INTERFERENCE TECHNIQUE FOR DETERMINING THE OPTICAL HOMOGENEITY OF LARGE BLANKS MADE FROM QUARTZ GLASS

An interference technique has been developed for determining the optic al homogeneity of glass samples having ground surfaces and sizes that substantially exceed the Light field of the test apparatus. The techni que envisions the use of a quasi-Fizeau interferometer and involves ob taining and processing several interferograms with the computer comple x of the device. The same complex then uses a specially developed prog ram to combine the interferograms into a single interferogram characte rizing the optical homogeneity of the entire sample.