Photoacoustic Detection of Surface and Bulk Absorptions in a Standing Wave

Abstract

High power lasers require optical components with extremely low bulk and surface absorptions. A method which allows to determine separately these two contributions for a transmitting window is necessary if one wants to improve the material preparation and the polishing technique. When the surface is coated it is also important to be able to measure the intrinsic absorption of the coating material and the absorption occuring at the interfaces.