Optical Bragg imaging of acoustic fields after reflection.

Bragg diffraction of x-rays occurs when the rays interact with a crystalline lattice at the appropriate angle. Bragg diffraction of visible light occurs when the light interacts at the Bragg angle with an ultrasonic field of the appropriate frequency. (The spacing between acoustic condensations and rarefactions acts like the planes in an atomic lattice.

Authors' Response to Strasberg's "Comment on 'Measurement of the frequency dependence of the ultrasonic parametric threshold amplitude for a fluid-filled cavity' " [J. Acoust. Soc. Am. 125, 1857 (2009)].

This letter is a response to Strasberg's recent paper, "Comment on 'Measurement of the frequency dependence of the ultrasonic parametric threshold amplitude for a fluid-filled cavity.'" The authors dispute the conclusions of Strasberg regarding the effect observed by Teklu et al. [J.

Observation of acoustical memory in LiNbO3.

A new physical effect is reported. In single crystals of lithium niobate (LiNbO3), we have observed an acoustical memory effect. An acoustical tone burst is stored inside the crystal and reemitted at a later time.