APPARATUS AND METHOD FOR MEASUREMENT OF FIELDS OF BACKSCATTERED AND FORWARD SCATTERED/REFLECTED BEAMS BY AN OBJECT IN INTERFEROMETRY

摘要

An interferometry system for making interferometric measurements of an object, the system including a source assembly that generates an input beam; a detector assembly that includes a detector element; and an interferometer that includes a source imaging system that images the input beam onto a spot on or in the object and an object imaging system that images the spot onto the detector element as an interference beam, the object imaging system combining light coming from the spot with a reference beam to produce the interference beam, wherein the source imaging system is characterized by a first aperture stop that defines a first aperture and includes a first phase shifter that introduces a first phase shift in light passing through a first region of the first aperture relative to light passing through a second regino of the first aperture, and wherein the object imaging system is characterized by a second aperture stop that defines a second aperture and includes a second phase shifter that introduces a second phase shift in light passing through a first region of the second aperture relative to light passing through a second region of the second aperture.