Over the past few years, a new type of High Operating Temperature (HOT) photon detector has been developed at SCD,
which operates in the blue part of the MWIR window of the atmosphere (3.4-4.2 μm). This window is generally more
transparent than the red part of the MWIR window (4.4-4.9 μm), especially for mid and long range applications. The
detector has an InAsSb active layer, and is based on the new "XBn" device concept. We have analyzed various electrooptical
systems at different atmospheric temperatures, based on XBn-InAsSb operating at 150K and epi-InSb at 95K,
respectively, and find that the typical recognition ranges of both detector technologies are similar. Therefore, for very
many applications there is no disadvantage to using XBn-InAsSb instead of InSb. On the other hand XBn technology
confers many advantages, particularly in low Size, Weight and Power (SWaP) and in the high reliability of the cooler
and Integrated Detector Cooler Assembly (IDCA). In this work we present a new IDCA, designed for 150K operation.
The 15 μm pitch 640×512 digital FPA is housed in a robust, light-weight, miniaturised Dewar, attached to Ricor's
K562S Stirling cycle cooler. The complete IDCA has a diameter of 28 mm, length of 80 mm and weight of < 300 gm.
The total IDCA power consumption is ~ 3W at a 60Hz frame rate, including an external miniature proximity card
attached to the outside of the Dewar. We describe some of the key performance parameters of the new detector,
including its NETD, RNU and operability, pixel cross-talk, and early stage yield results from our production line.
Since the late 1990s Semiconductor devices (SCDs) has developed and manufactured a variety of InSb two-dimensional (2D) focal plane arrays (FPAs) that were implemented in many infrared (IR) systems and applications. SCD routinely manufactures both analog and digital InSb FPAs with array formats of 320×256, 480×384, and 640×512 elements, and pitch size in the range 15 to 30 μm. These FPAs are available in many packaging configurations, including fully integrated detector-Dewarcooler-assembly, with either closed-cycle Stirling or open-loop Joule-Thomson coolers. In response to a need for very high resolution midwave IR (MWIR) detectors and systems, SCD has developed a large format 2D InSb detector with 1280×1024 elements and pixel size of 15 μm. The ROIC is fabricated in CMOS 0.18-μm technology, that enables the small pixel circuitry and relatively low power generation at the focal plane. The digital ROIC has an analog to digital (A/D) converter per-channel and allows for full frame readout at a rate of 100 Hz. Such on-chip A/D conversion eliminates the need for several A/D converters with fairly high power consumption at the system level. The digital readout, together with the InSb detector technology, lead to a wide linear dynamic range and low residual nonuniformity, which is stable over a long period of time following a nonuniformity correction procedure. A special Dewar was designed to withstand harsh environmental conditions while minimizing the contribution to the heat load of the detector. The Dewar together with the low power ROIC, enable a megapixel detector with overall low size, weight, and power with respect to comparable large format detectors. A variety of applications with this detector make use of different cold shields with different f-number and spectral filters. In this paper we present actual performance characteristics of the megapixel InSb detector and demonstrate its high manufacturability.
Pelican-D is a new digital 640x512 / 15μm InSb detector developed by SCD to serve a number of applications. The
Readout Integrated Circuit (ROIC) has a digital output which can be calibrated to a signal resolution in the 13-15 bit
range. Besides the digital output, the detector has some additional advantages over other MWIR detectors of the same
format. The high frequency of data output, which supports a full image frame rate of over 300Hz, is very useful in
systems that track fast evolving events such as Missile Warning Systems (MWS), Missile Seekers and some
Thermographic applications. Another important characteristic of the detector is related to an operation mode with
relatively low readout noise. This mode of operation is especially beneficial in applications where the background
radiation is low such as in long range surveillance systems. For imaging systems where very high sensitivity is required,
the ROIC can be coupled to an epi-InSb detector array and have a dark current at 77K that is lower by a factor of 15 with
respect to standard InSb. Alternatively, Pelican-D with epi-InSb can be operated at 95K with a standard dark current and
sensitivity. Such an elevated operating temperature enables the use of cryogenic coolers of relatively low size, weight
and power for applications such as Hand-held cameras, miniature gimbaled systems, and light UAVs. In this work we
present in detail the characteristic performance of the new detector and its applications.
