Patent ID: 7081960
Filing Date: 2006-07-25
Classification: G01B

Abstract:
1. An interferometer, comprising: a light source; a beam splitter disposed in an optical path of light emitted by the light source and that splits the light emitted by the light source into a measurement beam and a reference beam; a fixed reflector disposed in an optical path of the reference beam and that reflects the reference beam; a moving mirror disposed in an optical path of the measurement beam and that includes at least two mutually orthogonal reflection planes; and an optical member disposed in the optical path of the measurement beam reflected by the moving mirror and that returns the measurement beam that has been reflected by the moving mirror back toward the moving mirror, wherein the measurement beam exits from the optical member at an exit point different from an incident point where the measurement beam entered the optical member, and when the incident point changes, the optical member causes the exit point to change by a same direction and amount.