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Focused fluorescence excitation with time-reversed ultrasonically encoded light and imaging in thick scattering media

Lai, Puxiang and Suzuki, Yuta and Xu, Xiao and Wang, Lihong V. (2013) Focused fluorescence excitation with time-reversed ultrasonically encoded light and imaging in thick scattering media. Laser Physics Letters, 10 (7). Art. No. 075604. ISSN 1612-2011. PMCID PMC3900304. doi:10.1088/1612-2011/10/7/075604.

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Scattering dominates light propagation in biological tissue, and therefore restricts both resolution and penetration depth in optical imaging within thick tissue. As photons travel into the diffusive regime, typically 1 mm beneath human skin, their trajectories transition from ballistic to diffusive due to the increased number of scattering events, which makes it impossible to focus, much less track, photon paths. Consequently, imaging methods that rely on controlled light illumination are ineffective in deep tissue. This problem has recently been addressed by a novel method capable of dynamically focusing light in thick scattering media via time reversal of ultrasonically encoded (TRUE) diffused light. Here, using photorefractive materials as phase conjugate mirrors, we show a direct visualization and dynamic control of optical focusing with this light delivery method, and demonstrate its application for focused fluorescence excitation and imaging in thick turbid media. These abilities are increasingly critical for understanding the dynamic interactions of light with biological matter and processes at different system levels, as well as their applications for biomedical diagnosis and therapy.

Item Type:Article
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URLURL TypeDescription CentralArticle
Wang, Lihong V.0000-0001-9783-4383
Additional Information:© 2013 Astro Ltd. Received 27 February 2013; Accepted for publication 11 March 2013; Published 15 May 2013. We would like to thank Nitto Denko Technical (Oceanside, CA, USA) for providing the photorefractive polymer for this research. This work was sponsored in part by the National Academies Keck Futures Initiative grant IS 13 and National Institute of Health grants DP1 EB016986 (NIH Director's Pioneer Award), R01 EB000712 and U54 CA136398.
Funding AgencyGrant Number
National Academies Keck Futures InitiativeIS 13
NIHDP1 EB016986
NIHR01 EB000712
NIHU54 CA136398
Issue or Number:7
PubMed Central ID:PMC3900304
Record Number:CaltechAUTHORS:20160727-094611789
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Official Citation:Puxiang Lai et al 2013 Laser Phys. Lett. 10 075604
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:69240
Deposited By: Tony Diaz
Deposited On:27 Jul 2016 17:02
Last Modified:11 Nov 2021 04:11

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