Abstract

We describe the construction and performance of a passive, real-time terahertz camera based on a modular, 64-element linear array of cryogenic hotspot microbolometers. A reflective conical scanner sweeps out a 2m×4m (vertical×horizontal) field of view (FOV) at a standoff range of 8m. The focal plane array is cooled to 4K in a closed cycle refrigerator, and the signals are detected on free-standing bridges of superconducting Nb or NbN at the feeds of broadband planar spiral antennas. The NETD of the focal-plane array, referred to the target plane and to a frame rate of 5s1, is 1.25K near the center of the array and 2K overall.

© 2010 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. Appleby and H. B. Wallace, “Standoff detection of weapons and contraband in the 100GHz to 1THz region,” IEEE Trans. Antennas Propag. 55, 2944–2956 (2007).
    [CrossRef]
  2. C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.
  3. C. Mann, “A compact real time passive terahertz imager,” Proc. SPIE 6211, 6211–6214 (2006).
  4. T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).
  5. A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
    [CrossRef]
  6. A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).
  7. E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).
  8. E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).
  9. J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
    [CrossRef]
  10. A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).
  11. A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).
  12. C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).
  13. A. Luukanen and J. P. Pekola, “A Superconducting antenna-coupled hot-spot microbolometer,” Appl. Phys. Lett. 82, 3970–3972 (2003).
    [CrossRef]
  14. In superconductors, κ consists of contributions by the lattice phonons and the electron-like excitations called “quasiparticles”. The quasiparticle contribution falls exponentially below Tc, while the lattice thermal conductivity is proportional to T3. However, the pairing of normal metals to Cooper pairs results to a decrease of electron–phonon scattering, which can result in an increase in the lattice (phonon) thermal conductivity. Thus, the behavior of κ(T) is very material dependent and beyond the scope of this paper.
  15. H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
    [CrossRef]
  16. D. P. Neikirik and D. B. Rutledge, “Air-bridge microbolometer for far-infrared detection,” Appl. Phys. Lett. 44, 153–155 (1984).
    [CrossRef]
  17. K. D. Irwin, “An application of electrothermal feedback for high resolution cryogenic particle detection,” Appl. Phys. Lett. 66, 1998–2000 (1995).
    [CrossRef]
  18. J. C. Mather, “Bolometer noise: nonequilibrium theory,” Appl. Opt. 21, 1125–1129 (1982).
    [CrossRef] [PubMed]
  19. J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
    [CrossRef]
  20. D. B. Rutledge, D. P. Neikirk, and D. P. Kasilingham, “Integrated circuit antennas,” in Infrared and Millimeter Waves, Vol. 10, K.J.Button, ed. (Academic, 1983), pp. 1–90.
  21. C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).
  22. A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.
  23. D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).
  24. E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
    [CrossRef]
  25. D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.
  26. N. M. Vaidya and T. Williams, “A novel approach to automatic threat detection in mmw imagery of people scanned in portals,” Proc. SPIE 6948, 69480F-1 (1008).
  27. J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
    [CrossRef]
  28. C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
    [CrossRef]
  29. A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

2009

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

2008

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
[CrossRef]

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

2007

R. Appleby and H. B. Wallace, “Standoff detection of weapons and contraband in the 100GHz to 1THz region,” IEEE Trans. Antennas Propag. 55, 2944–2956 (2007).
[CrossRef]

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

2006

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

C. Mann, “A compact real time passive terahertz imager,” Proc. SPIE 6211, 6211–6214 (2006).

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

2004

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

2003

A. Luukanen and J. P. Pekola, “A Superconducting antenna-coupled hot-spot microbolometer,” Appl. Phys. Lett. 82, 3970–3972 (2003).
[CrossRef]

2000

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

1998

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

1997

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

1995

K. D. Irwin, “An application of electrothermal feedback for high resolution cryogenic particle detection,” Appl. Phys. Lett. 66, 1998–2000 (1995).
[CrossRef]

1984

D. P. Neikirik and D. B. Rutledge, “Air-bridge microbolometer for far-infrared detection,” Appl. Phys. Lett. 44, 153–155 (1984).
[CrossRef]

1982

1008

N. M. Vaidya and T. Williams, “A novel approach to automatic threat detection in mmw imagery of people scanned in portals,” Proc. SPIE 6948, 69480F-1 (1008).

