Fiber unbalanced Mach-Zehnder interferometers with flat-top spectral response for application in wavelength division multiplexers
US6263128A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 2, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jun 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/29319
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
According to the present invention, a multi-window wavelength division multiplexer (MWDM) is coupled to a correcting filter characterized by a shallow modulation depth and a channel separation smaller than the MWDM. A correcting filter is coupled to an input of the MWDM or to each of the two outputs of the MWDM. By changing the modulation depth and/or channel separation of the correcting filter(s), the spectral response of the filter can be adjusted to produce a more uniform gain (i.e., a "flat-top" spectral response) across wavelengths of passbands within the MWDM. In one embodiment, the correcting filter is an unbalanced Mach-Zehnder interferometer formed with two fused-fiber couplers having non-equal splitting ratios. In other embodiments, the correcting filter is a Fabry-Perot interferometer having a low end-face reflectivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.