Optical modulator for cancellation of second-order intermodulation products in lightwave systems
US5239401A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 31, 1990 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | Dec 31, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/19
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Optical communication methods and apparatus are disclosed for transmitting two or more optical signals with different optical carrier frequencies on a single optical fiber with high spectral efficiency. Each optical carrier is typically modulated with multiple modulated subcarriers. In one embodiment, an optical phase modulator provides cancellation of second order intermodulation products in each optical signal, thereby permitting the optical carrier frequencies to be spaced by 2f.sub.max, where f.sub.max is the maximum modulation frequency. In another embodiment, a single sideband optical phase modulator provides cancellation of second order intermodulation products and one signal sideband, thereby permitting the optical carrier frequencies to be spaced by f.sub.max.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.