Patent · US Expired

Method and device for spectral level balancing in wavelength division multiplex multi-channel systems

US6563980B1 · kind B1 · utility

3Cited by

5References

1Claims

0Family size

Assignee

DEUTSCHE TELEKOM AG · DE

Inventors

Wolfgang Dultz · Frankfurt am Main, DE
Leonid A. Beresnev · Dayton, US
Reinald Ries · Darmstadt, DE

Key dates

Filing date	Apr 14, 2000
Grant date	May 13, 2003
Priority date	—
Expiry date	Apr 14, 2020

Classification

Technology area (CPC G)Physics
CPC primaryG02B6/29395
WIPO fieldOptics
WIPO sectorInstruments

Abstract

WDM multi-channel systems for large distances having a number of intensifiers may cause an increase in intensifications, which lead to considerable differences in intensity, even given modest wavelength dependence, making spectral leveling maybe necessary. The light from the fiber is first spectrally into channels, and, thus locally separated, projected onto the surface of an optic limiter based on an OASLM (optical addressed, spatial light modulator), in which the intensive channels are overproportionally attenuated. The tension dependence of liquid crystal cells, derived from exposure, is used to level the WDM channels. Lastly, the channels are again imaged onto a point and coupled into another fiber. The invention is used in WDM multi-channel systems for large distances a number of intensifiers.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.