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:
Oct. 07, 2003
Filed:
Mar. 16, 2001
Hongdu Liu, Fremont, CA (US);
Daxin Liu, Mountain View, CA (US);
Shizhuo Yin, Fremont, CA (US);
Lee Lisheng Huang, Sunnyvale, CA (US);
Primanex Corporation, Fremont, CA (US);
Abstract
Randomly polarized light impinges upon a birefringent crystal, is split into orthogonal polarization components and emerges from the crystal separated by a walk-off distance. The light beams then impinge on polarization rotators that cause a rotation of the plane of polarization by +45° and −45°. The light then encounters a variable polarization rotator in which the plane of polarization is rotated through a angle that varies in response to an externally-applied control signal. The maximum operating range (0 to 100% attenuation) is achieved when the variable rotator is capable of rotations in the range ±45°. A second birefringent crystal functions as a beam displacer. The beams encounter two wave plates configured to produce rotation angles of 0° and 90° followed by a retroreflector. The reverse traverse of the attenuator causes the light to emerge at an output port attenuated in intensity.