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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Editor: Franco Gori
  • Vol. 29, Iss. 12 — Dec. 1, 2012
  • pp: 2643–2656

Elimination of speckle and target orientation requirements in millimeter-wave active imaging by modulated multimode mixing illumination

Mark A. Patrick, Jennifer A. Holt, Colin D. Joye, and Frank C. De Lucia  »View Author Affiliations

JOSA A, Vol. 29, Issue 12, pp. 2643-2656 (2012)

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Active imaging can provide significantly larger signal margins in the millimeter-wave spectral region than passive imaging, especially indoors—an important application for which there is no cold sky illumination. However, coherent effects, such as speckle, negate much of this advantage by destroying image clarity and target recognition. Moreover, active imaging demonstrations often use strategically chosen target orientations to optimally reflect power from the active illuminator back to the imaging receiver. In this paper we will discuss and show experimental results for a new active imaging approach that largely eliminates coherent effects and the need for optimized target orientation. The work described uses a synthesized harmonic multiplier chain to drive a 5 W extended interaction klystron at 218.4 GHz, a mechanical mode mixer to illuminate and modulate many modes, and a heterodyne receiver coupled into a 60 cm scanning mirror. Large signal margins were obtained in this 50m range work, showing paths to imaging at 1km, imaging with considerably less powerful illuminators, and the use of focal plane arrays.

© 2012 Optical Society of America

OCIS Codes
(030.6140) Coherence and statistical optics : Speckle
(350.4010) Other areas of optics : Microwaves
(110.6795) Imaging systems : Terahertz imaging

ToC Category:
Imaging Systems

Original Manuscript: April 26, 2012
Revised Manuscript: August 29, 2012
Manuscript Accepted: August 31, 2012
Published: November 28, 2012

Mark A. Patrick, Jennifer A. Holt, Colin D. Joye, and Frank C. De Lucia, "Elimination of speckle and target orientation requirements in millimeter-wave active imaging by modulated multimode mixing illumination," J. Opt. Soc. Am. A 29, 2643-2656 (2012)

