N x M optical wavelength routing switch
US6097518A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1998 |
| Grant date | Aug 1, 2000 |
| Priority date | — |
| Expiry date | Mar 10, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2011/0035
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A switchable wavelength router switches wavelength division multiplexed (WDM) optical signals between N input ports and M output ports. Each WDM signal is spatially decomposed into N pairs of orthogonally polarized beams by a polarization-dependent routing element, such as a birefringent element. A polarization rotator array rotates the polarization of each beam pair so that both beams in each pair have the same polarization. A wavelength filter then demultiplexes each beam pair to create N sets of four beams, such that the first beam in each pair decomposes into third and fourth orthogonally-polarized beams, and the second beam in each pair decomposes into fifth and sixth orthogonally-polarized beams. The third and fifth beams carry a first spectral band at a first polarization, and the fourth and sixth beams carry a second complementary spectral band at an orthogonal polarization. A second polarization-dependent routing element spatially routes the four beams in each of the N sets based on their polarizations, and also spatially combines selected beam pairs from different sets to produce M pairs of beams. A second polarization rotator array restores each beam pair to orthogonal p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.