Study of optical material anisotropy using scanning millimeter wave beam

Millimeter wave bridge technique for non-destructive material homogeneity characterization is described. The idea of this technique is the local excitation of the millimeter waves in the testing material and the measurement of the transmitted (reflected) wave amplitude and phase in different places of it, i.e. the material plate is scanned by the beam of the millimeter waves. Same results of the homogeneity measurements for dielectric wafers according to dielectric constant anisotropy are presented. The measurement technique sensitivity is discussed.