CHARACTERIZATION OF OPTICAL COATINGS BY PHOTOTHERMAL DEFLECTION

An overview of photothermal deflection principles and applications is given. The modeling of temperature distribution and the calculation of deflection that is due to both the refractive-index gradient and the thermal deformation of the sample are presented. Three configurations usually employed are compared, and their respective advantages are dis cussed in relation to their application. The calibration for absolute measurement of absorption is detailed, showing that calibration limits the accuracy of measurement. Some examples of specific information ob tained by photothermal mapping of absorption are given. (C) 1996 Optic al Society of America