TEST OF MIRROR PAIR REFLECTIVITY COEFFICIENT EQUALITY AND HOMOGENEITY FOR INTERFEROMETRIC GRAVITATIONAL-WAVE DETECTORS

A bench for evaluating the homogeneity of coated optical surfaces specular reflection coefficient is presented. Comparison of the local reflectivity of a sample with a reference surface leads to the determination of the relative homogeneity delta R/($) over bar R of the sample. Various arangements that allow the study of high reflectivity mirrors or beamsplitter plates are described. When testing high reflectivity mirrors a sensitivity of 6 x 10(-5) on delta R/($) over bar R was achieved and a similar sensitivity was obtained when comparing two mirrors.