Ala-Laurinaho, J.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Ala-Laurinho, J.

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

Anders, S.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Appleby, R.

R. Appleby and H. B. Wallace, “Standoff detection of weapons and contraband in the 100GHz to 1THz region,” IEEE Trans. Antennas Propag. 55, 2944–2956 (2007).
[CrossRef]

Bjaranason, J. E.

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

Bjarnason, J.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Bjarnason, J. E.

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

Brown, E. R.

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

Celis, M. A.

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

Chan, T. L.

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

Chisum, J.

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

Chisum, J. D.

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

D., C. R.

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

Dietlein, C.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

Dietlein, C. R.

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
[CrossRef]

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Filipovic, D. F.

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

Floet, D. W.

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

G., L.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Gauthier, G. P.

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

Gronberg, L.

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Gronholm, M.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Grossman, E.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Grossman, E. N.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
[CrossRef]

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

Haarnoja, T.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Hall, T. E.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Hatchell, B. K.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Helisto, P.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

Helistö, P.

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

Irwin, K. D.

K. D. Irwin, “An application of electrothermal feedback for high resolution cryogenic particle detection,” Appl. Phys. Lett. 66, 1998–2000 (1995).
[CrossRef]

Kasilingham, D. P.

D. B. Rutledge, D. P. Neikirk, and D. P. Kasilingham, “Integrated circuit antennas,” in Infrared and Millimeter Waves, Vol. 10, K.J.Button, ed. (Academic, 1983), pp. 1–90.

Kataja, K.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Khosropanah, P.

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

Kollberg, E. L.

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

Kreysa, E.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Lagarias, J. C.

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

Lappalainen, P.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Lee, A. W.

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

Leivo, M.

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Luukanen, A.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

A. Luukanen and J. P. Pekola, “A Superconducting antenna-coupled hot-spot microbolometer,” Appl. Phys. Lett. 82, 3970–3972 (2003).
[CrossRef]

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

Mallat, J.

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

Mann, C.

C. Mann, “A compact real time passive terahertz imager,” Proc. SPIE 6211, 6211–6214 (2006).

Mather, J. C.

May, T.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

McMakin, D. L.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Merkel, H.

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

Meyer, F.

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

Meyer, H.-G.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Miller, A. J.

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

Neikirik, D. P.

D. P. Neikirik and D. B. Rutledge, “Air-bridge microbolometer for far-infrared detection,” Appl. Phys. Lett. 44, 153–155 (1984).
[CrossRef]

Neikirk, D. P.

D. B. Rutledge, D. P. Neikirk, and D. P. Kasilingham, “Integrated circuit antennas,” in Infrared and Millimeter Waves, Vol. 10, K.J.Button, ed. (Academic, 1983), pp. 1–90.

Pekola, J. P.

A. Luukanen and J. P. Pekola, “A Superconducting antenna-coupled hot-spot microbolometer,” Appl. Phys. Lett. 82, 3970–3972 (2003).
[CrossRef]

Pentilla, J. S.

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

Penttila, J.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

Penttila, J. P.

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

Penttilä, J. S.

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

Popovic, Z.

C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
[CrossRef]

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

Raisanen, A.

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

Raman, S.

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

Ramirez, M.

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Ramirez, M. D.

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

Rautiainen, A.

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

Rebiez, G. M.

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

Reeds, J. A.

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

Rutledge, D. B.

D. P. Neikirik and D. B. Rutledge, “Air-bridge microbolometer for far-infrared detection,” Appl. Phys. Lett. 44, 153–155 (1984).
[CrossRef]

D. B. Rutledge, D. P. Neikirk, and D. P. Kasilingham, “Integrated circuit antennas,” in Infrared and Millimeter Waves, Vol. 10, K.J.Button, ed. (Academic, 1983), pp. 1–90.

Seppa, H.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

Seppä, H.

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

Severtsen, R. H.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Sheen, D. M.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Sipola, H.

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

Starkloff, M.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Tamminen, A.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

Taylor, Z.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

Thorwirth, G.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Toivanen, H.

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

Vaidya, N. M.

N. M. Vaidya and T. Williams, “A novel approach to automatic threat detection in mmw imagery of people scanned in portals,” Proc. SPIE 6948, 69480F-1 (1008).

Valdez, P. L. J.

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

Wallace, H. B.

