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The on-axis intensity response of a confocal scanning optical microscope was measured for an objective of numerical aperture 0.9. The data compare favorably with theoretical calculations obtained by numerical integration of the standard theory, provided that lens aberrations are taken into account. The invariance of the shape of the central lobe to surface roughness and tilt is also demonstrated.

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Design criteria for acoustic microscope lenses are examined with respect to their intended application. Aside from buffer rod material and F-number, the factors influencing the lens design are the critical angle for surface wave excitation, lens illumination, and leak rate of the surface wave on the sample. It is found that the design criteria are different for surface and subsurface examination and that for different applications and materials, different lenses are required for optimum imaging performance. A formalism for evaluating the performance of an acoustic microscope by considering its response in the time domain, both theoretically and experimentally, is presented.

A zone-based technique for real-time color flow imaging is described. The technique utilizes a broad transmit beam which is equivalent to 20-50 focused transmit beams, such that the full field of view can be scanned using only 3-5 firings, times the flow sample count (FSC) required for color flow estimation. On receive, the channel domain RF data is pre-processed and accumulated in memory, and then transferred to a software-based image formation system, which performs dynamic receive focusing, clutter filtering, mean velocity estimation and scan conversion.Various methods of compensating for the lack of transmit focusing gain are discussed, including a larger FSC, over-sampling pulsed repetition frequencies, and coded excitation using FM chirp, Barker and Golay codes. Both 7.5 MHz linear array and 3 MHz curved array images obtained using a research platform show very good agreement with the predicted signal-to-noise-ratio (SNR) gain for a 5-chip Barker coded signal.