Modelling and correction for polarization errors of a 600 mm aperture dynamic Fizeau interferometer

Abstract

The polarization errors of large aperture dynamic interferometers based on the polarization phase shifting method are mainly coming from the effects of imperfect polarized elements and birefringence of large elements. Using the Lissajous ellipse fitting algorithm to correct the influence of the polarized device can effectively eliminate single and double frequency print through errors. We develop a wave plate model for analyzing the birefringence effect, and on this basis, we establish the relationship between the calculated phase and the ideal phase distribution. Experiments are carried out on a 600mm aperture Fizeau interferometer and then compared with the result acquired through the wavelength tuning method. The difference between PV is only 0.002λ.

Short-coherence laser based on ASE-induced white noise modulation

“…4D Technology proposed a short-coherence orthogonal-polarized light source based on the microwave-modulated laser diode (LD) and Twyman-Green optical path, compensating the OPD between the reference and test lights to realize the short-coherence dynamic interferometry of the parallel plates and large-aperture convex spheres [6]. In our previous work, a 600-mm Fizeau dynamic interferometer and a surface defect detection device were established through the orthogonal-polarized short-coherence scheme based on the multi-longitudinal-mode LD [7,8]. Zhang et.…”