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:
Jan. 15, 1980
Filed:
Sep. 11, 1978
Robert B Russell, Chestnut Hill, MA (US);
Other;
Abstract
An interferometer device and method for detecting variations in the effective path length of light on opposite sides of an enclosed ring-like optical path. Laser light is split and passed in opposite directions around an area in one or more planes to a point where the beams come together at which point they are directed, in coincidence, into one or more photodetectors. A variable light delay means is located in each light path and each delay means is operated repetitively to vary the delay by a selected amount and at a selected rate to produce repeating bursts of selected beat frequencies at said photodetector. After heterodyning the beat frequencies down, the differences therebetween are repetitively measured by a frequency counter to a high degree of accuracy by long term averaging. Slow rates of rotation of the apparatus about an axis normal to the plane of the enclosed path are detected independently of noise in the system and variations in the frequency of the laser.