Modern electro-optical systems contain several components such as thermal imager, laser designator, laser range finder,
etc. The demand for compact systems with low power consumption and low cost can be addressed by incorporating
some of the traditional system abilities into the IR detector. We present SNIR, a new type of detector, which consists of a
Read Out Integrated Circuit (ROIC) with advanced on-chip signal processing. The ROIC is flip chip-bonded to a
640x512 InSb detector array of 15μm pitch. SNIR digital ROIC can be operated in either one of the following four
different modes of operation. The first operation mode is standard thermal imaging, which has typical functionalities and
performance of MWIR detector. The second operation mode is a dual-function mode that includes both standard thermal
imaging and information on Asynchronous Laser Pulse Detection (ALPD) for each pixel. The detection probability of a
laser pulse is significantly increased by integrating a dedicated in-pixel circuit for identifying a fast signal temporal
profile. Since each pixel has internal processing to identify laser pulses, it is possible also to measure the elapsed time
between a trigger and the detection of a laser pulse. This yields a third mode of operation in which the detector is
synchronized to a laser and becomes a Two-dimensional Laser Range Finder (TLRF). The forth operation mode is
dedicated to Low Noise Imaging (LNIM) for the SWIR band, where the IR radiation signal is low. It can be used in both
passive or active imaging. We review some of the predicted and measured results for the different modes of operation,
both at the detector level and at the system level.
Over the last decade, SCD has developed and manufactured high quality InSb Focal Plane Arrays (FPAs), that are currently used in different applications worldwide. SCD's production line includes InSb FPAs with mid format (320x256 elements), and large format (640x512 elements), all available in various packaging configurations, including fully integrated Detector-Dewar-Cooler Assemblies (DDCA). Many of SCD's products are fully customized for customers' needs, and are optimized for each application with respect to the weight, power, size, and performance.
In 2006, SCD has added to its broad InSb product portfolio the new "Pelican" detector family. All Pelican detectors include a large format 640×512 InSb FPA with 15&mgr;m pitch, which is based on the FLIR/Indigo ISC0403 Readout Integrated Circuit (ROIC). Due to its small size, the Pelican FPA fits in any mid format Dewar, enabling upgrading of mid format systems with higher spatial resolution due to its good MTF.
This work presents the high performance of Pelican products. As achieved in all SCD's InSb DDC's, the Pelican detectors demonstrate high uniformity and correctability (residual non uniformity less than 0.05% std/DR) and remarkable operability (typically better than 99.9%). The Pelican FPA can be integrated in various DDCA configurations as per application needs, such as light weight, low power and compact form for hand held imagers, or a rigid configuration for environmentally demanding operating and storage conditions.
Over the past few years SCD has developed a new InAlSb diode technology based on Antimonide Based Compound Semiconductors (ABCS). In addition SCD has lead in the development of a new standard of silicon readout circuits based on digital processing. These are known as the "Sebastian" family of focal plane processors and are available in 384 × 480 and 512 × 640 formats. The combination of ABCS diode technology with digital readout capability highlights an important cornerstone of SCDs 3rd generation detector program. ABCS diode technology offers lower dark currents or higher operating temperatures in the 100K region while digital readouts provide very low noise and high immunity to external interference, combined with very high functionality. In this paper we present the current status of our ABCS-digital product development, in which the detectors are designed to provide improved performance characteristics for applications such as hand-held thermal imagers, missile seekers, airborne missile warning systems, long-range target identification and reconnaissance, etc. The most important Detector-Dewar-Cooler Assembly (DDCA) parameters are reviewed, according to each specific application. Benefits of these products include lower power consumption, lighter weight, higher signal-to-noise ratio, improved cooler reliability, faster mission readiness, longer mission times and more compact solutions for volume-critical applications. All these advantages are being offered without sacrificing the standard qualities of SCDs InSb Focal Plane Arrays (FPAs), such as excellent radiometric performance, image uniformity, high operability and soft-defect cosmetics.
For the past few years SCD has been developing a series of Infra Red (IR) detectors based on the well established technologies of InSb diodes and the most advanced analogue and digital signal processors. These detectors exhibit special modes of operation combined with a high level of performance, which enables the detectors to be optimized within a large variety of applications. Among these applications the most demanding are considered to be those related to Missile Warnings Systems (MWS) and firing identification. For these high-end applications, a combination of suitable operation modes and high performance is required, including: large dynamic range, high frame rate, high sensitivity at low signal and a smooth transition of operation mode from frame to frame. The first detector developed for MWS is the "Blue Fairy" detector which has 320x256 elements with a 30μm pitch. After the "Blue Fairy" a family of new generation digital detectors was developed, starting with "Sebastian". Sebastian is based on a novel digital Focal Plane Processor (FPP) with a 20μm pitch and a format of 640×512. Next, for the mid format, a digital detector with 480×384 elements was developed, based on the same concept as the large format Sebastian detector but with some additional functionality. In this paper the special features and performance of these detectors are presented showing their advantages for MWS applications.
