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:
Sep. 01, 2026
Filed:
Aug. 24, 2021
Applicant:
Fujikura Ltd., Tokyo, JP;
Inventor:
Rintaro Kitahara, Sakura, JP;
Assignee:
Fujikura Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01S 3/067 (2006.01); H01S 3/16 (2006.01);
U.S. Cl.
CPC ...
H01S 3/06716 (2013.01); H01S 3/0675 (2013.01); H01S 3/1618 (2013.01); H01S 3/06733 (2013.01); H01S 2301/03 (2013.01);
Abstract
A rare-earth doped fiber includes: a core having a radius R and having a doped region to which a rare-earth element has been doped, the doped region ranging from a center of the core to a radius R; and a cladding surrounding a circumference of the core and having a refractive index lower than a refractive index of the core. A normalized frequency V at an operating wavelength is greater than or equal to 2.4 and less than or equal to 4.5. The radius Ris in a range of 0<R<