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. 16, 2007
Filed:
Dec. 15, 2006
Valentin P. Gapontsev, Worcester, MA (US);
Mikhail Vyatkin, Moscow, RU;
Vladimir Grigoriev, Moscow, RU;
Valentin P. Gapontsev, Worcester, MA (US);
Mikhail Vyatkin, Moscow, RU;
Vladimir Grigoriev, Moscow, RU;
IPG Photonics Corporation, Oxford, MA (US);
Abstract
A large mode area optical fiber includes a large diameter core (dup to 60 μm), and a first cladding (diameter d) wherein the difference between refractive index (n) in the core and the first cladding (n) is very small (Δn<0.002), thus providing a very low numerical aperture core (NAbetween 0.02 and 0.06). The preferred ratio of d/d<2. The fiber further has a second cladding, preferably a layer of air holes, having a very low refractive index nas compared to the core and first cladding such that the first cladding has a relatively high numerical aperture (NA>0.4) (nis preferably less than 1.3). The small change in refractive index between the core and inner cladding combined with a large change in refractive index between the first cladding and second cladding provides a significantly improved single mode holding waveguide.