In this paper, we review selected imaging and related technology development programs in the Defense Advanced Research Projects Agency (DARPA) Microsystems Technologies Office (MTO). An overview is presented for the evolution of Joule-Thomson (J-T) micro-cryogenic cooler (MCC) technology. The initial design of a system on a chip method is shown for these micro-coolers to be used in conjunction with high operating temperature mid-wave infrared (MWIR) and long-wave infrared (LWIR) focal plane arrays. For the reflective visible band, results are shown for a gigapixel monocentric multi-scale camera design to solve the scaling issues for high pixel count and wide field of view. Lastly, we discuss two different approaches to multiband imaging and the potential advantages of this technology for the enhanced detection, recognition, and identification of targets.
In this paper, we review a few selected imaging technology development programs at the Defense Advanced Research Projects Agency (DARPA) in the reflective visible to the emissive/thermal long wave infrared (LWIR) spectral bands. For the reflective visible band, results are shown for two different imagers: a gigapixel monocentric multi-scale camera design that solves the scaling issues for a high pixel count, and a wide field of view and a single photon detection camera with a large dynamic range. Also, a camera with broadband capability covering both reflective and thermal bands (0.5 μm to 5.0 μm) with >80% quantum efficiency is discussed. In the emissive/thermal band, data is presented for both uncooled and cryogenically cooled LWIR detectors with pixel pitches approaching the fundamental detection limits. By developing wafer scale manufacturing processes and reducing the pixel size of uncooled thermal imagers, it is shown that an affordable camera on a chip, capable of seeing through obscurants in day or night, is feasible. Also, the fabrication and initial performance of the world’s first 5 μm pixel pitch LWIR camera is discussed. Lastly, we use an initial model to evaluate the signal to noise ratio and noise equivalent differential temperature as a function of well capacity to predict the performance for this thermal imager.
Advances in imaging technology have huge impact on our daily lives. Innovations in optics, focal plane arrays (FPA),
microelectronics and computation have revolutionized camera design. As a result, new approaches to camera design and
low cost manufacturing is now possible. These advances are clearly evident in visible wavelength band due to pixel scaling,
improvements in silicon material and CMOS technology. CMOS cameras are available in cell phones and many other
consumer products. Advances in infrared imaging technology have been slow due to market volume and many
technological barriers in detector materials, optics and fundamental limits imposed by the scaling laws of optics. There is of
course much room for improvements in both, visible and infrared imaging technology. This paper highlights various
technology development projects at DARPA to advance the imaging technology for both, visible and infrared. Challenges
and potentials solutions are highlighted in areas related to wide field-of-view camera design, small pitch pixel, broadband
and multiband detectors and focal plane arrays.