Rayleigh and Raman scattering measurements have been performed i n the 20-inch, Mach 6 wind tunnel at the NASA Langley Research Center . Rayleigh results show signal levels which are much higher than expected f o r molecular scattering in the tunnel, while densities deduced from s p o n t a n e o u s Raman scattering of molecular nitrogen are in good agreement with t h e expected nitrogen densi...

In a Scanning Acoustic Microscope (SAM) amplitude of focused acoustic beam reflected by a sample is utilized to produce acoustic images and to measure local elastic property for effective nondestructive characterization of materials. The most important acoustic rays involved in both imaging and quantitative measurements in an acoustic lens are shown in Fig.l. The extra contribution to the refle...

It is well known that harmonic bounded Gaussian beams undergo a transformation into two bounded beams upon reflection on a solid immersed in a liquid. The effect is known as the Schoch effect and can be found at the Rayleigh angle for thick plates and at the different Lamb angles for thin plates. Here, a study is made on the effect of pulsed Gaussian beams reflected on solids. It is found exper...