Filters to adjust DWDM transmissivity
US6404521B1 · kind B1 · utility
5Cited by
5References
24Claims
0Family size
Assignee
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Key dates
| Filing date | Oct 5, 2000 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Nov 18, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
System and method for wavelength discrimination using a DWDM (N+1)-stage fiber optic cascade tree structure with additional filtering to provide acceptable flat-top passband response, and to provide acceptable optical isolation when combined with a multilayer thin film filter. Each channel in a DWDM cascade tree structure has a conventional Mach-Zehnder interferometer (MZI) that provides wavelength discrimination. Each channel in at least one stage has an additional filter that is either (1) an inverted Fabry-Perot etalon (FPE) or (2) an inverted, non-symmetric MZI. The number of output channels may be 32, 64, 128 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.