title: Photoacoustic probes for nondestructive testing and biomedical applications.
abstract: Fiber-optic photoacoustic sources for nondestructive testing and biomedical applications are described. The photoacoustic sources consist of a pulsed laser, a fiber-optic cable, and a generation head. The generation head is a miniature hermetically sealed chamber, which can be embedded into solid structures or immersed in liquid media. The face of the chamber acts as a target for laser irradiation. Bulk ultrasonic waves generated inside of the target are transmitted into the medium. The proposed systems offer wide ultrasonic range (0.5-15 MHz), easy control over directivity of the ultrasonic beam, high efficiency of generation, and the ability to operate in a harsh environment. Sources with different radiation patterns with respect to the optical axis of the fiber, such as normal, sideways, as well as focused, have been devised. We present a proof-of-concept experiment using these sources in combination with fiber-optic ultrasonic receivers.
authors.affiliation: Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, Illinois 60208-3020, USA.
authors.forename: Pavel A
authors.initials: PA
authors.lastname: Fomitchov
authors.forename: Alexei K
authors.initials: AK
authors.lastname: Kromine
authors.forename: Sridhar
authors.initials: S
authors.lastname: Krishnaswamy
mesh_terms: D004867:Equipment Design; D004864:Equipment and Supplies; D005336:Fiber Optic Technology; D007834:Lasers; D055100:Optical Fibers; D012106:Research; D014463:Ultrasonography