BAE Systems' SMART (Stacked Modular Architecture High-Resolution Thermal) Chip Camera provides very compact long-wave infrared (LWIR) solutions by combining a 12 μm wafer-level packaged focal plane array (FPA) with multichip-stack, application-specific integrated circuit (ASIC) and wafer-level optics. The key innovations that enabled this include a single-layer 12 μm pixel bolometer design and robust fabrication process, as well as wafer-level lid packaging. We used advanced packaging techniques to achieve an extremely small-form-factor camera, with a complete volume of 2.9 cm<sup>3</sup> and a thermal core weight of 5.1g. The SMART Chip Camera supports up to 60 Hz frame rates, and requires less than 500 mW of power. This work has been supported by the Defense Advanced Research Projects Agency’s (DARPA) Low Cost Thermal Imager − Manufacturing (LCTI-M) program, and BAE Systems’ internal research and development investment.
Seventeen (17) µm pixel Long Wave Infrared (LWIR) Sensors based on vanadium oxide (VO<sub>x</sub>) micro-bolometers have been in full rate production at BAE Systems’ Night Vision Sensors facility in Lexington, MA for the past five years. We introduce here a commercial camera core product, the Airia-M<sup>TM</sup> imaging module, in a VGA format that reads out in 30 and 60Hz progressive modes. The camera core is architected to conserve power with all digital interfaces from the readout integrated circuit through video output. The architecture enables a variety of input/output interfaces including Camera Link, USB 2.0, micro-display drivers and optional RS-170 analog output supporting legacy systems. The modular board architecture of the electronics facilitates hardware upgrades allow us to capitalize on the latest high performance low power electronics developed for the mobile phones. Software and firmware is field upgradeable through a USB 2.0 port. The USB port also gives users access to up to 100 digitally stored (lossless) images.
BAE Systems continues to make dramatic progress in uncooled microbolometer sensors and applications. This paper
will review the latest advancements in microbolometer technology at BAE Systems, including the development status of
17 micrometer pixel pitch detectors and imaging modules which are entering production and will be finding their way
into BAE Systems products and applications. Benefits include increased die per wafer and potential benefits to SWAP
for many applications. Applications include thermal weapons sights, thermal imaging modules for remote weapon
stations, vehicle situational awareness sensors and mast/pole mounted sensors.
Proc. SPIE. 7298, Infrared Technology and Applications XXXV
KEYWORDS: Staring arrays, Bolometers, Microbolometers, Long wavelength infrared, Visual process modeling, Fluctuations and noise, Data modeling, Infrared radiation, Systems modeling, Standards development
BAE Systems has continued to advance its 17 μm pitch LWIR 640 x 480 microbolometer technology with
improvements in pixel performance and initial production for several emerging products. In addition, we have
developed short time constant variants of our standard pixel design to support applications requiring short thermal time
constants. The technology is expanding to include a 1024x768 format megapixel FPA to support higher resolution
BAE Systems has advanced its 17 μm pitch LWIR 640 x 480 microbolometer
technology with improvements in pixel performance and introduction of a new 17 μm
pitch ROIC. We have fabricated, characterized, and demonstrated high-yielding 17 μm
pitch FPAs using our new ROIC, and have successfully demonstrated them at the system
level. This new technology builds on our 28 μm FPA production experience and
implements our high-performance single-level microbolometer process at 17 μm pitch.
We present initial results and imagery. These 17 μm FPAs have exceptional
performance and provide the path to next generation microbolometer applications.
BAE Systems has developed an advanced 640 x 480 focal plane array (FPA) with a 17 &mgr;m pixel pitch. Sensitivity of ≤ 50 mK was demonstrated and the FPAs were used in imaging demonstrations. Successful scaling of BAE Systems' patented single contact per pixel, single-level microbolometer process to 17 &mgr;m pitch provides a path toward next generation microbolometer imaging systems.
