Chromatic dispersion measurement and compensation
AssigneeECI Telecom Ltd.
InventorsMark Raymond Zaacks, Uri Mahlab
Life of this patent
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Abstract
The invention proposes a technique for measuring chromatic dispersion in an optical communication line transmitting an optical signal at a predetermined optical wavelength. The technique comprises determining the sign of chromatic dispersion and includes introducing controlled changes of wavelength around the predetermined wavelength, monitoring the optical signal that has passed said line, and obtaining a first and a second signals, wherein the first signal reflects changes of the carrier wavelength, and the second signal reflects changes of delay of the optical signal transmitted via the line. The two signals are compared and the chromatic dispersion sign is determined based on the phase difference there-between.
Claims16
A method for measurement of chromatic dispersion in an optical channel of an optical communication line, suitable for transmitting an optical signal at a predetermined optical wavelength being a carrier wavelength of said optical channel, the method comprising steps of:
- introducing controlled changes of wavelength around said predetermined wavelength,
- monitoring the optical signal that has passed said line, and obtaining from said optical signal:
- a first signal dynamically reflecting changes of the carrier wavelength of said optical signal,
- a second signal dynamically reflecting changes of delay of the same said optical signal transmitted via said line, comparing the first signal with the second signal, and determining the chromatic dispersion sign based on the phase difference between the compared first and second signals.
A system for measurement of chromatic dispersion in an optical channel of an optical line, the system including a receiving node, a transmitting node and the optical line connecting said nodes and intended for transmitting an optical signal at a particular optical carrier wavelength of said optical channel, wherein
- the transmitting node comprises means for controlled changing wavelength of the optical carrier around said particular wavelength at a predetermined manner, and for transmitting the optical signal by said changing optical carrier via the optical line,
- the receiving node comprises:
- means for monitoring dynamic wavelength changes in the optical signal of said optical channel received via the optical line, to produce a first signal,
- means for monitoring dynamic phase changes caused in the optical signal of said optical channel received via the optical line, to produce a second signal;
- a phase comparator for comparing the phase of the first signal to the phase of the second signal to determine the sign of chromatic dispersion in the optical channel of the optical line.
A receiving node equipment suitable for measurement of chromatic dispersion in an optical channel of an optical communication line, while an optical signal is transmitted between a transmitting node and a receiving node at an optical carrier wavelength of said optical channel, wherein said wavelength being controllably changed, the receiving node equipment comprising:
- means for monitoring dynamic changes of the carrier wavelength in said optical signal received via the optical channel of said optical line, to produce a first signal,
- means for monitoring dynamic phase changes in the optical signal received via the optical channel of said optical line, to produce a second signal;
- and
- a phase comparator for comparing the phase of the first signal to the phase of the second signal to determine the sign of chromatic dispersion in the optical channel of said optical line.
Dependencies are inferred from the claim text.