title: High frequency optoacoustic arrays using etalon detection.
abstract: Two-dimensional phased arrays for high frequency (>30 MHz) ultrasonic imaging are difficult to construct using conventional piezoelectric technology. A promising alternative involves optical detection of ultrasound, where the array element size is defined by the focal spot of a laser beam. Element size and spacing on the order of a few microns are easily achieved, suitable for imaging at frequencies exceeding 100 MHz. We have previously shown images made from a receive-only, two-dimensional optoacoustic array operating at 10 to 50 MHz. The main drawback of optical detection has been poor sensitivity when compared with piezoelectric detection. In this paper, we explore a different form of optical detection demonstrating improved sensitivity and offering a potentially simple method for constructing two-dimensional arrays. Results from a simple experiment using an etalon sensor confirm that the sensitivity of etalon detection is comparable with piezoelectric detection. This paper concludes with a proposal for a high frequency optoacoustic array system using an etalon.
authors.affiliation: General Electric Company, Milwaukee, WI 53201-0414, USA. james.hamilton@med.ge.com
authors.forename: J D
authors.initials: JD
authors.lastname: Hamilton
authors.forename: T
authors.initials: T
authors.lastname: Buma
authors.forename: M
authors.initials: M
authors.lastname: Spisar
authors.forename: M
authors.initials: M
authors.lastname: O'Donnell