BAE Systems has made dramatic progress in uncooled microbolometer sensors and applications in the last year. The topics covered in this paper are: results and video from our latest 640x480 FPAs with sensitivities of better than 50 mK (f/1) and overviews of systems for military and commercial applications.
BAE SYSTEMS has made tremendous progress in uncooled technology and systems in the last year. In this paper we present performance results and imagery from our latest 640x480 and 320x240 small pixel focal plane arrays. Both were produced using submicron lithography and have achieved our lowest NETDs to date. Testing of the 320x240 devices has shown TNETDs of 30mK at F/1. Video imagery from our 640 x 480 uncooled camera installed in a POINTER Unattended Aerial Vehicle is also shown. In addition, we introduce our newest commercial imaging camera core, the SCC500 and show its vastly improved characteristics. Lastly, plans for future advancements are outlined.
320×240 and 640×480 small pixel uncooled microbolometer focal plane arrays have been developed that reduce overall sensor size, weight, power consumption, and cost. At the same time, these sensors still provide the high quality image resolution needed for target recognition and identification. These newly developed small uncooled thermal imaging sensors are being demonstrated in several attended and unattended sensor applications that include Unattended Ground Sensors, Micro Air Vehicles, and Infrared Helmet Sights. This paper describes recent developments at BAE SYSTEMS in uncooled microbolometer sensor technology for unattended sensor applications and presents the latest performance and image data for our 2nd generation systems.
Uncooled microbolometer thermal imaging sensor technology has begun to successfully address military, government and commercial applications in the real world. BAE SYSTEMS, located in Lexington MA, has been involved in the design and development of uncooled IR technology since the early 1980s. Our current MicroIR<SUP>TM</SUP> products are based on vanadium oxide (VO<SUB>x</SUB>) microbolometers. Thousands of uncooled microbolometer thermal imaging sensors are now being produced and sold annually. A the same time, applied research and development on the technology continues to improve the basic products and make them suitable for new applications. In this paper we report on the status and improvements achieved in the MicroIR<SUP>TM</SUP> product line, based on 320 X 240 element and 160 X 120 element FPA's with 46 μm pixel pitch. Other near term MicroIR<SUP>TM</SUP> products include 320 X 240 and 640 X 480 FPA's with 28 micrometers pixel pitch and measured sensitivities below 50 mK. In the systems area we discuss development and testing of a Light Thermal Weapon Sight (LTWS) for the U.S. Army, being developed by BAE SYSTEMS in partnership with Thales, based upon our uncooled MicroIR<SUP>TM</SUP> focal plane arrays (FPA) and systems. The LTWS prototypes were based upon our Standard Imaging Module SIM200, which employs our LAM2C, 320 X 240 element, microbolometer FPA. Finally we discuss the 480 X 640 element FPA and its application to the Heavy Thermal Weapon Sight application.
Sanders IR Imaging Systems (IRIS), a Lockheed Martin Company, has made recent improvements in high performance uncooled IR focal plane arrays and systems. This paper provides performance results for three of these new FPAs and systems. First we discuss a new 320 X 240, 46 micrometer pitch FPA, which when put into a system with a transmission of 74%, will provide a system NETD of < 26 mK (F/0.8, 60 Hz). This FPA has a power of < 250 mW (which includes on-chip 14 bit analog to digital conversion), and virtually no crosstalk from saturation. Second, we discuss the first ever 640 X 480 element uncooled IR camera. This camera, which is based on a 28 micrometer pitch microbolometer staring FPA, produces a system sensitivity of < 150 mK, (F/1, 30 Hz) and has a Minimum Resolvable Temperature Difference of < 0.4 degrees Celsius at the Nyquist frequency. Finally, we have developed a new lightweight thermal weapons sight (TWS). Our TWS, which weighs < 3 lbs. (with battery) and operates over the -37 degrees Celsius to +49 degrees Celsius temperature range, has demonstrated a boresight retention of < 0.2 mrad after 1000's of rounds were fired.
