Patent ID: 7738117
Filing Date: 2010-06-15
Classification: G01B

Abstract:
1. An interferometer system comprising: an optical delay apparatus including at least one beam splitter and at least one reflector for providing first and second optical paths having first and second optical path lengths, respectively, for a beam of light traversing the optical delay apparatus, wherein a distance between the at least one beam splitter and the at least one reflector is adjustable to adjust an optical path length difference between the first and second optical path lengths; a light source for generating light of a coherence length; and a Fizeau interferometer including an interferometer optics and a first Fizeau reference surface for directing measuring light towards an optical surface to be tested and disposed at a distance greater than half of the coherence length from the first Fizeau reference surface; a position sensitive detector including a light detecting surface; wherein the light source, the optical delay apparatus, the Fizeau interferometer and the detector are arranged such that measuring light generated by the light source may traverse the optical delay apparatus and the Fizeau interferometer to be incident on the detector, such that a portion of the measuring light traversing the Fizeau interferometer is reflected from the first Fizeau reference surface, such that a portion of the measuring light traversing the Fizeau interferometer is reflected from the optical surface to be tested, and such that at least portions of the Fizeau surface and of the optical surface to be tested are imaged through the interferometer optics onto at least a portion of the light detecting surface of the detector; wherein the interferometer system further comprises an aberration reducing transfer optics to supply the measuring light having traversed the optical delay apparatus to the Fizeau interferometer, wherein the aberration reducing transfer optics comprises an optical fiber.