Fiber amplifiers with depressed cladding and their uses in Er-doped fiber amplifiers for the S-band
US6909538B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2002 |
| Grant date | Jun 21, 2005 |
| Priority date | — |
| Expiry date | Apr 12, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A fiber amplifier in a depressed cladding or W-profile fiber. The fiber has a core doped with the active material and defined by a core cross-section and a refractive index no. A depressed cladding of index n1 surrounds the core and a secondary cladding of index n2 surrounds the depressed cladding. The fiber amplifier is pumped to a level of high relative inversion, such that the active material exhibits positive gains in a short wavelength band and high gains in a long wavelength band. The core cross-section, the depressed cladding cross-section and the refractive indices no, n1, and n2 are selected to obtain a roll-off loss curve about a cutoff wavelength λc. The roll-off loss curve yields losses at least comparable to the high gains in the long wavelength band and losses substantially smaller than the positive gains in the short wavelength band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.