Optical-resolution photoacoustic microscopy with ultrafast dual-wavelength excitation

Yingying Zhou, Siyi Liang, Mingsheng Li, Chengbo Liu, Puxiang Lai (Corresponding Author), Lidai Wang (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)

Abstract

Fast functional and molecular photoacoustic microscopy requires pulsed laser excitations at multiple wavelengths with enough pulse energy and short wavelength-switching time. Recent development of stimulated Raman scattering in optical fiber offers a low-cost laser source for multiwavelength photoacoustic imaging. In this approach, long fibers temporally separate different wavelengths via optical delay. The time delay between adjacent wavelengths may eventually limits the highest A-line rate. In addition, a long-time delay in fiber may limit the highest pulse energy, leading to poor image quality. In order to achieve high pulse energy and ultrafast dual-wavelength excitation, we present optical-resolution photoacoustic microscopy with ultrafast dual-wavelength excitation and a signal separation method. The signal separation method is validated in numerical simulation and phantom experiments. We show that when two photoacoustic signals are partially overlapped with a 50-ns delay, they can be recovered with 98% accuracy. We apply this ultrafast dual-wavelength excitation technique to in vivo OR-PAM. Results demonstrate that A-lines at two wavelengths can be successfully separated, and sO2 values can be reliably computed from the separated data. The ultrafast dual-wavelength excitation enables fast functional photoacoustic microscopy with negligible misalignment among different wavelengths and high pulse energy, which is important for in vivo imaging of microvascular dynamics.

Original languageEnglish
Article numbere201960229
JournalJournal of Biophotonics
Volume13
Issue number6
DOIs
Publication statusPublished - 1 Jun 2020

Keywords

  • fast dual-wavelength excitation
  • functional photoacoustic imaging
  • multiwavelength
  • signal separation

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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