INSTRUMENT FOR MEASURING THE THICKNESS OF TRANSPARENT FILMS

We devised and tested a rapidly acting interferometer for measuring th e thickness of transparent films, Its operating principle is based on the dependence of the reflection factor of a laser beam by a film on t he angle of incidence. The angle of incidence is changed with the aid of a nonspherical optical system. One measurement takes less than 0.00 1 sec so that nonuniformities of the thickness of films can be measure d and the kinetics of the change of thickness of films can be investig ated. The diameter of a sounding point is less than 100 mu m.