Patent ID: 9632005
Date: 2017-04-25
CPC Classifications: G01B,G01M,G02B

Claim:
1. A Fizeau interferometer comprising: a light source configured to generate light; a diffractive lens configured to receive the light from the light source and to generate first diffracted light; a mirror, spaced apart from the diffractive lens, the mirror configured to reflect the first diffracted light toward the diffractive lens, the diffractive lens configured to direct the first diffracted light reflected by the mirror to an image surface of the diffractive lens; and a detector positioned proximate the image surface of the diffractive lens, wherein the diffractive lens is configured to reflect a portion of light directed from the image surface back to the image surface as second diffracted light, the second diffracted light having a different diffraction order than the first diffracted light, and the detector is configured to detect interference between the first diffracted light and the second diffracted light.