title: All-optical scanhead for ultrasound and photoacoustic imaging-Imaging mode switching by dichroic filtering.
abstract: Ultrasound (US) and photoacoustic (PA) multimodality imaging has the advantage of combining good acoustic resolution with high optical contrast. The use of an all-optical scanhead for both imaging modalities can simplify integration of the two systems and miniaturize the imaging scanhead. Herein we propose and demonstrate an all-optical US/PA scanhead using a thin plate for optoacoustic generation in US imaging, a polymer microring resonator for acoustic detection, and a dichroic filter to switch between the two imaging modes by changing the laser wavelength. A synthetic-aperture focusing technique is used to improve the resolution and contrast. Phantom images demonstrate the feasibility of this design, and show that axial and lateral resolutions of 125 μm and 2.52°, respectively, are possible.
authors.affiliation: Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Hsieh
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Sung-Liang
authors.initials: SL
authors.lastname: Chen
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Ling
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA.
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Guo
authors.affiliation: Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan ; Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
authors.forename: Pai-Chi
authors.initials: PC
authors.lastname: Li
keywords: All-optical scanhead; Dichroic filtering; Photoacoustic imaging; Ultrasound