The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 10, 1996
Filed:
Nov. 30, 1994
Thomas J Dunn, Mohegan Lake, NY (US);
Dharmesh G Panchal, Greenwich, CT (US);
Anvik Corporation, Hawthorne, NY (US);
Abstract
The absolute distance measuring interferometer (ADMI) is a multi-pass interferometer which is a resonant cavity consisting of two plane parallel mirrors whose length is referenced to a stabilized laser system. The resonant cavity can be used in order to measure very precisely (to within a fraction of a wavelength) the distance between a reference plane and an object. Due to its multi-pass nature, the length of the cavity can be measured much more accurately than for a conventional interferometer. The optical transmission bandwidth of the resonant cavity is inversely proportional to its length. A direct measure of the transmission bandwidth provides an extremely precise (to within a fraction of a wavelength) absolute measure of the length of the cavity. This eliminates the need for careful alignment during the motion of one of the mirrors of the multi-pass interferometer. In fact one can completely decouple the mirrors of the resonant interferometer and reassemble the resonant cavity at a different separation and measure the change in distance. This is extremely useful in situations where it is not possible to change distances while maintaining alignment of the cavity.