|Time-Reversed Wave Propagation|
Hidden messages recorded backwards on a phonograph record could be deciphered by playing the record on a reversed turntable. However, the science and technology of playing sounds, or electromagnetic waves, backwards in time turns out to be far more interesting than any of those old backmasked messages on Beatles albums. Exploiting time-reversal invariance of the lossless wave equation leads to some surprising effects and is enabling remarkable new technologies. The forward/backward symmetry of wave propagation is exploited in a device known as a “time-reversal mirror.” Such devices actually operate best under conditions where the waves are strongly and randomly scattered, making time-reversed wave propagation of great practical utility. Furthermore, the time-reversed waves can be made to collapse in a very brief time interval and in a very localized manner in space. Here we give an overview of the science and technology of this remarkable symmetry of nature, including development of a new sensor paradigm for detecting changes in complex environments, directed wireless communication, and wireless power transfer.
This work is done in collaboration with Profs. Ed Ott and Tom Antonsen, as well as Gemstone team TESLA, of the University of Maryland and is supported by the IC Post-Doc program, as well as AFOSR and ONR.
Alice and Bob Go Nonlinear! A Synopsis of our work on the APS Physics web site
Synthetic sona movie. This movie illustrates the improvement in a time-reversed collapsing waveform (bottom trace at 9.025 us) as more short orbits are added to the synthetic sona (top trace). See the paper “Focusing Waves at an Arbitary Location in a Ray-Chaotic Enclosure Using Time-Reversed Synthetic Sonas” listed below.
Gemstone Team TESLA is investigating nonlinear time-reversal of electromagnetic waves as a wireless power transfer technology.
Papers: (All papers can be downloaded from the full publication list)
Steven M. Anlage, John Rodgers, Sameer Hemmady, James Hart, Thomas M. Antonsen, Edward Ott, "New Results in Chaotic Time-Reversed Electromagnetics: High Frequency One-Recording-Channel Time Reversal Mirror," Acta Physica Polonica A 112, 569 (2007). pdfBiniyam Tesfaye Taddese, Michael Johnson, James Hart, Thomas Antonsen, Edward Ott, Steven M. Anlage, “Chaotic Time-Reversed Acoustics: Sensitivity of the Loschmidt Echo to Perturbations,”Acta Physica Polonica A, 116, 729-732 (2009). pdf
Biniyam Tesfaye Taddese, James Hart , Thomas M. Antonsen, Edward Ott, and Steven M. Anlage, “Sensor Based on Extending the Concept of Fidelity to Classical Waves,” Appl. Phys. Lett. 95 , 114103 (2009). pdf
Sun K. Hong, Biniyam T. Taddese, Zachary B. Drikas, Steven M. Anlage, Tim D. Andreadis, “Focusing an arbitrary RF pulse at a distance using time-reversal techniques,” J. Electromag. Waves and Apps. 27, 1262-1275 (2013). pdf
Biniyam T. Taddese, Gabriele Gradoni, Franco Moglie, Thomas M Antonsen, Edward Ott, Steven Mark Anlage, “Quantifying Volume Changing Perturbations in a Wave Chaotic System,” New J. Phys. 15, 023025 (2013). pdf
Bo Xiao, Thomas M. Antonsen, Edward Ott, and Steven M. Anlage, “Focusing Waves at an Arbitary Location in a Ray-Chaotic Enclosure Using Time-Reversed Synthetic Sonas.” Phys. Rev. E 93, 052205 (2016). pdf
Frank Cangialosi, Tyler Grover, Patrick Healey, Tim Furman, Andrew Simon and Steven M. Anlage, “Time Reversed Electromagnetic Wave Propagation as a Novel Method of Wireless Power Transfer,” 2016 IEEE Wireless Power Transfer Conference (WPTC), pp. 1 – 4 (2016). pdf
Scott Roman, Rahul Gogna, Steven M. Anlage, “Selective Collapse of Nonlinear Time Reversed Electromagnetic Waves,” 2016 IEEE Wireless Power Transfer Conference (WPTC), pp. 1 – 4 (2016). pdf
|Gemstone Team TESLA|
|Team TESLA Junior Colloquium, Fall 2014|
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