High Resolution Ultrasonic Scanning System

High-resolution scanning SQUID microscope

We have combined a novel low temperature positioning mechanism with a single-chip miniature superconducting quantum interference device ~SQUID! magnetometer to form an extremely sensitive new magnetic microscope, with a demonstrated spatial resolution of ;10 mm. The design and operation of this scanning SQUID microscope will be described. The absolute calibration of this instrument with an idea...

Resolution of scanning ultrasonic imaging systems with arbitrary transducer excitation

2014 An analytical formulation is presented which predicts the imaging performance of broadband ultrasonic imaging systems. The effect of frequency dependent attenuation on image resolution is analysed. Examples of the case of a narrow RF pulse and a wideband FM chirp pulse excitation are presented. It is shown that as far as the imaging resolution is concerned it is possible to make a very goo...

Polarimetric high-resolution confocal scanning laser ophthalmoscope

A polarimetric high-resolution confocal scanning laser ophthalmoscope has been developed. The system incorporates a fixed linear polarizer in the illumination path and a rotatory quarter-wave plate and another fixed linear polarizer in the registration path. Retinal areas that are smaller than those provided by commercial instruments can be imaged. Series of four fundus images for independent p...

Scanning transmission electron microscopy at high resolution.

We have shown that a scanning transmission electron microscope with a high brightness field emission source is capable of obtaining better than 3 A resolution using 30 to 40 keV electrons. Elastic dark field images of single atoms of uranium and mercury are shown which demonstrate this fact as determined by a modified Rayleigh criterion. Point-to-point micrograph resolution between 2.5 and 3.0 ...

11. High-resolution Scanning Electron Microscopy