Calculation and measurement of the absorption in multilayer films by means of photoacoustics

Abstract Using the photoacoustic gas cell microphone technique, absorption measurements were carried out in dielectric TiO 2 /SiO 2 multilayer stacks at λ = 515 nm. For an interpretation of the results the absorption signal was calculated. By an appropriate variation in the thickness of the high and low refracting components, a separate evaluation of the volume and interface absorption became possible. For the evaporated TiO 2 /SiO 2 multilayer system under investigation we found a predominance of interface absorption over volume absorption.