R. Appleby and H. B. Wallace, “Standoff detection of weapons and contraband in the 100GHz to 1THz region,” IEEE Trans. Antennas Propag. 55, 2944–2956 (2007).
[CrossRef]

Williams, T.

N. M. Vaidya and T. Williams, “A novel approach to automatic threat detection in mmw imagery of people scanned in portals,” Proc. SPIE 6948, 69480F-1 (1008).

Wright, M. H.

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

Wright, P. E.

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

Yagoubov, P. A.

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

Zakosarenko, V.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Zieger, G.

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

Appl Optics

C. R. Dietlein, Z. Popovic, and E. N. Grossman, “Aqueous blackbody calibration source for millimeter-wave/terahertz metrology,” Appl Optics 47, 5604–5615 (2008).
[CrossRef]

Appl. Opt.

Appl. Phys. Lett.

A. Luukanen and J. P. Pekola, “A Superconducting antenna-coupled hot-spot microbolometer,” Appl. Phys. Lett. 82, 3970–3972 (2003).
[CrossRef]

J. E. Bjarnason, T. L. Chan, A. W. Lee, M. A. Celis, and E. R. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[CrossRef]

D. P. Neikirik and D. B. Rutledge, “Air-bridge microbolometer for far-infrared detection,” Appl. Phys. Lett. 44, 153–155 (1984).
[CrossRef]

K. D. Irwin, “An application of electrothermal feedback for high resolution cryogenic particle detection,” Appl. Phys. Lett. 66, 1998–2000 (1995).
[CrossRef]

IEEE Microw. Wirel. Compon. Lett.

A. Luukanen, E. N. Grossman, A. J. Miller, P. Helistö, J. S. Penttilä, H. Sipola, and H. Seppä, “An ultra-low noise superconducting antenna-coupled microbolometer with a room-temperature read-out,” IEEE Microw. Wirel. Compon. Lett. 16, 464–466 (2006).
[CrossRef]

IEEE Trans. Antennas Propag.

R. Appleby and H. B. Wallace, “Standoff detection of weapons and contraband in the 100GHz to 1THz region,” IEEE Trans. Antennas Propag. 55, 2944–2956 (2007).
[CrossRef]

IEEE Trans. Microwave Theor. Tech.

E. N. Grossman, C. R. Dietlein, M. Leivo, A. Rautiainen, and A. Luukanen, “A passive, real-time, terahertz camera for security screening, using superconducting microbolometers,” IEEE Trans. Microwave Theor. Tech. , 1453–1456 (2009).

IEEE Trans. Microwave Theory Tech.

D. F. Filipovic, G. P. Gauthier, S. Raman, and G. M. Rebiez, “Off-axis properties of silicon and quartz dielectric lens antennas,” IEEE Trans. Microwave Theory Tech. 45, 760–766 (1997).

H. Merkel, P. Khosropanah, D. W. Floet, P. A. Yagoubov, and E. L. Kollberg, “Conversion gain and fluctuation noise of phonon-cooled hot-electron bolometers in hot-spot regime,” IEEE Trans. Microwave Theory Tech. 48, 690–699 (2000).
[CrossRef]

International Microwave Symposium Digest

C. R. Dietlein, J. D. Chisum, M. D. Ramirez, A. Luukanen, E. N. Grossman, and Z. Popovic, “Integrated Microbolometer Antenna Characterization from 95–650GHz,” International Microwave Symposium Digest , 1165–1168 (2007).

Proc. SPIE

E. N. Grossman, C. R. Dietlein, J. E. Bjarnason, M. D. Ramirez, M. Leivo, J. Penttila, P. Helisto, and A. Luukanen, “Imaging with modular linear arrays of cryogenic nb microbolometers,” Proc. SPIE 6948, 694806 (2008).
[CrossRef]

D. M. Sheen, T. E. Hall, R. H. Severtsen, D. L. McMakin, B. K. Hatchell, and P. L. J. Valdez, “Active Wideband 350GHz Imaging system for concealed weapon detection,” Proc. SPIE 7309, 73090-I, 2009.

N. M. Vaidya and T. Williams, “A novel approach to automatic threat detection in mmw imagery of people scanned in portals,” Proc. SPIE 6948, 69480F-1 (1008).

E. N. Grossman, C. R. D., J. Chisum, A. Luukanen, J. E. Bjaranason, and E. R. Brown, “Spectral decomposition of ultra-wideband terahertz imagery,” Proc. SPIE 6548, 654807-1–8 (2007).

