High-speed electro-optic modulator
US6330097A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1999 |
| Grant date | Dec 11, 2001 |
| Priority date | — |
| Expiry date | Apr 8, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/48
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical modulator is provided to control the intensity of a transmitted or reflected light. In a transmission mode, a separator splits arbitrarily polarized light into two polarization rays and one is made to travel a separate path from the other. A recombiner causes the two rays to recombine at an output unless an electro-optic phase retarder changes the polarization of the two rays, in which case, both of them miss the output by an amount which is a function of the voltage on the retarder. A normally-off version with low polarization mode dispersion is obtained by changing the orientation of the recombiner. A normally-on version with low polarization mode dispersion is obtained with a passive polarization direction rotator. Similar results can be obtained in a reflection mode where the input and output are on the same side of the modulator. Versions using a GRIN lens are particularly suited to modulation of light out of and back into fiber-optic cables. The device can be operated as a variable optical attenuator, an optical switch, or a high speed modulator and is insensitive to polarization of the input light. A preferred material for the phase retarder is a hot-pressed ceram…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.