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. 03, 2011
Filed:
Dec. 11, 2006
Kenichi Nakamoto, Kawasaki, JP;
Kazuyuki Mori, Kawasaki, JP;
Kenichi Nakamoto, Kawasaki, JP;
Kazuyuki Mori, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A wavelength locker includes: a birefringent plate for separating light emitted from a light source into two beams of light which are approximately in parallel to each other; a first light receiving element for directly receiving one of the two beams of light separated by the birefringent plate; a λ/4 plate and an etalon filter through which other one of the two beams of light separated by the birefringent plate passes; and a second light receiving element for receiving the other one of the two beams of light which has passed through the etalon filter. The λ/4 plate has an optic axis tilted at 45 degrees with respect to a polarization direction of light incident on the λ/4 plate, changes a polarization direction of light, which has been reflected by the etalon filter and incident on the λ/4 plate, such that the reflected light does not return to the light source after passing through the birefringent plate, and emits the resultant light.