1. A method for determining the correlation between layers in dielectric multilayers by nondestructive testing comprising the steps of: illuminating a dielectric multilayer with a beam of monochromatic light at a predetermined angle of incidence; measuring the angular distribution of scattered light from said multilayer stack; calculating the angular distribution of scattered light from said multilayer stack based on an assumed correlation relation between said multilayers; comparing said measured angular distribution to said calculated angular distribution; repeating said calculating and comparing steps for different assumed correlations between said multilayers until the closest fit between said calculated and measured angular distribution is identified; and redoing said illuminating, measuring, calculating, comparing, and repeating steps for a different angle of incidence of light on said multilayer stack a plurality of times, said plurality being determined by the number of different angles of incidence needed to evaluate a characteristic correlation relationship describing said multilayer stack for all angles of incidence.