title: Nonlinear ultrasonic phased array imaging.
abstract: This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.
authors.affiliation: Faculty of Engineering, University of Bristol, Queen's Building, University Walk, Bristol BS8 1TR, United Kingdom.
authors.forename: J N
authors.initials: JN
authors.lastname: Potter
authors.affiliation: Faculty of Engineering, University of Bristol, Queen's Building, University Walk, Bristol BS8 1TR, United Kingdom.
authors.forename: A J
authors.initials: AJ
authors.lastname: Croxford
authors.affiliation: Faculty of Engineering, University of Bristol, Queen's Building, University Walk, Bristol BS8 1TR, United Kingdom.
authors.forename: P D
authors.initials: PD
authors.lastname: Wilcox
mesh_terms: D000162:Acoustics; D007091:Image Processing, Computer-Assisted; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D013816:Thermodynamics; D014465:Ultrasonics / Q000379:methods*