Abstract: The ellipsometer and method involve directing polarized light for interaction with an optical system under study at different angles of incidence from a single beam of light and detecting the light interacted with the optical system by reflection and/or transmission for each of a plurality of different angles of incidence. The simultaneous illumination of the optical system under study at a whole range of angles of incidence from a single beam of light and the collection a large multiplicity of data from the different angles detected can be accomplished rapidly and easily and with accuracy without scanning and with only one ellipsometer. A lens is used to focus the incoming light to provide the range of different angles of incidence. The range of angles is at least one or two degrees and preferably thirty degrees or more. A second lens refocuses the interacted light to a linear, multi-element detector array which extends in the plane of the incidence.