High-resolution passive video-rate imaging at 350 GHz

We are developing a 350 GHz cryogenic passive video imaging system for use in standoff security applications. This demonstration system uses 800 photon-noise-limited superconducting transition edge sensor bolometers, read out using a time-division multiplexed readout system. It will image a 1 m x 1 m field of view at a standoff distance of 16 m to a resolution of approximately 1 cm at video frame rates (20 frames per second). High spatial resolution is achieved by the use of an f/2.0 Cassegrain optical system with 1.3 m primary mirror. Preliminary dark and optical testing of prototype detectors indicates that we can achieve a noise equivalent temperature difference (NETD) below 100 mK for the fully sampled 1 m x 1 m image at 20 frames per second. We report on the current status of development of this system.

[1]  N. Llombart,et al.  Penetrating 3-D Imaging at 4- and 25-m Range Using a Submillimeter-Wave Radar , 2008, IEEE Transactions on Microwave Theory and Techniques.

[2]  Peter A. R. Ade,et al.  The South Pole Telescope , 2004, SPIE Astronomical Telescopes + Instrumentation.

[3]  M. Halpern,et al.  Functional Description of Read-out Electronics for Time-Domain Multiplexed Bolometers for Millimeter and Sub-millimeter Astronomy , 2008 .

[4]  Peter A. R. Ade,et al.  A 350-GHz high-resolution high-sensitivity passive video imaging system , 2010, Defense + Commercial Sensing.

[5]  Mikko Leivo,et al.  Stand-off passive THz imaging at 8-meter stand-off distance: results from a 64-channel real-time imager , 2009, Defense + Commercial Sensing.

[6]  Peter A. R. Ade,et al.  SCUBA-2: a large-format submillimeter camera on the James Clerk Maxwell Telescope , 2003, SPIE Astronomical Telescopes + Instrumentation.

[7]  Christian Enss,et al.  Cryogenic particle detection , 2005 .

[8]  J. A. Bonetti,et al.  The BICEP2 CMB polarization experiment , 2010, Astronomical Telescopes + Instrumentation.

[9]  Giampaolo Pisano,et al.  A review of metal mesh filters , 2006, SPIE Astronomical Telescopes + Instrumentation.

[10]  K. Irwin.  An application of electrothermal feedback for high resolution cryogenic particle detection , 1995 .

[11]  Peter A. R. Ade,et al.  Thermal filtering for large aperture cryogenic detector arrays , 2006, SPIE Astronomical Telescopes + Instrumentation.

[12]  Arttu Luukanen,et al.  A superconducting antenna-coupled hot-spot microbolometer , 2003 .

[13]  Mikko Leivo,et al.  Real-time passive terahertz imaging system for standoff concealed weapons imaging , 2010, Defense + Commercial Sensing.

[14]  Mikko Leivo,et al.  Passive terahertz camera for standoff security screening. , 2010, Applied optics.

[15]  J. Zmuidzinas.  Thermal noise and correlations in photon detection. , 2003, Applied optics.

[16]  G. Hilton,et al.  Time-division superconducting quantum interference device multiplexer for transition-edge sensors , 2003 .

[17]  Kent D. Irwin,et al.  Digital readouts for large microwave low-temperature detector arrays , 2006 .

[18]  Christopher J. Mann.  First demonstration of a vehicle mounted 250GHz real time passive imager , 2009, Defense + Commercial Sensing.

[19]  R Appleby,et al.  Passive millimetre–wave imaging and how it differs from terahertz imaging , 2004, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[20]  R. Dicke.  The measurement of thermal radiation at microwave frequencies. , 1946, The Review of scientific instruments.

[21]  M. Leivo,et al.  THz microbolometers for imaging applications , 2008, 2008 33rd International Conference on Infrared, Millimeter and Terahertz Waves.

[22]  Erik Heinz,et al.  Progress report on Safe VISITOR: approaching a practical instrument for terahertz security screening , 2010, Defense + Commercial Sensing.

[23]  Peter A. R. Ade,et al.  An Optical System for Body Imaging from a Distance Using Near-TeraHertz Frequencies , 2008 .

[24]  E. Brown,et al.  Millimeter-wave, terahertz, and mid-infrared transmissionthrough common clothing , 2004 .

[25]  M. Supanich,et al.  A high capacity completely closed-cycle 250 mK 3He refrigeration system based on a pulse tube cooler , 2004 .

[26]  M. Halpern,et al.  Instrument design and characterization of the Millimeter Bolometer Array Camera on the Atacama Cosmology Telescope , 2008, Astronomical Telescopes + Instrumentation.

[27]  Adrian T. Lee,et al.  A superconducting bolometer with strong electrothermal feedback , 1996 .