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. 27, 1997
Filed:
Oct. 06, 1995
Shoji Niki, Saitama, JP;
Eiji Kimura, Gyoda, JP;
Advantest Corporation, Tokyo, JP;
Abstract
A polarization state changing apparatus which can change the polarization state of an incident polarized light entering to an optical fiber to any direction and can output is provided. This polarization state changing apparatus, in an embodiment, comprises three polarization plane maintaining optical fibers 10, 20 and 300 which are serially connected at two polarization plane changing parts 30 and 30'. Those three polarization plane maintaining optical fibers are connected at the polarization plane changing parts 30 and 30'so that the optical axes X and Y of the adjacent optical fibers are mutually rotated at an angle of 45 degrees in terms of the fiber axis. Stress application parts for applying stress to each of the polarization plane maintaining optical fibers are provided. In a specific example, each optical fiber is wound around each piezoelectric element cylinder and predetermined stress is applied to each optical fiber by driving those piezoelectric element cylinders by power supplies each of which oscillating frequency and generated voltage are both variable. Also, a polarization degree measuring apparatus using the polarization state changing apparatus is provided to measure degree of polarization accurately and quickly.