Laser diffraction is one of the most widely used methods for particle size analysis of micron and submicron size powders and dispersions. It is quick and easy and provides very consistent, repeatable information. Since these instruments use scattered light intensity to determine particle size, knowledge of the optical properties, specifically the complex refractive index of the material being a...

a negative index of refraction over a band of microwave frequencies1. This demonstration of a previously unexploited electromagnetic (EM) property proved the importance of engineered materials and has resulted in an extraordinary amount of continued development by scientists working in optics, electromagnetism, physics, engineering, and materials science. Experimental results revealing new phen...

Ultrasonic computed tomography (UCT) is one of the methods capable of tissue characterization. It is expected to provide not only a quantitative image but also diagnostic information. As in X-ray CT, UCT requires a projection data to reconstruct a cross-sectional image. In UCT such projection data are derived from the received broadband ultrasonic signal. In this paper, two methods for deriving...

The central focal masking ("dispersion staining") technique is convenient and effective for determining the refractive index of a microfragment by the immersion method and for distinguishing between minerals in an immersion mount. For most microscopes the only modification needed is the installation of a small opaque dot at or near the focal point of the medium power objective. White light illu...

Dispersion, as the characteristic variation of refractive index with wavelength, is more pronounced, where the wavelength is approaching to the absorption band. In ultra-optical glasses, the nonlinear refractive index, concerning to the light intensity dependent phenomenon, becomes considerable. Here, two ultra-optical property glass systems; TiO2-Bi2O3-PbO (TBP...

Specially designed metal-dielectric composites can have a negative refractive index in the optical range. Specifically, it is shown that arrays of single and paired nanorods can provide such negative refraction. For pairs of metal rods, a negative refractive index has been observed at 1.5 μm. The inverted structure of paired voids in metal films may also exhibit a negative refractive index. A s...