|Acquisition Program: ||PEO Intelligence, Electronic Warfare and Sensors|| Objective: ||To develop and demonstrate a solid state photodetector technology that exhibits passive low light level performance equal to or exceeding that of current Gen III image intensifiers. The goal is to develop a low cost, small in size and weight, low power, man-portable, solid state imager as a video based sensor technology alternative to the current image intensifier tube based imagers. The imager is to operate at 30Hz frame rate minimum (60Hz frame rate desired), with no or minimum cooling required and demonstrates low light level (overcast starlight) performance.
|| Description: ||Current image intensifier (I2) goggle technology for man-portable applications is bulky in size and weight and does not lend itself to be fused with other solid state sensors such as shortwave infrared (SWIR), midwave infrared (MWIR) and/or longwave infrared (LWIR). Conventional silicon Charge Coupled Devices (CCDs) and Complementary Metal Oxide Semiconductor (CMOS) imagers are incapable of passive low light level performance due to high dark current and high readout noise limitations. For passive low light level imaging, the signal must be maximized and noise minimized. CCDs for astronomy applications have been shown to have low light level performance capability by cooling to reduce dark current and by operating at a much slower frame rate which effectively maximize the integration time and reduce the readout noise. Recent impact ionization CCD developments potentially could provide low light level performance at normal video frame rates however it is unclear if this technology is suitable for man-portable applications due to the cooling requirement to reduce dark current and sustain sufficient gain. This topic seeks to develop a low cost, low power, uncooled or minimally cooled , man-portable solid state sensor operating at normal video rates to replace the current I2 goggle technology. To achieve performance comparable to Gen III I2 goggle technology, the solid state technology must exhibit high gain with low excess noise, high quantum efficiency and low dark current at ambient temperature. The technology must show a clear path to a compact, low power, small pixel pitch, high resolution imager. The target imaging sensor should be of 1280 x 1024 SVGA format (minimum) or HDTV 1920 x 1080 (desired), 12 um pitch or less, 30 Hz ( minimum) or 60Hz (desired) operation, with 40 degree field of view optics.
|| ||PHASE I: Demonstrate the technical feasibility of the proposed approaches through design and analysis. The proposed design shall be optimized for low dark current, low read noise, large dynamic range and linearity, low power, and high sensitivity. Test circuits or small format arrays to demonstrate the design concepts are highly desirable in the Phase I effort.
|| ||PHASE II: Using the results of Phase I effort, build, demonstrate and deliver a man-portable solid state imager/camera system with passive low light level performance that is comparable or exceeds the current Gen III I2 goggle technology. Demonstrate a clear path to low cost production.
|| ||PHASE III: The commercialization of this technology is expected to provide low cost, high performance low light level imagers for potential uses in a variety of commercial applications including transportation, security/law enforcement, medical imaging, border patrol, homeland security as well as military applications such as night vision devices.
|| References: ||
1. P. Jerram, P. J. Pool, R. Bell, D. J. Burt, S. Bowring, S. Spencer, M. Hazelwood, I. Moody, N. Catlett, and P. S. Heyes, “The LLCCD: low-light imaging without the need for an intensifier”, in Proc. SPIE, 4306, pp. 178-186, May 2001.
2. D.Rathman, K. Pedrotti, S. Gaalema, et. al., “Hybrid Low-Light–Level CMOS Sensor Development”, in Proc. SPIE, 1998.|
|Keywords: ||low light level, near infrared, NIR, shortwave infrared, SWIR, night vision|