ABSTRACT
The most common and versatile among them is interferometry, which has unsurpassed accuracy and allows one to directly obtain a pattern of wave front deviations at very large apertures. The Zernike phase contrast method is a powerful tool for transforming the spatial phase information of an optical beam into a spatial intensity distribution without absorbing light. The basic principle is to split a light beam into its Fourier components using a lens and a filter. The introduced phase shift creates an intensity distribution in accordance with the phase information carried by the higher spatial frequencies. Aberrational representations are more efficient in terms of data volumes and also allow one to make use of the wave front features that are important for solving specific problems. Active employment of Zernike polynomials for representation of wave aberrations stimulates the development of new sensors, including for direct measurements of expansion coefficients by the Zernike basis.
