On the use of laser-ultrasonics technique to excite selectively cylinder acoustic resonances.
Acoustic propagation in the transverse plane of a cylinder is considered in this paper. The acoustic source is a line along the axis z of the cylinder coordinates, obtained by focusing the beam of a pulsed laser on the surface of the cylinder. Point detection is performed with a laser interferometer. By adequately combining elementary signals measured for a large number of relative source-receiver positions, a signal is synthesized containing the basic acoustic resonances of the cylinder. Various elementary signal combinations allow us to select the observed acoustic modes related to Whispering Gallery modes and to Rayleigh surface waves. The changes in the signal spectrum are discussed. These acoustic modes are experimentally selected and observed at ultrasonic frequencies for the first time.
Audoin
B
B
Laboratoire de Mécanique Physique, UMR CNRS 5469, Université Bordeaux 1, 351 Cours de la Libération, 33405-Talence, France. b.audoin@lmp.u-bordeaux1.fr <b.audoin@lmp.u-bordeaux1.fr>
Pan
Y
Y
Rossignol
C
C
Chigarev
N
N