Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 31, 2020 | Published
Journal Article Open

Multifocal photoacoustic microscopy using a single-element ultrasonic transducer through an ergodic relay


Optical-resolution photoacoustic microscopy (OR-PAM) has demonstrated high-spatial-resolution imaging of optical absorption in biological tissue. To date, most OR-PAM systems rely on mechanical scanning with confocally aligned optical excitation and ultrasonic detection, limiting the wide-field imaging speed of these systems. Although several multifocal OR-PA (MFOR-PA) systems have attempted to address this limitation, they are hindered by the complex design in a constrained physical space. Here, we present a two-dimensional (2D) MFOR-PAM system that utilizes a 2D microlens array and an acoustic ergodic relay. Using a single-element ultrasonic transducer, this system can detect PA signals generated from 400 optical foci in parallel and then raster scan the optical foci patterns to form an MFOR-PAM image. This system improves the imaging resolution of an acoustic ergodic relay system from 220 to 13 μm and enables 400-folds shorter scanning time than that of a conventional OR-PAM system at the same resolution and laser repetition rate. We demonstrated the imaging ability of the system with both in vitro and in vivo experiments.

Additional Information

© 2020 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 01 March 2020; Revised 17 July 2020; Accepted 20 July 2020; Published 31 July 2020. The authors appreciate Prof. James Ballard's close reading of the paper. This work was supported in part by National Institutes of Health grants DP1 EB016986 (NIH Director's Pioneer Award), R01 CA186567 (NIH Director's Transformative Research Award), U01 NS090579 (BRAIN1 Initiative) and U01 NS099717 (BRAIN Initiative). Data availability: The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request and with permission from corporate collaborations. Code availability: The reconstruction algorithm and data processing methods are described in detail in the Methods section. We have opted not to make the computer codes publicly available due to corporate collaborations. Author Contributions: Y.L. and T.T.W.W. conceived the concept and designed the study. Y.L. built the imaging system. Y.L. and T.T.W.W. performed the experiments. J.S. developed the data acquisition program. Y.L. and H.-C.H. analysed the data. L.V.W. supervised the project. All authors contributed to the writing of the paper. Conflict of interest: L.V.W. has a financial interest in Microphotoacoustics, Inc., CalPACT, LLC, and Union Photoacoustic Technologies, Ltd., which, however, did not support this work.

Attached Files

Published - s41377-020-00372-x.pdf


Files (1.6 MB)
Name Size Download all
1.6 MB Preview Download

Additional details

August 22, 2023
October 20, 2023