Woollam Variable Angle Spectroscopic Ellipsometer

The Variable Angle Spectroscopic Ellipsometer (VASE) is primarily used to measure the thickness and optical properties (index of refraction and extinction coefficient) of thin film materials. Measurements are made by analyzing polarized light reflected from the sample surface, and fitting the measured data to a model. Typically dielectric and semiconductor films are measured, though very thin metal films can also be analyzed.