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 a thousand units have already
We now present Cardinal 1280, having the smallest pitch available today (10μm), with a 1280x1024 (SXGA)
format. Cardinal 1280 addresses both long-range daylight imaging, and passive or active imaging in Low Light
Level (LLL) conditions.
The Readout Integrated Circuit supports snapshot imaging at 13 bit resolution with a frame rate of 160Hz at full
format, or a frame rate of 640Hz with 2x2 binning. It also has a Low Noise Imaging (LNIM) mode with 35ereadout
noise with internal Correlated Double Sampling (CDS). An asynchronous Laser Pulse Detection (ALPD)
mode is implemented with 2x2 binning in parallel to SWIR imaging (with 10 μm resolution). The new 10 μm
pixel is sensitive down to the visible (VIS) spectrum, with a typical dark current of ~ 0.5fA at 280K, and a
quantum efficiency >80% at 1550nm.
The Focal Plane Array is integrated into a ruggedized, high vacuum integrity, metallic package, with a Thermo-
Electric Cooler (TEC) for optimized performance, and a high grade Sapphire window. In this paper we will
present the architecture and preliminary measurement results.