title: A scanning acoustic microscope based on picosecond ultrasonics.
abstract: We report on the development of a new type of scanning acoustic microscope. We use a femtosecond light pulse to generate a short sound pulse, and then focus this sound onto the sample by means of a specially designed and microfabricated acoustic lens of radius a few microns. The sound travels to the sample through a thin layer of water. The sound reflected from the sample is collected by the lens and then passes through a monolithically integrated optical resonant cavity. The induced change in the properties of this cavity are measured using a time-delayed probe light pulse. We describe some of the challenges involved in the construction and operation of this high-precision metrology apparatus and present some preliminary results.
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912, United States.
authors.forename: S
authors.initials: S
authors.lastname: Che
authors.affiliation: School of Engineering, Brown University, Providence, RI 02912, United States.
authors.forename: P R
authors.initials: PR
authors.lastname: Guduru
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912, United States; School of Engineering, Brown University, Providence, RI 02912, United States.
authors.forename: A V
authors.initials: AV
authors.lastname: Nurmikko
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912, United States; School of Engineering, Brown University, Providence, RI 02912, United States. Electronic address: Humphrey_Maris@brown.edu.
authors.forename: H J
authors.initials: HJ
authors.lastname: Maris
keywords: Acoustic lens; Acoustic microscope