Reflection acoustic microscopy

Atalar, A., "An Angular Spectrum Approach to Contrast in Reflection Acoustic Microscopy, /. Appl. Phys., Vol. 49, 1978, pp. 5130-5139. 

Kojima, S. (1987). Interference fringes in reflection acoustic microscopy. Jap. J. Appl. Phys. 26 (Suppl. 26-1), 233-5. [255]... 

Lee, C. C., Tsai, C. S., and Cheng, X. (1985). Complete characterization of thin- and thick-film materials using wideband reflection acoustic microscopy. IEEE Trans. SU-32, 248-58. [207]... 

Wickramasinghe, H. K. (1978). Contrast in reflection acoustic microscopy. Electron. Lett. 14, 305-6. [108]... 

Fig. 2.1. A lens for high-resolution acoustic microscopy in reflection. The central transparent part is a single crystal of sapphire, with its c-axis accurately parallel to the axis of the cylinder. The sandwich structure at the top is the transducer, with the yellow representing an epitaxially grown layer of zinc oxide between two gold electrodes. The pink shaded areas within the sapphire represent the plane-wavefronts of an acoustic pulse they are refracted at the lens cavity so that they become spherical in the coupling fluid. A lens for use at 2 GHz would have a cavity of radius 40f[Pg.8]

The resolution of reflection instruments such as the one described here may be tested by imaging a specimen with a fine grating ruled on it. Figure 2.6 shows an image of a grating with a period of 0.8 pm at 2.0 GHz. At lower frequencies the pattern was not resolved at all (cf. Hoppe and Bereiter-Hahn 1985), but at 1.7 GHz, and above it can be seen quite well. The enormous amount of creative research that has gone into making acoustic microscopy with this kind of resolution routinely possible should not be underestimated (Jipson and Quate 1978). Chapter 3 considers the factors that determine and limit that resolution. 

Matthaei, E., Vetters, H., and Mayr, P. (1990). Reflective scanning acoustic microscopy for imaging subsurface structures in solid state materials. In Advanced materials and processes (ed. H. E. Exner and V. Schumacher), pp. 1415-20. DGM Informationsge-sellschaft mbH, Oberursel. [200, 219]... 

As a consequence, researchers from different disciplines of the life sciences ask for efficient and sensitive techniques to characterize protein binding to and release from natural and artificial membranes. Native biological membranes are often substituted by artificial lipid bilayers bearing only a limifed number of components and rendering the experiment more simple, which permits the extraction of real quantitative information from binding experiments. Adsorption and desorption are characterized by rate constants that reflect the interaction potential between the protein and the membrane interface. Rate constants of adsorption and desorption can be quantified by means of sensitive optical techniques such as surface plasmon resonance spectroscopy (SPR), ellipsometry (ELL), reflection interference spectroscopy (RIfS), and total internal reflection fluorescence microscopy (TIRE), as well as acoustic/mechanical devices such as the quartz crystal microbalance (QCM)... 

SEAM Scanning Easer Acoustic Microscopy Bulk, film Acoustic wave produced by laser 1 MHz-1 GHz Reflected acoustic wave [jm-cm 0.1-20 mm Defect structure thickness measurement 60... 

Crystar. Tradename. A form of RECRYSTALLISED SILICON CARBIDE (q.v.) in which SiC and electronic grade Si react at over 2300 °C, and the grains recrystallize to form a continuous network of SiC. Crystar is used to produce thermal shock resistant kiln furniture as well as tubes and other refractory shapes. (Norton Co, USA). C-Scan Acoustic Microscopy, C SAM. Focussed transducers from 10 to 100 MHz are coupled to the test piece in a water-immersion tank so that the test-piece is located at the desired depth below the test-piece surface. (The reflections from that surface itself are cut out electronically). Scanning the transducer over the surface produces an image of internal flaws at that depth in the specimen. 

We used 900-MHz scanning acoustic microscopy to assess the acoustic impedance with a micrometer resolution. Acoustic microscopy measures the amphtude of a high frequency ultrasonic pulse reflected from the surface of a materM. The microscope is calibrated with a set of materials which have... 

A wide-field pulse scanning acoustic microscope (WFPAM) was used in the reflection mode at the driving frequencies of / = 25 — 50 — 100 MHz to measure the local values of ultrasonic velocities and elastic moduli (the microacoustic technique) and to visualize the bulk microstructure of a specimen (scanning acoustic microscopy). The method makes it possible to measure the elastic characteristics of small specimens and inclusions [26,27]. 

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