Polarization Effects In Interferometric Testing With F/1 Diffractive Transmission Sphere

Diffractive optics are promising for use in interferometry as a Transmission Sphere (TS) due to the fact that it is simpler and cheaper, since it consists of one component. However, in the manufacture and use of Diffractive TS (DTS) with an aperture up to f/1, many problems arise that are not specific for classical TS. One of these problems is the effects of polarization, which can affect the interferogram. These negative effects can occur when diffractive TS has a period close to the interferometer wavelength. This work is devoted to computer simulation of such effects and development of technique for their partial compensation. To avoid the harmful effects of laser beam depolarization and to decrease the two-pass transmittance of a typical DTS at its margins, we decompose the local linear polarization into the radial and azimuthal components and evaluate separately the forward and backward transmittance of each polarization component for the case with a spatially variable prescribed local duty cycle.