Materials Evaluation by Acoustic Microscope.

All-Optical Scanning Acoustic Microscope

In this thesis a new instrument, the all-optical scanning acoustic microscope (O-SAM) is presented, it is a non contact scanning acoustic microscope (SAM) which uses lasers to both generate and detect surface acoustics waves (SAWs) The non contact nature of the O-SAM overcomes some difficulties associated with conventional SAMs because of the couplant and surface contact involved. This O-SAM al...

Acoustic materials

Acoustic Transduction Materials and Devices

The applications are to Cymbal and Tonpilz transducer arrays for 3 50 kHz sonars, thin/thick film transducers for 10 100 MHz medical acoustic devices, underwater intensity sensors for lowfrequency surveillance, and flexural amplification mechanisms of the solid state strain for air acoustic transduction. Modeling and computer simulations of domain motions and structural vibrations and supportin...

Acoustic Microscopy for Materials Characterization

An acoustic microscope with mechanical scanning and piezoelectric film transducers for the input and output has been developed for the microscopic examination of materials.1 In the reflection mode it is possible to work with an acoustic wavelength of 0.5 micrometers and a resolution that compares to that of the optical microscope. The elastic images of material surfaces as recorded with this in...

Acoustic neuromas: evaluation by magnetic resonance imaging.

Proton magnetic resonance imaging (MRI) examinations were performed in six patients with seven acoustic neuromas, and the results were compared with conventional tomography of the internal auditory canals, contrast-enhanced computed tomography (CT), and air CT cisternography. All tumors were identified with MRI. The three largest tumors (greater than 1 cm diameter) looked similar to the tumors ...