Loading patent…
AssigneeAvanex Corporation
InventorsIsabelle Riant, Carlos De Barros, Michel Jurczyszyn, Pierre Sansonetti
Estimating the term…
The invention relates to an optical fiber presenting a core, cladding, and a grating written by irradiation and coupling at least one light mode into the cladding so that it is dissipated therein. The invention proposes causing the mean index to vary progressively along the grating, at least at the ends of the grating. The progressive variation in mean index or in the amplitude of index modulation for writing the grating serves to limit insertion losses to the filter formed by the grating. Analogously, in a written-in grating, the invention provides the equivalent of progressively varying the core size of the fiber for interconnecting two optical fibers presenting different core diameters. The invention is applicable in particular to gain-equalizing filters in WDM transmission systems.
An optical filter having an insertion loss, the optical filter comprising an optical fiber that includes a grating having a first end, a second end, a mean index and an index modulation amplitude, wherein the mean index varies along the grating, diminishing progressively toward the first end such that the insertion loss is less than about 0.3 dB, and the index modulation amplitude varies in a non-monotonic fashion.
Dependencies are inferred from the claim text.