Apparatus and method for a high-gain double-clad amplifier
US7526167B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 23, 2006 |
| Grant date | Apr 28, 2009 |
| Priority date | — |
| Expiry date | Jun 23, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/094007
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical apparatus design and method for suppressing cladding-mode gain in fiber- and other waveguide-amplification devices. In some embodiments, a signal-wavelength-absorbing core or region is included within the pump cladding or the pump waveguide, in order to absorb signal-wavelength radiation that occurs in the regions where only pump-wavelength radiation is wanted. This absorbing region prevents cladding-mode gain, thus preserving more pump-wavelength excitation for amplifying the desired signal radiation. In other embodiments, the refractive-index profile of the fiber or other waveguide is adjusted to reduce the numeric aperture and thus reduce the angle of light that will remain in the cladding. Since amplified spontaneous emission (ASE) occurs at all angles, a lower-NA fiber will leak a higher proportion of ASE (since a relatively lower portion of the ASE radiation is within the smaller angle that is retained within a low-NA fiber), while pump light, which was introduced into the fiber within the lower-NA angle will remain in the cladding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.