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Grueneisen Relaxation Photoacoustic Microscopy

Wang, Lidai and Zhang, Chi and Wang, Lihong V. (2014) Grueneisen Relaxation Photoacoustic Microscopy. Physical Review Letters, 113 (17). Art. No. 174301. ISSN 0031-9007. PMCID PMC4287460. doi:10.1103/PhysRevLett.113.174301.

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The temperature-dependent property of the Grueneisen parameter has been employed in photoacoustic imaging mainly to measure tissue temperature. Here we explore this property using a different approach and develop Grueneisen relaxation photoacoustic microscopy (GR-PAM), a technique that images nonradiative absorption with confocal optical resolution. GR-PAM sequentially delivers two identical laser pulses with a microsecond-scale time delay. The first laser pulse generates a photoacoustic signal and thermally tags the in-focus absorbers. When the second laser pulse excites the tagged absorbers within the thermal relaxation time, a photoacoustic signal stronger than the first one is produced, owing to the temperature dependence of the Grueneisen parameter. GR-PAM detects the amplitude difference between the two colocated photoacoustic signals, confocally imaging the nonradiative absorption. We greatly improved axial resolution from 45 μm to 2.3 μm and, at the same time, slightly improved lateral resolution from 0.63 μm to 0.41 μm. In addition, the optical sectioning capability facilitates the measurement of the absolute absorption coefficient without fluence calibration.

Item Type:Article
Related URLs:
URLURL TypeDescription Material CentralArticle
Zhang, Chi0000-0002-1324-2311
Wang, Lihong V.0000-0001-9783-4383
Additional Information:© 2014 American Physical Society. Received 16 April 2014; published 20 October 2014. The authors appreciate Professor James Ballard’s help with editing the manuscript, and thank Dr. Amos Danielli, Junjie Yao, Lijun Ma, Arie Krumholz, and Yan Liu for constructive discussions and experimental assistance. This work was sponsored by NIH Grants No. DP1 EB016986 (NIH Director’s Pioneer Award), No. R01 CA186567 (NIH Director’s Transformative Research Award), and No. R01 CA159959.
Funding AgencyGrant Number
NIHDP1 EB016986
NIHR01 CA186567
NIHR02 CA159959
Issue or Number:17
Classification Code:PACS: 43.35.Ud, 42.82.Bq
PubMed Central ID:PMC4287460
Record Number:CaltechAUTHORS:20160616-082234182
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67965
Deposited By: Tony Diaz
Deposited On:16 Jun 2016 21:38
Last Modified:11 Nov 2021 03:57

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