Lockheed Martin is developing the first ever 640 X 480 uncooled microbolometer camera. This camera, designated the LTC650, has a new 28 micrometers pitch 640 X 480 microbolometer focal plane array and electronics which operate at a 30 Hz frame rate. The electronics are based on previous successful 320 X 240 camera electronics which use low power, high performance DSP and FPGA technology. A DSP based software solution provides flexibility to answer the challenge of change and varied customer needs while meeting the low cost, low power, and low real estate requirements of portable, hand held applications. Test data for the first camera are presented.
Loral Infrared & Imaging Systems is developing low cost, high performance, uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding excellent infrared imaging performance. Here, we report on the development of an uncooled sensor, the LTC500, which incorporates an all digital focal plane array and has a measured NETD of less than 70 mK. The focal plane array and the electronics within the LTC500 have been designed as an integrated unit to meet a broad range of end user applications by providing features such as nonuniformity correction, autogain and level, NTSC video, and digital outputs. The 327 X 245 element focal plane array has a 46.25 micrometers pixel pitch and an on focal plane array 14 bit to analog to digital converter (ADC). The ADC has a measured instantaneous dynamic range of more than 76 dB at a 6.1 MHz output data rate and 60 Hz frame rate. The focal plane array consumes less than 500 mW of power, of which less than 250 mW is used in the ADC. An additional 36 dB of digital coarse offset correction in front of the ADC on the focal plane array results in a total electronic dynamic range of 112 dB. The MRT of the LTC500 camera has been measured at less 0.2 C at f<SUB>o</SUB>.
Loral Infrared & Imaging Systems is developing low cost, high performance uncooled infrared imaging products for both military and commercial applications. These products are based on the microbolometer technology, a silicon micromachined sensor which combines the wafer level silicon processing with a device structure capable of yielding NETD performance of better than 40 mK. To achieve a low cost sensor, Loral is proceeding with an integrated approach to the design and manufacturing processes associated with each major element of the uncooled sensor: focal plane array, electronics, optics and housings. Loral's 327 by 245 focal plane array has a 46.25 micrometer pixel pitch and incorporates a CMOS readout integrated circuit (ROIC). The ROIC has been designed to greatly simplify the external electronics, and features a single output which can operate at both 60 Hz (NTSC) and 50 Hz (PAL) video rates. The sensor electronics have been designed to meet a broad range of end user applications by providing both analog video and digital outputs with a large selection of user definable options and operating modes. To achieve low manufacturing costs across multiple end user applications, common optical interfaces, structural components, and manufacturing processes are being utilized. Sensor NETD is projected to be 40 mK normalized to f/1 and a 30 Hz frame rate. MRT is projected to be better than 0.1 degree Celsius at f<SUB>0</SUB>.
We have utilized a semiconductor optical amplifier (SOA) as an optical gain/absorption switch and have demonstrated an array of such switches in the form of a monolithic 4 X 4 optical crossbar switch. This device is completely nonblocking and can be operated in either a point-to-point or broadcast mode, simultaneously linking any combination of four input/output ports on one side with any combination of ports on the other. It is housed in a standard hybrid flatpack, with external control leads and eight connectorized optical fibers. The device consists of ridge waveguides, etched-facet turning mirrors, and etched T-branches laid out into an all- optical-path network. It is fabricated from a single GaAs quantum well/AlGaAs GRINSCH epitaxial structure on an N+ GaAs substrate. Because the paths are optical, they transmit signals in either direction -- i.e., the device can operate in a duplex (bidirectional) mode. We have demonstrated switching functionality, simultaneous routing of two digital FM video signals, and routing of pseudo-random NRZ data.
1.1 W cw has been achieved from a 10-amplifier coherent array with an electrical to optical conversion efficiency of 28%. The amplifiers were injected with 20 mW from a master oscillator via a single-mode polarization-preserving optical fiber. Approximately 90% of the output power from the amplifier array was locked to the master oscillator's frequency.