title: Thin polymer etalon arrays for high-resolution photoacoustic imaging.
abstract: Thin polymer etalons are demonstrated as high-frequency ultrasound sensors for three-dimensional (3-D) high-resolution photoacoustic imaging. The etalon, a Fabry-Perot optical resonator, consists of a thin polymer slab sandwiched between two gold layers. It is probed with a scanning continuous-wave (CW) laser for ultrasound array detection. Detection bandwidth of a 20-microm-diam array element exceeds 50 MHz, and the ultrasound sensitivity is comparable to polyvinylidene fluoride (PVDF) equivalents of similar size. In a typical photoacoustic imaging setup, a pulsed laser beam illuminates the imaging target, where optical energy is absorbed and acoustic waves are generated through the thermoelastic effect. An ultrasound detection array is formed by scanning the probing laser beam on the etalon surface in either a 1-D or a 2-D configuration, which produces 2-D or 3-D images, respectively. Axial and lateral resolutions have been demonstrated to be better than 20 microm. Detailed characterizations of the optical and acoustical properties of the etalon, as well as photoacoustic imaging results, suggest that thin polymer etalon arrays can be used as ultrasound detectors for 3-D high-resolution photoacoustic imaging applications.
authors.affiliation: University of Michigan, Department of Electrical Engineering and Computer Science, 1107 Carl A. Gerstacker Building, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109, USA. yang.hou.goblue@gmail.com
authors.forename: Yang
authors.initials: Y
authors.lastname: Hou
authors.forename: Sheng-Wen
authors.initials: SW
authors.lastname: Huang
authors.forename: Shai
authors.initials: S
authors.lastname: Ashkenazi
authors.forename: Russell
authors.initials: R
authors.lastname: Witte
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
mesh_terms: D017076:Computer-Aided Design; D054459:Elasticity Imaging Techniques / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers