A new method for measuring refractive index and thickness of liquid and deposited solid thin films

Abstract We discuss theoretically a new method to determine the refractive index and the thickness of thin films using them as leaky waveguides. It is shown that the refractive index and the thickness can be determined easily by measuring the propagation constants of two leaky modes of this waveguide by means of synchronous angles. Experimentally we measured the refractive index of 1-bromonaphthalene and methylene iodide. This method is not restricted to special liquid and solid materials.