POTENTIALITY OF THE PHOTOTHERMAL SURFACE-DISPLACEMENT TECHNIQUE FOR PRECISELY PERFORMED ABSORPTION MEASUREMENT OF OPTICAL COATINGS

The influence of sample properties on the measured signal has to be in vestigated, so that measurements of the optical absorption in thin-fil m coatings by means of the photothermal surface-displacement technique may be precisely performed. Carrying out simultaneously absorption me asurements on metal coatings at lambda = 10.6 mum by using laser calor imetry as well as the surface-displacement technique, the aforemention ed influence and the validity of assumptions of the theoretical model, respectively, can be proven. It can be demonstrated that, in contrast to the model, thermophysical coating properties contribute to the pro bed surface displacement.