Optical switch, multiplexer, and demultiplexer
US5136671A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 21, 1991 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Aug 21, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/124
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An N.times.N integrated optical interconnection apparatus capable of switching, multiplexing, or demultiplexing a large number of input and output wavelength channels achieves low levels of crosstalk and insertion loss. Two substantially identical N.times.M star couplers are connected by an optical diffraction grating comprising M unequal length waveguides spaced from one another by predetermined amounts. Each coupler comprises a dielectric slab defining a free space region between two periodic arrays of waveguides, each radially directed toward a virtual focal point. The arrays are configured so that their respective foci are located at a predetermined distance away from and outside the free space region to minimize phase errors caused by mutual coupling between adjacent waveguides. Specifically, the focal point of each array connected to each star coupler may be located so that it coincides with the phase center of the other array connected to each coupler. Residual phase errors may be reduced by appropriately setting the lengths of the waveguides in the optical grating between the two star couplers. The length difference between any two adjacent waveguides in the grating is not …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.