[Amalgam: yesterday and today].

Recently some reports claim that mercury released from amalgam fillings cause adverse effect to the patient. Mercurial toxicity is a risk for dental personnel but it is completely preventable by using proper mercury hygiene. From the side of the patients, amount of mercury released from amalgam fillings is far to cause any adverse effect.

Scattering of sharply focused beams by arbitrarily shaped dielectric particles: an exact solution.

By expanding the incident focused beam field in terms of its plane wave spectrum and by using the technique we developed earlier to treat the problem of the scattering of plane waves by arbitrarily shaped dielectric obstacles, we have been successful in solving the problem of the scattering of sharply focused beams by arbitrarily shaped dielectric particles. It was found that the presence of the curvature of the incident wave front and the nonuniformity of the incident wave intensity affect greatly the scattering characteristics.

Scattering of a focused beam by moving particles.

The scattering of a focused laser beam by moving particles is studied. A solution is given for a spherical scatterer that is small compared to the wavelength. Several numerical examples are given.

Scattering of focused beams by tenuous particles.

This paper deals with the problem of the scattering of focused laser beams by tenuous particles using an iterative technique. The results are shown to be accurate provided that (a) the polarizability of the particle medium is small and (b) the phase shift of the central ray is less than 2. It was found that when the size of the incident beam waist is close to that of the scatterer, the scattered field deviates significantly from that for the incident plane wave case.