Deutschetelekom Ag

Deutsche Telekom Ag Bonn

Erna Frins

Wolfgang Dultz

Heidrun Schmitzer

Gisela Dultz

Gerald Meltz

Leonid Alexseevich Beresnev

Hans Wilfried Koops

Joachim Vobian

Werner Weiershausen

Franko Kueppers

Bernd Hils

A method and device for reducing the distortion of optical pulses caused by the polarization mode dispersion in optical communication systems is provided. When an optical pulse having any polarization is transmitted through an optical communication system, which is optically anisotropic, at least in sections, the optical pulse may become distorted due to the different velocities of the various polarization components. This distortion of the optical pulses may reduces the maximum transmission rate of the system. A method is provided for functioning in response to the detected transmission quality of the communication system where a polarization-controlling device for setting the polarization of the optical pulse is driven in such a way that the transmission quality is maximized. An optical communication system, including an optical transmission medium, involves a device for determining the transmission quality of the communication system, a regulating device, and a polarization-controlling device. The output signal from the device for determining the transmission quality of the communication system may be applied to the regulating device, which drives the polarization-controlling device to change the polarization of the optical pulses in such a way that the transmission quality is optimized.

Reducing the distortion of optical pulses caused by polarization mode dispersion in optical communication systems

The present invention provides an optical communications link having at least one optical fiber, in particular for communications transmission, where the optical fiber is repeatedly bent. The fiber sections having a right-hand and left-hand curvature are distributed in such a way over the communications link that the average torsion of the fiber is approximately zero. The communications link in accordance with the present invention is compact, flexible, and variable in length. In addition, it reduces the sensitivity of the polarization state of the optical signal to changes in the form of the communications link.

Optical communications link

The present invention is directed to a sensor for detecting changes in the distance between a first and a second location, having at, least one substantially helically coiled optical fiber, which is able to be mechanically connected to at least one of the locations, and having a light transmitter and a detecting device for optical signals, the detecting device being able to generate an output signal, which is dependent upon the polarization state of the optical signal transmitted via the optical fiber. The present invention is also directed to a method for detecting the changes in distance between a first and a second location, having the following features: at least one of the locations is mechanically coupled to a substantially helically coiled optical fiber; an optical signal having a known polarization state is launched into the optical fiber; following transmission over the connecting line, this is detected in such a way that information is obtained with respect to its polarization state; from this information, the change in distance is determined.

Sensor and method for detecting changes in distance

A double-beam interferometer for electromagnetic radiation and a method for the compensation of dispersion or increase in the spectral resolution of such an interferometer. Using a polarizer, which is brought into the optical radiation path, a defined polarization state P,is produced for the electromagnetic partial waves flowing into the arms of the interferometer. This polarization state is wavelength-independent and can vary for both partial beams. Optical elements modify the polarization state P,of the electromagnetic partial waves as a function of wavelength &lgr; and each spectral component &lgr;,is coded with a polarization P,(&lgr;i). An analyzer, fitted to the output of the interferometer, transmits an adjustable polarization state P,, whereby an additional wavelength-dependent phase difference &ggr;(&lgr;) occurs between the partial waves of the spectral components. &ggr;(&lgr;) can be adjusted to obtain compensation of dispersion or an increase in the spectral resolution of the interferometer.

Interferometer and methods for compensation of dispersion or increase in spectral resolution of such an interferometer

A telecommunication system having frequency-dividing optical components where light pulses having different frequencies are coupled out of a optical fiber by fiber grating and/or photonic crystals and imaged by focusing elements outside of the optical fiber. The fiber grating for different frequencies can be used in a single period or in different periods disposed one after the other. The photonic crystals can be used at the optical fiber extremity or etched in a channel or trench in a glass fiber. Delay elements are added to ensure that different frequency light pulses are imaged simultaneously in a given and desired time relation as required for further parallel processing.

Growing community of inventors

Montevideo, Uruguay

Erna Frins