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:
Nov. 13, 2012
Filed:
Dec. 21, 2007
Paolo Martelli, Milan, IT;
Mario Martinelli, Milan, IT;
Aldo Righetti, Milan, IT;
Google Inc., Mountain View, CA (US);
Abstract
A method of stabilizing the state of polarization of an optical radiation comprises: 1) applying sequentially to the optical radiation a first and a second controllable phase retardation; 2) detecting an optical power of at least a first polarized portion of the optical radiation obtained after step 1; 3) applying sequentially to the optical radiation obtained after step 1 a third and a fourth controllable phase retardation; 4) detecting an optical power of a further polarized portion of the optical radiation obtained after step 3; 5) controlling, responsive to the optical power of said first polarized portion, the second controllable phase retardation so as to maintain the polarization state of the optical radiation obtained after step 1 at a defined great circle r on a Poincare sphere; 6) in case the second controllable phase retardation reaches a first limit value, commuting the first controllable phase retardation between first and second values; 7) controlling, responsive to the optical power of said further polarized portion, the fourth controllable phase retardation so as to maintain the polarization state of the optical radiation obtained after step 3 at a defined state of polarization; 8) in case the fourth controllable phase retardation reaches a second limit value, commuting the third controllable phase retardation between third and fourth values, keeping constant the first controllable phase retardation while the third controllable phase retardation is commuting between said third and fourth values. A polarization stabilizing device based on the method above is also disclosed.