Accession Number : ADA134138

Title :   Profile of Laser-Produced Acoustic Pulse in a Liquid.

Descriptive Note : Technical rept.,


Personal Author(s) : Tam,A C ; Sullivan,B

PDF Url : ADA134138

Report Date : 12 Oct 1983

Pagination or Media Count : 26

Abstract : Recently, Lai and Young have independently calculated the profile of a thermo-elastically generated opto-acoustic pulse due to the passage of an excitation laser pulse of certain spatial and temporal intensity distributions in a weakly absorbing medium. The authors of this document have found that Lai's Young's results are essentially equivalent for Gaussian intensity distribution of the excitation laser. The authors report the first experimental verification of such theoretical opto-acoustic profiles excited by laser pulses of various pulse widths tau FWHM (8 nsec and 1.3 microsecs) focussed to different beam waists w sub o. Observation of the profile is performed with a probe beam deflection technique instead of using conventional acoustic transducers which have limited risetimes and nonflat frequency response. The author's are in reasonable agreement with theory, and clearly indicate that sharp opto-acoustic pulses can be generated by laser pulses of short tau FWHM and small w sub o.

Descriptors :   *Acoustic waves, *Acoustooptics, *Wave propagation, *Laser beams, Pulses, Propagation, Thermal expansion, Profiles, Probes, Deflection, Excitation, Lasers, Intensity, Distribution, Normal density functions, Numerical analysis, Liquids

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE