title: High-sensitivity and wide-directivity ultrasound detection using high Q polymer microring resonators.
abstract: Small size ultrahigh Q polymer microrings working at near visible wavelength have been experimentally demonstrated as ultralow noise ultrasound detectors with wide directivity at high frequencies (>20 MHz). By combining a resist reflow and a low bias continuous etching and passivation process in mold fabrication, imprinted polymer microrings with drastically improved sidewall smoothness were obtained. An ultralow noise-equivalent pressure of 21.4 Pa over 1-75 MHz range has been achieved using a fabricated detector of 60 μm diameter. The device's wide acceptance angle with high sensitivity considerably benefits ultrasound-related imaging.
authors.affiliation: Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Ling
authors.forename: Sung-Liang
authors.initials: SL
authors.lastname: Chen
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Guo