Abstract: An apparatus for providing a light beam with spatially varying polarization. The apparatus comprises: two circumferentially curved reflectors positioned substantially opposite each other, a polarizer positioned in an optical path between the two reflectors, for polarizing light reflected from one reflector before it reaches the other. A non-polarized light beam incident along a given axis on one of the reflectors is radially reflected off that reflector, acquires predetermined polarization from the polarizer and is then reflected off the second reflector to a light beam of spatially varying polarization.

Abstract: A device for measuring simultaneously the phase at each point of an image formed by light reflected from a sample in which the phase has been modified by plasma resonance in a thin conducting layer, the device comprising a thick transparent substrate (10) on which a thin layer of conducting material is deposited (13); a light source (1); an interferometer; an imaging means (9); and a processing means.

Abstract: A method and apparatus for determining the topography of a thin film having a front surface and a back surface. The method comprises: irradiating the film with an incident coherent or partially coherent beam so as to get two reflected beams, the first reflected from the front surface, and the second from the back surface; and using a third reference beam originating from the incident beam, and substantially parallel to the two reflected beams, wherein the third reference beam acquires a controlled phase shift. The three said beams are used to create an interferometric image of the film, whereby the interference of the three beams allows acquisition of information on the topography of the film that cannot be acquired using the two reflected beams alone.