SCD has developed a High Performance Detector Dewar Cooler (DDC) called “Piccolo” for IR detection in the MWIR, which has low power consumption, low weight and low cost. The DDC characteristics are optimized for handheld camera applications. The Piccolo DDC is based on the advanced “Blue Fairy” Focal Plane Processor (FPP) which is bonded to a 320x256 element InSb FPA. The Blue Fairy FPP is used in a special mode of operation for very low power consumption of less than 25mW. A special dewar has been developed for the Piccolo which has a low heat load of less than 140mW. A new cooler designed for low power consumption and low weight is integrated into the dewar. This results in a total power consumption for the DDC at an ambient temperature of 23°C of below 5W. The total weight of the whole DDC is less than 400gr. All the components of the Piccolo were designed for low cost production while keeping the high performance and reliability standards of all SCD detectors.
Proc. SPIE. 5406, Infrared Technology and Applications XXX
KEYWORDS: Target detection, Staring arrays, Digital signal processing, Sensors, Field programmable gate arrays, Detector development, Signal processing, Target recognition, Signal detection, Single crystal X-ray diffraction
After completing the development of a digital detector with a format of 640x512 elements ("Sebastian"), SCD is now developing a mid format digital detector with 480x384 elements. This detector is based on the same concept as Sebastian, which was introduced last year at the SPIE conference in Orlando. The 480x384 element detector has all the features and performance of Sebastian as then introduced, and in addition exhibits some additional functionality. The format of the 480x384 element detector was chosen in order to maintain the same active area as in a standard format 320x256 element detector of today. Thus with specific system optics, a higher resolution is achieved with our new detector. As a direct consequence, the detection range is increased by 22-35% depending on the target type, when using this detector instead of the conventional 320x256 element detector in a typical system. The 480x384 element detector is designed to be integrated both into imaging systems and into head seekers missile-applications. In this paper we present the concept and the basic structure of the detector, the special operation modes unique to the digital detector, and the results of detection range calculations.
Proc. SPIE. 5074, Infrared Technology and Applications XXIX
KEYWORDS: Staring arrays, Infrared sensors, Digital signal processing, Sensors, Interference (communication), Field programmable gate arrays, Signal processing, Analog electronics, Signal detection, Single crystal X-ray diffraction
A Focal Plane Array (FPA) with a digital output for cooled IR detectors has recently attracted a lot of attention due to its advantages over detectors with analog outputs. Of special importance is the potential to have a better long term stability of the Residual Non Uniformity (RNU). Last summer SCD introduced a new high performance digital signal processor for 640x512 InSb infrared detectors, which includes analog to digital conversion performed inside the signal processor itself (at the focal plane). This signal processor has been bonded to InSb detector arrays and tested both electrically and radiometrically within a dewar. Special proximity electronics was developed for the operation of the FPA, including a Field Programmable Gate Array (FPGA) device. The complete device functions as a multi-chip system, enabling high degree of flexibility and easy integration at the system level. The total power dissipation of the FPA is less than 100mW at a frame rate of 100Hz, which is even less than that obtained with comparable/conventional analog FPAs. The NETD of the detector is less than 10.5mK at 50% of the full range 13Me-. The RNU is less than 0.02%STD/DR from 2% up to 90% of the full range. It is important to note that in the case of a digital detector the readout noise the NETD and the RNU of the detector are the total system values. This stand alone Digital Detector Dewar Cooler (D3C) presents a new industrial standard for cooled IR detectors.
SCD Focal Plane Arrays (FPAs) are based on 320×256 InSb elements, or 640×512 InSb elements. In this paper we introduce the outstanding FPA based on the signal processor 'blue fairy' (BF) that has been designed at SCD, and is now in standard production for the 320×256 InSb FPAs. The BF Focal Plane Processor (FPP) enables integration capacity of more than 15Me- at Integrate While Read (IWR) mode, and more than 30 Me- at Integrate Than Read (ITR) mode. A combined mode for large dynamic range with high sensitivity is possible. An excellent linearity and residual non-uniformity is achieved, starting from extremely low electron capacity up to 13Me- at IWR mode and 24Me- at ITR mode. Many other modes can be selected via a communication channel such as: ITR/IWR, one of seven different gains, one of seven different biases for the detector, windows size and window location. A Correlated Double Sampling (CDS) between frames and rows can be used for low frequency noise reduction, and/or any external electronic gain and offset drift corrections. All these features enable the integration of the BF FPA in large variety application, with high performance at each application.