Back to results
US 2002/0159670 A1Published application
Fast-adapting PMD compensator
AssigneeAlcatel
InventorHenning Bulow
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeAlcatel
InventorHenning Bulow
Estimating the term…
A device for adjusting the polarization of an incoming optical signal with a polarization divider (1), a first phase setter (3) in the signal path of at least one of the two output signals from the polarization divider, a first optical coupler (4), a second phase setter (5) in the signal path of at least one of the two output signals from the first optical coupler, and with a second optical coupler (6), an actuating signal being supplied to the phase setters respectively in a feedback loop, said actuating signal being obtained from a quality signal derived from the processed optical signal, is characterized in that a substraction element (10) is provided, to which the two parallel optical signals are supplied from a point after the first optical coupler, a bipolar quality signal being obtained in the substraction element from the difference of the two signals supplied, and that a control element (11) is connected downstream of the substraction element, which control element generates an actuating signal to one of the phase setters that adjusts this such that the amount of the quality signal is minimized and in particular adjusted to zero. This makes it possible for just a single related quality signal to be used for each manipulated variable, and for optimization to be effected by a search for a minimum signal or a balance instead of a maximum search, for the quality signals used to be bipolar, for the appropriate adjusting method to be executed more quickly and simply without complicated sweeping of the manipulated variables and for an inexpensive control logic to be used for the feedback.
Device for adjusting the polarization of an incoming optical signal to a defined polarization state using modulated-up data, with a polarization divider, which processes the incoming optical signal such that two optical signals with orthogonal polarization states are present at its output, with a series-connected first phase setter in the signal path of at least one of the two output signals from the polarization divider, with a first optical coupler, which distributes the light of the two output signals respectively in roughly equal parts to two outputs, with a second phase setter in the signal path of at least one of the two output signals from the first optical coupler, and with a series-connected second optical coupler, an actuating signal being supplied to the first and second phase setter respectively in a feedback loop, said actuating signal being obtained from a quality signal derived from the processed optical signal, wherein a first substraction element is provided, to which the two parallel optical signals are supplied from a point of their signal paths after the first optical coupler, a bipolar quality signal being obtained in the first substraction element from the difference of the two signals supplied, and that a first control element is connected downstream of the first substraction element, which control element generates an actuating signal to one of the phase setters that adjusts the phase setter such that the amount of the quality signal is minimized and in particular adjusted to zero.
Method for adjusting the polarization of an incoming optical signal to a defined polarization state using modulated-up data, with a polarization divider that processes the incoming optical signal such that two optical signals with orthogonal polarization states are present at its output, with a first phase setter connected in series in the signal path of at least one of the two output signals from the polarization divider, with a first optical coupler that distributes the light of the two output signals respectively in roughly equal parts to two outputs, with a second phase setter in the signal path of at least one of the two output signals from the first optical coupler, and with a series-connected second optical coupler, the first and second phase setters being supplied in a feedback loop respectively with an actuating signal that is obtained from a quality signal derived from the optical signal processed, wherein the difference of the two parallel optical signals is formed from a point of their signal paths after the first optical coupler and a bipolar quality signal is obtained from this, from which signal an actuating signal to one of the phase setters is produced that adjusts the phase setter in a feedback loop such that the amount of quality signal is minimized, and in particular adjusted to zero.
Dependencies are inferred from the claim text.