High-speed time-reversed ultrasonically encoded (TRUE) optical focusing inside dynamic scattering media at 793 nm

Yan Liu, Puxiang Lai, Cheng Ma, Xiao Xu, Yuta Suzuki, Alexander A. Grabar, Lihong V. Wang

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

2 Citations (Scopus)


Time-reversed ultrasonically encoded (TRUE) optical focusing is an emerging technique that focuses light deep into scattering media by phase-conjugating ultrasonically encoded diffuse light. In previous work, the speed of TRUE focusing was limited to no faster than 1 Hz by the response time of the photorefractive phase conjugate mirror, or the data acquisition and streaming speed of the digital camera; photorefractive-crystal-based TRUE focusing was also limited to the visible spectral range. These time-consuming schemes prevent this technique from being applied in vivo, since living biological tissue has a speckle decorrelation time on the order of a millisecond. In this work, using a Tedoped Sn2P2S6 photorefractive crystal at a near-infrared wavelength of 793 nm, we achieved TRUE focusing inside dynamic scattering media having a speckle decorrelation time as short as 7.7 ms. As the achieved speed approaches the tissue decorrelation rate, this work is an important step forward toward in vivo applications of TRUE focusing in deep tissue imaging, photodynamic therapy, and optical manipulation.
Original languageEnglish
Title of host publicationPhotons Plus Ultrasound
Subtitle of host publicationImaging and Sensing 2014
ISBN (Print)9780819498564
Publication statusPublished - 1 Jan 2014
Externally publishedYes
EventPhotons Plus Ultrasound: Imaging and Sensing 2014 - San Francisco, CA, United States
Duration: 2 Feb 20145 Feb 2014


ConferencePhotons Plus Ultrasound: Imaging and Sensing 2014
Country/TerritoryUnited States
CitySan Francisco, CA


  • Light scattering
  • Optical focusing
  • Optical phase conjugation
  • Optical time reversal
  • Time-Reversed Ultrasonically Encoded (TRUE) optical focusing
  • Turbid media

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

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