Patent ID: 7869058

Claim:
A system for evaluation of optical quality of an optical device, said system comprising: a light source configured to provide light to the optical device; a computer; a camera, that receives and displays interference fringes; and an interferometric lens apparatus comprising a first lens, a point diffraction interferometer (PDI) and a second lens, wherein said interferometric lens apparatus is configured to be removably mounted to the optical device, and is configured to generate interference fringes, wherein said PDI comprises a material coated onto a surface of said PDI, wherein said material coated onto the surface of said PDI is a small circular region formed as an opaque spot coating which forms a partial obstruction to light provided to the optical device, causing light provided from the optical device to surround said partial obstruction, which causes a reference wave to form, by diffraction at an edge of said opaque spot coating, wherein the reference wave and light surrounding said partial obstruction are transmitted to the camera, wherein said opaque spot coating is a partially transmitting opaque coating, wherein said first lens, said PDI, and said second lens are formed as a single integrated unit that is removably mounted onto the optical device, wherein the single integrated unit that is removably mounted includes a plurality of spacers spacing said first lens, said PDI, and said second lens at a predetermined distance, wherein said partial obstruction and the plurality of spacers are composed of a low thermal expansion material, and wherein said low thermal expansion material includes one or more of aluminum, steel and glass.