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:
May. 28, 2013
Filed:
Jul. 19, 2012
Charles G Askins, Upper Marlboro, MD (US);
Charles G Askins, Upper Marlboro, MD (US);
The United States of America, as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A method of measuring fiber twist in a multi-core optical fiber bearing an FBG with polarization dependent reflectivity. The state of polarization of the launched light is adjusted until the reflected FBG wavelength is maximal, indicating that light reaching the FBG is linearly polarized, and the polarization axis of the light reaching the FBG is aligned with the slow birefringent axis of the FBG; the SOP of launched light is now measured. Bending experienced by the fiber is measured conventionally, and birefringence produced by bending of the multi-core optical fiber is calculated. A candidate amount of twist between the launch location and the FBG is proposed, and the corresponding twist-induced birefringence is calculated. When calculations show that light with the launched SOP becomes linearly polarized and aligned with the FBG after traversing a fiber section with the calculated birefringences and proposed rotation, the amount of twist has been properly identified.