In this document, we describe twin-rainbow metrology, a non-invasive optical technique for measurement of the thicknesses of thin solid and liquid films to sub-micron accuracy. TRM allows measurement of coating thicknesses in two separate ways: first, directly, by a measurement of the difference between two scattering angles; ; and second, by the analysis of a moire pattern found in the superposition of two sets of interference fringes. In this paper we will examine the conditions under which twin-rainbow metrology can be used, the accuracy of measurements made by it, and its potential applications.
展开▼
