ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

3aPA13. Collinear ultrasonic four-wave mixing mediated by a suspension.

Christopher S. Kwiatkowski

Philip L. Marston

Dept. of Phys., Washington State Univ., Pullman, WA 99164-2814

In previous work, ultrasonic four-wave mixing mediated by a suspension was observed by oblique Bragg reflection of a high-frequency probe wave from a periodic grating [H. J. Simpson and P. L. Marston, 2244(A) (1991)]. The grating in the number density of suspended polymer microspheres was induced by the radiation pressure of a standing pump wave. In the present investigation, a different geometry is examined which has potential advantages for the investigation of this class of mediated interactions of sound with sound. The new geometry uses a high-frequency probe beam that is collinear with the axis of the pump standing wave. The Bragg signal for this geometry is amenable to analysis with transfer matrices. The interaction investigated has potential applications to the acoustical probing of suspensions. [Work supported by the Office of Naval Research.]