New Polarization Interferometer for Fourier Analysis*

Abstract

A generator of fringes of variable frequency is described as consisting of only two Wollaston prisms W1 and W2 with attached polarizers P1 and P2. A properly oriented half-wave plate H1 is situated between W1 and W2. When the two Wollaston prisms are counterrotated by an equal angle ø about an axis joining the geometrical centers of their faces, fringes appear of variable frequency ƒ = 4(Ne-N0) tanα cosø, where α is the angle of the prisms, Ne and N0 are the principal indices. When the fringe pattern is projected by a demagnifying microscope lens, the contrast remains constant up to 280 lines/mm.