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 January 2023 | public
Journal Article

Optical-resolution photoacoustic microscopy with a needle-shaped beam


Optical-resolution photoacoustic microscopy can visualize wavelength-dependent optical absorption at the cellular level. However, this technique suffers from a limited depth of field due to the tight focus of the optical excitation beam, making it challenging to acquire high-resolution images of samples with uneven surfaces or high-quality volumetric images without z scanning. To overcome this limitation, we propose needle-shaped beam photoacoustic microscopy, which can extend the depth of field to around a 28-fold Rayleigh length via customized diffractive optical elements. These diffractive optical elements generate a needle-shaped beam with a well-maintained beam diameter, a uniform axial intensity distribution and negligible sidelobes. The advantage of using needle-shaped beam photoacoustic microscopy is demonstrated via both histology-like imaging of fresh slide-free organs using a 266 nm laser and in vivo mouse-brain vasculature imaging using a 532 nm laser. This approach provides new perspectives for slide-free intraoperative pathological imaging and in vivo organ-level imaging.

Additional Information

L.V.W. was sponsored by the United States National Institutes of Health grants R01 EB028277, U01 NS099717 (BRAIN Initiative) and R35 CA220436 (Outstanding Investigator Award). A.d.l.Z. was supported by the National Institutes of Health grants DP50D012179 and K23CA211793, the United States National Science Foundation (NSF 1438340) and the United States Air Force (FA9550–15–1–0007).

Additional details

August 22, 2023
October 24, 2023