Dual horizontally oriented triangle shaped optical retarder element for use in spectroscopic ellipsometer and polarimeter systems

摘要

A retarder system, for entering retardation between orthogonal components of an electromagnetic beam of radiation, having first and second triangular shaped elements arranged so that the first triangular shaped element, as viewed in side elevation, presents with first and second sides which project to the left and right and downward from an upper point, with a third side which is oriented essentially horizontally and is continuous with, and present below the first and second sides; and so that the second triangular shaped element, as viewed in side elevation, presents with first and second sides which project to the left and right and upward from a lower point, with a third side which is oriented essentially horizontally and is continuous with, and present above the first and second sides. During use in a spectroscopic ellipsometer/polarimeter system, a beam of electromagnetic radiation exits in a propagation direction which is essentially undeviated and undisplaced from the direction of an incident beam of electromagnetic radiation, even when the retarder system is caused to rotate about the locus of the beam of electromagnetic radiation.