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  1. S. M. Kulpa and E. A. Brown, Near-Millimeter Wave Technology Base Study (Harry Diamond Laboratories, 1979).
  2. P. W. Kruse, “Why the military interest in near-millimeter wave imaging?” Proc. SPIE 259, 94–97 (1980). [CrossRef]
  3. D. M. Sheen, D. L. McMakin, and T. E. Hall, “Three-dimensional millimeter-wave imaging for concealed weapon detection,” IEEE Trans. Microwave Theor. Tech. 49, 1581–1592 (2001). [CrossRef]
  4. E. N. Grossman, A. Luukanen, and A. J. Miller, “Terahertz active direct detection imagers,” Proc. SPIE 5411, 68–77 (2004). [CrossRef]
  5. A. Luukanen, A. J. Miller, and E. N. Grossman, “Active millimeter-wave video rate imaging with a staring 120-element microbolometer array,” Proc. SPIE 5410, 195–210 (2004). [CrossRef]
  6. D. T. Petkie, C. Casto, F. C. De Lucia, S. R. Murrill, B. Redman, R. L. Espinola, C. C. Franck, E. L. Jacobs, S. T. Griffin, C. E. Halford, J. Reynolds, S. O’Brien, and D. Tofsted, “Active and passive imaging in the THz spectral region: phenomenology, dynamic range, modes, and illumination,” J. Opt. Soc. Am. B 25, 1523–1531 (2008). [CrossRef]
  7. I. Ocket, D. Schreurs, V. Tavakol, F. Qi, B. Nauwelaers, and J. Stiens, “Design challenges for millimeter wave active imaging systems,” in Proceedings of the 7th European Radar Conference (IEEE, 2010), pp. 312–315.
  8. S. Yeom, D.-S. Lee, J.-Y. Son, M.-K. Jung, Y. Jang, S.-W. Jung, and S.-J. Lee, “Real-time outdoor concealed-object detection with passive millimeter wave imaging,” Opt. Express 19, 2530–2536 (2011). [CrossRef]
  9. L. Zhang, J. Stiens, A. Elhawil, and R. Vounckx, “Multispectral illumination and image processing techniques for active millimeter-wave concealed object detection,” Appl. Opt. 47, 6357–6365 (2008). [CrossRef]
  10. I. Jaeger, J. Stiens, L. Zhang, S. Islam, G. Koers, and R. Vounckx, “Comparison of speckle reduction diversity tools for active millimeter-wave imaging,” J. Opt. Soc. Am. A 25, 1716–1721 (2008). [CrossRef]
  11. G. Koers, I. Ocket, Q. Feng, V. Tavakol, I. Jäger, B. Nauwelaers, and J. Stiens, “Study of active millimeter-wave image speckle reduction by Hadamard phase pattern illumination,” J. Opt. Soc. Am. A 25, 312–317 (2008). [CrossRef]
  12. D. N. Bittner, R. L. Crownover, F. C. De Lucia, and S. L. Shostak, “Passive imaging with a broadband cooled detector,” in 12th International Conference on Infrared and Millimeter Waves (IEEE, 1987).
  13. H. B. Wallace, “Analysis of RF imaging applications at frequencies over 100 GHz,” Appl. Opt. 49, E38–E47 (2010). [CrossRef]
  14. Y.-W. Chang and M. Johnson, “Portable concealed weapon detection using millimeter wave FMCW radar imaging,” Proc. SPIE 4232, 134–141 (1998).
  15. W. Caba and G. D. Boreman, “Active sparse-aperture millimeter-wave imaging using digital correlators,” J. Infrared Millim. Terahertz Waves 32, 434–450 (2011). [CrossRef]
  16. C. am Weg, W. von Spiegel, R. Henneberger, R. Zimmermann, T. Loeffler, and H. G. Roskos, “Fast active THz cameras with ranging capabilities,” J. Infrared Millim. Terahertz Waves 30, 1281–1296 (2009).
  17. T. D. Dorney, W. W. Symes, R. G. Baraniuk, and D. M. Mittleman, “Terahertz multistatic reflection imaging,” J. Opt. Soc. Am. 19, 1432–1442 (2002). [CrossRef]
  18. Q. Li, S.-H. Ding, R. Yao, and Q. Wang, “Real-time terahertz scanning imaging by use of a pyroelectric array camera and image denoising,” J. Opt. Soc. Am. 27, 2381–2386 (2010). [CrossRef]
  19. T. W. Du Bosq, J. M. Lopez-Alonso, and G. D. Boreman, “Millimeter wave imaging system for land mine detection,” Appl. Opt. 45, 5686–5692 (2006). [CrossRef]
  20. D. T. Petkie, J. Holt, M. A. Patrick, and F. C. De Lucia, “Multimode illumination in the terahertz for elimination of target orientation requirements and minimization of coherent effects in active imaging systems,” Opt. Eng. 51, 091604 (2012). [CrossRef]
  21. K. B. Cooper, R. J. Denglera, N. Llombartb, A. Talukdera, A. V. Panangadana, C. S. Peaya, I. Mehdia, and P. H. Siegel, “Fast, high-resolution terahertz radar imaging at 25 meters,” Proc. SPIE 7671, 76710Y (2010).
  22. W. B. Lewis, “Fluctuations in streams of thermal radiation,” Proc. Phys. Soc 59, 34–40 (1947). [CrossRef]
  23. E. H. Putley, “The ultimate sensitivity of sub-mm detectors,” Infrared Phys. 4, 1–8 (1964). [CrossRef]
  24. F. C. De Lucia, “Noise, detectors, and submillimeter-terahertz system performance in nonambient environments,” J. Opt. Soc. Am. B 21, 1273–1297 (2004). [CrossRef]
  25. E. Grossman, C. Dietlein, J. Ala-Laurinaho, M. Leivo, L. Gronberg, M. Gronholm, P. Lappalainen, A. Rautiainen, A. Tamminen, and A. Luukanen, “Passive terahertz camera for standoff security screening,” Appl. Opt. 49, E106–E120(2010). [CrossRef]
  26. N. George and A. Jain, “Speckle reduction using multiple tones of illumination,” Appl. Opt. 12, 1202–1212 (1973). [CrossRef]
  27. N. George, A. Jain, and R. D. S. Melville, “Experiments on the space and wavelength dependence of speckle,” Appl. Phys. 7, 157–169 (1975). [CrossRef]
  28. J. W. Goodman, “Dependence of image speckle contrast on surface roughness,” Opt. Commun. 14, 324–327 (1975). [CrossRef]
  29. J. W. Goodman, “Some fundamental properties of speckle,” J. Opt. Soc. Am. 66, 1145–1150 (1976). [CrossRef]
  30. J. W. Goodman, Speckle Phenomena in Optics: Theory and Applications (Roberts, 2007).
  31. N. George, C. R. Christensen, J. S. Bennett, and B. D. Guenther, “Speckle noise in displays,” J. Opt. Soc. Am. 66, 1282–1290 (1976). [CrossRef]
  32. A. Yariv, Quantum Electronics, 2nd ed. (Wiley, 1975).
  33. P. Coward and R. Appleby, “Development of an illumination chamber for indoor millimetre-wave imaging,” Proc. SPIE 5077, 54–61 (2003). [CrossRef]
  34. N. E. Alexander, C. C. Andres, and R. Gonzalo, “Multispectral mm-wave imaging: materials and images,” Proc. SPIE 6948, 694803 (2008). [CrossRef]
  35. F. Qi, V. Tavakol, D. Schreurs, and B. Nauwelaers, “Limitations of approximations towards Fourier optics for indoor active millimeter wave imaging systems,” Prog. Electromagn. Res. 109, 245–262 (2010). [CrossRef]
  36. F. Qi, V. Tavakol, I. Ocket, P. Xu, D. Schreurs, J. Wang, and B. Nauwelaers, “Millimeter wave imaging system modeling: spatial frequency domain calculation versus spatial domain calculation,” J. Opt. Soc. Am. A 27, 131–140 (2010). [CrossRef]

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