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. 29, 1998
Filed:
Nov. 15, 1996
Samuel N Fersht, Studio City, CA (US);
Donald A Frederick, Woodland Hills, CA (US);
Litton Systems, Inc., Woodland Hills, CA (US);
Abstract
The invention is a method and apparatus for determining the phase difference of light waves after propagating through each of one or more two-path pairs, a two-path pair being two optical transmission paths connecting a common entry point to a common exit point. Coherent light pulses of predetermined duration are fed into the entry point of each two-path pair in a group of two-path pairs at predetermined time intervals, the pulse duration being subdivided into a plurality of predetermined time segments. The light has a different frequency during each time segment. The light pulses at the exit points of the two-path pairs are delayed by predetermined time increments and then combined into a combination light signal. The combination light signal is converted into an electrical signal, the amplitude of the electrical signal as a function of time being proportional to the combination-light-signal power as a function of time. The phase difference for each two-path pair is determined from amplitude values of the electrical signal.