A. Luukanen, L. G., T. Haarnoja, P. Helisto, K. Kataja, M. Leivo, A. Rautiainen, J. Penttila, J. Bjarnason, C. Dietlein, M. Ramirez, and E. Grossman, “Passive THz Imaging system for stand-off identification of concealed objects: results from a turn-key 16 pixel imager,” Proc. SPIE 6948, 6948-O(2008).

C. Mann, “A compact real time passive terahertz imager,” Proc. SPIE 6211, 6211–6214 (2006).

T. May, G. Zieger, S. Anders, V. Zakosarenko, M. Starkloff, H.-G. Meyer, G. Thorwirth, and E. Kreysa, “Passive standoff terahertz imaging with 1Hz frame rate,” Proc. SPIE 6949, 69490C-1 (2008).

A. Luukanen, L. Gronberg, P. Helisto, J. Penttila, H. Seppa, H. Sipola, C. R. Dietlein, and E. N. Grossman, “Passive euro-american terahertz camera (peat-cam): passive indoor thz imaging at video rates for security applications,” Proc. SPIE 6548, 65480M (2007).

A. Luukanen, P. Helisto, P. Lappalainen, M. Leivo, A. Rautiainen, H. Toivanen, H. Seppa, Z. Taylor, C. R. Dietlein, and E. N. Grossman, “Stand-off Passive THz Imaging at 8-meter standoff distance: results from a 64-channel real-time imager,” Proc. SPIE 7309, 73090F-1 (2009).

C. Dietlein, A. Luukanen, J. S. Pentilla, H. Sipola, L. Gronberg, H. Seppa, P. Helisto, and E. N. Grossman, “Performance Comparison of Nb and NbN Antenna-coupled Microbolometers,” Proc. SPIE 6549, 65490-M (2007).

SIAM J. Optimization

J. C. Lagarias, J. A. Reeds, M. H. Wright, and P. E. Wright, “Convergence properties of the nelder-mead simplex method in low dimensions,” SIAM J. Optimization 9, 112–147, 1998.
[CrossRef]

Supercond. Sci. Technol.

J. P. Penttila, H. Sipola, P. Helisto, and H. Seppa, “Low-noise readout of superconducting bolometers based on electrothermal feedback,” Supercond. Sci. Technol. 19, 319–322 (2006).
[CrossRef]

Other

D. B. Rutledge, D. P. Neikirk, and D. P. Kasilingham, “Integrated circuit antennas,” in Infrared and Millimeter Waves, Vol. 10, K.J.Button, ed. (Academic, 1983), pp. 1–90.

C. R. Dietlein, A. Luukanen, F. Meyer, Z. Popovic, and E. N. Grossman, “Phenomenology of passive broadband terahertz images,” in 4th ESA Workshop on Millimetre-wave Technology and Applications (2006), pp. 405–410.

A. Tamminen, J. Ala-Laurinho, J. Mallat, A. Luukanen, E. N. Grossman, and A. Raisanen, “Characterization of Antenna-coupled Microbolometers for THz Imaging,” presented at the 5th ESA Workshop on Millimetre Wave Technology and Applications and 31st ESA Antenna Workshop, ESTEC, Netherlands, 2009.

In superconductors, κ consists of contributions by the lattice phonons and the electron-like excitations called “quasiparticles”. The quasiparticle contribution falls exponentially below Tc, while the lattice thermal conductivity is proportional to T3. However, the pairing of normal metals to Cooper pairs results to a decrease of electron–phonon scattering, which can result in an increase in the lattice (phonon) thermal conductivity. Thus, the behavior of κ(T) is very material dependent and beyond the scope of this paper.

A. Luukanen, L. Gronberg, M. Gronholm, P. Lappalainen, M. Leivo, A. Tamminen, J. Ala-Laurinaho, C. R. Dietlein, and E. N. Grossman, “Real-time passive terahertz imaging system for standoff concealed weapons imaging,” Proc. SPIE (to be published).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (18)

Fig. 1
Fig. 1

SEM images of microbolometers used in the camera: (left) NbN with Al antenna and (right) Nb with Au antenna. Note the difference in scales.

