For the last 20 years, the time-reversal (TR) process has been successfully applied to focus pulses in the microwave frequency range and in complex media. Here we examine the specific conditions to obtain the same results but in the sub-THz frequency range. Because of the stronger attenuation at this much higher frequency, it is more challenging to exploit the TR self-focusing property. The TR of pulses is studied in two kinds of complex media: metallic waveguide and leaky reverberating cavity. For each medium, we propose one or two models to assess the quality of the focusing. For the waveguide, we show that the angle of incidence is an important parameter. Based on these results, we perform TR experiments at 273 GHz with a bandwidth that can be as large as 2 GHz. TR experiments are successfully first conducted in a 1 m long and 10 mm diameter straight hollow cylinder and then in a 5 m long and 12 mm diameter curved waveguide. Finally, we present results obtained in a cavity of 72 cm3 that leaks through a copper grid. The best focusing is observed with the longer waveguide.
2. Fink, M., "Time reversal of ultrasonic fields. I. Basic principles," IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 39, 555, 1992.
doi:10.1109/58.156174
3. Wu, F., J.-L. Thomas, and M. Fink, "Time reversal of ultrasonic fields. Il. Experimental results," IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 39, 567, 1992.
doi:10.1109/58.156175
4. Derode, A., P. Roux, and M. Fink, "Robust acoustic time reversal with high-order multiple scattering," Physical Review Letters, Vol. 75, 4206, 1995.
doi:10.1103/PhysRevLett.75.4206
5. Roux, P. and M. Fink, "Time-reversal in a waveguide," The Journal of the Acoustical Society of America, Vol. 110, 2631, 2001.
doi:10.1121/1.4776902
6. Draeger, C. and M. Fink, "One-channel time reversal of elastic waves in a chaotic 2D-silicon cavity," Physical Review Letters, Vol. 79, 407, 1997.
doi:10.1103/PhysRevLett.79.407
7. Lerosey, G., J. De Rosny, A. Tourin, A. Derode, G. Montaldo, and M. Fink, "Time reversal of electromagnetic waves," Physical Review Letters, Vol. 92, 193904, 2004.
doi:10.1103/PhysRevLett.92.193904
8. Lerosey, G., J. De Rosny, A. Tourin, A. Derode, and M. Fink, "Time reversal of wideband microwaves," Applied Physics Letters, Vol. 88, 154101, 2006.
doi:10.1063/1.2194009
9. Edelmann, G. F., T. Akal, W. S. Hodgkiss, S. Kim, W. A. Kuperman, and H. C. Song, "An initial demonstration of underwater acoustic communication using time reversal," IEEE Journal of Oceanic Engineering, Vol. 27, 602, 2002.
doi:10.1109/JOE.2002.1040942
10. Hengy, S., P. Hamery, S. De Mezzo, and P. Duffner, "Networked localization of sniper shots using acoustics," SPIE Defense, Security, and Sensing, 804602-804602, International Society for Optics and Photonics, 2011.
11. Pernot, M., J.-F. Aubry, M. Tanter, A.-L. Boch, F. Marquet, M. Kujas, D. Seilhean, and M. Fink, "In vivo transcranial brain surgery with an ultrasonic time reversal mirror," Journal of Neurosurgery, Vol. 106, 1061, 2007.
doi:10.3171/jns.2007.106.6.1061
12. Thomas, J.-L., F. Wu, and M. Fink, "Time reversal focusing applied to lithotripsy," Ultrasonic Imaging, Vol. 18, 106, 1996.
doi:10.1177/016173469601800202
13. Chakroun, N., M. Fink, and F. Wu, "Time reversal processing in ultrasonic nondestructive testing," IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 42, 1087, 1995.
doi:10.1109/58.476552
14. Wang, C. H., J. T. Rose, and F.-K. Chang, "A synthetic time-reversal imaging method for structural health monitoring," Smart Materials and Structures, Vol. 13, 415, 2004.
doi:10.1088/0964-1726/13/2/020
15. Roux, P., A. Derode, A. Peyre, A. Tourin, and M. Fink, "Acoustical imaging through a multiple scattering medium using a time-reversal mirror," The Journal of the Acoustical Society of America, Vol. 107, L7, 2000.
doi:10.1121/1.428602
16. Wang, M., G. Yang, W. Li, and Q. Wu, "An overview of cancer treatment by terahertz radiation," 2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO), IEEE, 2013.
