Wavelength monitoring optical fibers using detection in the near field
US6885792B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2002 |
| Grant date | Apr 26, 2005 |
| Priority date | — |
| Expiry date | Nov 9, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/124
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The specification describes a wavelength monitoring system for multiple wavelength communications systems, such as WDM systems, based on the recognition that the mechanism for spatially separating the individual wavelength bands can be achieved within the optical fiber itself. Individual wavelength bands are separated using a series of discrete gratings spaced longitudinally along the fiber core. The wavelength bands are extracted from the fiber core by converting the energy in the selected band from a core-guided mode to a radiation mode. By using a tilted grating, the light in the radiation mode is directed through the cladding and out of the fiber. Spatial resolution of the selected bands can be any desired physical length. An important implication of this is that detection can be made in the near field using inexpensive detecting apparatus. Near field is defined for convenience in this case as the optical field of the radiated energy without any optically modifying elements (collimating devices, diffraction elements, mirrors, etc.). This eliminates nearly all of the optics, and the attendant expense, in prior art monitoring systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.