Fig. 2
Fig. 2

Current–voltage characteristics of Nb (left) and NbN (right) hotspot microbolometers used in the camera’s focal plane array. At the top, 20 I-V curves (for each material) are plotted together to illustrate detector uniformity and large-scale DC properties. At center, the scale of the current axis is greatly expanded near the minimum of current (the operating region), for the median detector in the ensemble. At bottom, I-V curves are shown for individual detectors of each material that exhibit a common type of non-ideal feature.

Fig. 3
Fig. 3

Theoretical I-V curves, from Eq. (3), simulating the effect of a 10% reduction in P sat (corresponding to 0.3 K suppression of T c ) in the outer edges of the bridge. The boundary between the 2 regions lies at a fractional bridge length x / l .

Fig. 4
Fig. 4

Low-noise transimpedance readout circuit, first stage (upper) and second stage (lower) of a single channel.

Fig. 5
Fig. 5

Current noise spectral densities for typical detectors of each material, at their optimal bias points.

Fig. 6
Fig. 6

Exploded view of 1 × 8 detector module.

Fig. 7
Fig. 7

Monchromatic 654 GHz antenna pattern, measured at 300 K (at VTT). Grayscale is in dB.

Fig. 8
Fig. 8

Experimental configuration for measurement of broadband antenna pattern.

Fig. 9
Fig. 9

Broadband antenna patterns measured on a Nb detector module. At top, comparison of the 8 individual patterns, plotted on the same scale (x and y dimensions in degrees). At bottom left, a single pattern at an expanded scale, and, at right, residual from the best Gaussian fit to it.

Fig. 10
Fig. 10

Encircled energy plot for 24 detectors from 4 modules (separate modules, color-coded online).

Fig. 11
Fig. 11

Measured beam locations in the directions orthogonal to (upper) and parallel to (lower) the FPA, for versus detector location in the focal plane.

Fig. 12
Fig. 12

Physical layout of the overall system and a photograph of the assembled system at NIST.

Fig. 13
Fig. 13

Histogram (measured at VTT) of the fitted minor axis FWHMs across the FOV, with a mean and median of 0.67 ° and 0.64 ° , respectively. The peak of the distribution is at 0.56 ° .

Fig. 14
Fig. 14

Block diagram of the timing and data acquisition system.

Fig. 15
Fig. 15

NETD (referred to the target plane) of individual detectors across the array, referred to the 5 fps frame rate.

Fig. 16
Fig. 16

NETD distribution after coordinate transformation to image pixels (spatial map and histogram).

Fig. 17
Fig. 17

Image of one of the authors at 8 m range.

Fig. 18
Fig. 18

Drift in gains of all detector channels. Note the logarithmic time axis. The initial calibration was performed at t = 100 s . Heavy dashed lines indicate ± 50 % drift over 10 min.

Tables (3)

Tables Icon

Table 1 Noise Parameters of Typical Nb and NbN Microbolometers, Measured at Their Optimal Bias Points

Tables Icon

Table 2 Spatial Sampling

Tables Icon

Table 3 Scanner Properties

Equations (7)

Equations on this page are rendered with MathJax. Learn more.

κ d 2 T d x 2 + P o Al n + V 2 ρ l n 2 = 0 , | x | < l n , κ d 2 T d x 2 = 0 , l n < | x | l .
I = V / R n { 1 + 2 [ ( p o + p e 1 ) + ( p o + p e + 1 ) 2 4 p o ] 1 } = V R n + P sat V for p o = 0 ,
E I = d I d P o = 2 p e V [ ( p o + p e + 1 ) 2 4 p o + ( p o + p e 1 ) ( p o + p e + 1 ) 2 4 p o ] 1 = 1 V ( p e + 1 ) for p o 0.
S I = S a ( d I d V ) 2 + 4 k T eff j I V [ V 4 ( V 2 + V min 2 ) 2 ] + 4 k T eff p 2 G eff E I 2 = S a ( d I d V ) 2 + 4 k T eff j I V [ V 4 ( V 2 + V min 2 ) 2 ] + 4 k T eff p 2 G eff [ V min 4 V 2 ( V 2 + V min 2 ) 2 ] ,
S I = 2 k T eff j R n + k T eff p 2 G eff R n P s = 2 k T eff j R n + k T eff p 2 R n ( T c T 0 ) .
x = R ( 1 + 1 / n ) sin ( θ / n ) 60 μm .
M i j = m , n W i j m n D m n

Metrics