17. Echchgadda, I., J. E. Grundt, C. Z. Cerna, C. C. Roth, J. A. Payne, B. L. Ibey, and G. J. Wilmink, "Terahertz radiation: A non-contact tool for the selective stimulation of biological responses in human cells," IEEE Transactions on Terahertz Science and Technology, Vol. 6, 54, 2016.
doi:10.1109/TTHZ.2015.2504782
18. Cooper, K. B., R. J. Dengler, N. Llombart, B. Thomas, G. Chattopadhyay, and P. H. Siegel, "THz imaging radar for standoff personnel screening," IEEE Transactions on Terahertz Science and Technology, Vol. 1, 169, 2011.
doi:10.1109/TTHZ.2011.2159556
19. Wietzker, S., C. Jordens, N. Krumbholz, B. Baudrit, M. Bastian, and M. Koch, "Terahertz imaging: A new non-destructive technique for the quality control of plastic weld joints," Journal of the European Optical Society: Rapid Publications, Vol. 2, 2007.
doi:10.2971/jeos.2007.07013
20. Song, H.-J. and T. Nagatsuma, "Present and future of terahertz communications," IEEE Transactions on Terahertz Science and Technology, Vol. 1, 256, 2011.
doi:10.1109/TTHZ.2011.2159552
21. Zhang, Y., W. Zhou, X. Wang, Y. Cui, and W. Sun, "Terahertz digital holography," Strain, Vol. 44, 380, 2008.
doi:10.1111/j.1475-1305.2008.00433.x
22. Ruffin, A. B., J. Decker, L. Sanchez-Palencia, L. L. Hors, J. F. Whitaker, T. B. Norris, and J. V. Rudd, "Time reversal and object reconstruction with single-cycle pulses," Optics Letters, Vol. 26, 681, 2001.
doi:10.1364/OL.26.000681
23. Ruffin, A. B., J. V. Rudd, J. Decker, L. Sanchez-Palencia, L. L. Hors, J. F. Whitaker, and T. B. Norris, "Time reversal terahertz imaging," IEEE Journal of Quantum Electronics, Vol. 38, 1110, 2002.
doi:10.1109/JQE.2002.801007
24. Buma, T. and T. B. Norris, "Time reversal three-dimensional imaging using single-cycle terahertz pulses," Applied Physics Letters, Vol. 84, 2196, 2004.
doi:10.1063/1.1686896
25. Lopato, P. and T. Chady, "Time reversal pulsed terahertz inspection of dielectric structures," International Journal of Applied Electromagnetics and Mechanics, Vol. 39, 427, 2012.
doi:10.3233/JAE-2012-1492
26. Musheinesh, M. A., C. J. Divin, J. A. Fessler, and T. B. Norris, "Time-reversal and model-based imaging in a THz waveguide," Optics Express, Vol. 17, 13663, 2009.
doi:10.1364/OE.17.013663
27. Draeger, C. and M. Fink, "One-channel time-reversal in chaotic cavities: Theoretical limits," The Journal of the Acoustical Society of America, Vol. 105, 611, 1999.
doi:10.1121/1.426251
28. Draeger, C., J.-C. Aime, and M. Fink, "One-channel time-reversal in chaotic cavities: Experimental results," The Journal of the Acoustical Society of America, Vol. 105, 618, 1999.
doi:10.1121/1.426252
29. Derode, A., A. Tourin, and M. Fink, "Ultrasonic pulse compression with one-bit time reversal through multiple scattering," Journal of Applied Physics, Vol. 85, 6343, 1999.
doi:10.1063/1.370136
30. Borcea, L., G. Papanicolaou, C. Tsogka, and J. Berryman, "Imaging and time reversal in random media," Inverse Problems, Vol. 18, 1247, 2002.
doi:10.1088/0266-5611/18/5/303
31. Goodman, J., Statistical Optics, Wiley, New York, 2000, ISBN 9780471399162.
32. Montaldo, G., P. Roux, A. Derode, C. Negreira, and M. Fink, "Ultrasound shock wave generator with one-bit time reversal in a dispersive medium, application to lithotripsy," Applied Physics Letters, Vol. 80, 897, 2002.
doi:10.1063/1.1446996
33. Davy, M., J. de Rosny, J.-C. Joly, and M. Fink, "Focusing and amplification of electromagnetic waves by time reversal in an leaky reverberation chamber," Comptes Rendus Physique, Vol. 11, 37, 2010.
doi:10.1016/j.crhy.2009.12.008
34. Dupre, M., M. Fink, and G. Lerosey, "Using subwavelength diffraction gratings to design open electromagnetic cavities," Physical Review Letters, Vol. 112, 043902, 2014.
doi:10.1103/PhysRevLett.112.043902
35. Koenig, S., et al., "Wireless sub-THz communication system with high data rate," Nature Photonics, Vol. 7, 977, 2013.
doi:10.1038/nphoton.2013.275
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