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. 31, 2005
Filed:
Feb. 24, 2003
Applicants:
Hikaru Hoshi, Tochigi, JP;
Yasushi Kaneda, Saitama, JP;
Inventors:
Hikaru Hoshi, Tochigi, JP;
Yasushi Kaneda, Saitama, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B005/18 ; G02B027/44 ; G01J003/18 ; H04J014/02 ;
U.S. Cl.
CPC ...
Abstract
A beam splitting element having a diffraction grating is designed by careful selection of device parameters such as grating period, duty cycle, depth and refractive index. In particular, the parameters are selected in such a way that the product of refractive index, depth and duty cycle is equal to or bigger than a predetermined value. The diffraction grating device designed by these rules exhibits a high diffraction efficiency and small polarization dependence.