Photoacoustic characterization of surface absorption

Photoacoustic spectrososcopy is used to characterize the surface absorption of polished fused silica substrates and thin films deposited on fused silica substrates. The extreme sensitivity of this technique allows measurement of surface absorptions of a few tenths of a part per million. Characterization of samples with surfaces finished using a variety of methods is reported. Key words: Photoacoustic ion beam absorption thin films. 1.