OPTOACOUSTIC SPECTROMETRY OF SURFACES - DIELECTRIC COATINGS FOR LASER MIRRORS

A double-beam optoacoustic spectrometer has been employed to obtain the transmission, reflectance, and absorption spectra of a number of dielectric-coated glasses used for laser mirror applications. The complementary nature of these spectra is demonstrated and, by simply reversing the sample within the optoacoustic cell, the absorption spectra of the surface coating and the substrate may be determined independently.