Biomedical subjects

Andrea Guarino

Publications and source records attributed to Andrea Guarino.

2 recordsLinked to original sources

PubMed2005

Nondestructive method for the characterization of ion-implanted waveguides.

A new method, called barrier coupling, for coupling light into ion-implanted waveguides is presented in analogy to prism coupling. Light is coupled by frustrated total reflection at the barrier region of decreased refractive index by proper variation of the incident angle. Effective indices of guided modes are determined by the minima of the non-incoupled reflected light. The method is used for the determination of the effective indices of an ion-implanted waveguide in KNbO3. It is simpler than most other techniques, more accurate, and nondestructive.

Journal Article↗

PubMed2002

Soret effect in interacting micellar solutions.

We show that electrostatic effects have a dramatic influence on thermal diffusion of charged micelles. In the dilute regime, the Soret coefficient strongly decreases with the solution ionic strength, and scales as the square of the Debye-Hückel length. Yet, collective effects yield a reversed scenario even at fairly low surfactant concentration. We find that single-particle behavior can be explained using an interfacial tension mechanism proposed by Ruckenstein, which also fairly accounts for collective effects and opens the way to a general picture of thermal diffusion in disperse systems.

Journal Article↗