How to increase S/N ratio by 10:1 in FIR transmission spectroscopy of high extinction index materials

Abstract

To obtain transmission spectra of materials with a high index of extinction is very difficult in the far IR for metals, superconductors, some ferroelectrics, etc. because films as thin as 300 Å are often transmitting less than 1%. It is shown that sticking the film onto a transparent plate and looking at the interference fringes can multiply transmission by a factor of 10 or more.