Method and system for equalizing PMD using incremental delay switching
First Claim
1. A system for compensating for polarization mode dispersion in an optical data signal traveling through an optical fiber comprising:
- a polarization mode separator which separates the optical data signal into first and second polarized optical signals traveling along respective first and second optical paths;
a first variable switching delay element located along said first optical path for providing a first incremental propagation delay to said first polarized optical signal;
a second variable switching delay element located along said second path for providing a second incremental propagation delay to said second polarized optical signal;
a controller coupled to said first and second variable switching delay elements, said controller controls said first and second switching delay elements such that said first and second polarized optical signals have a relative propagation delay that compensates for polarization mode dispersion, said relative propagation delay corresponding to the difference between said first and second incremental propagation delays; and
a beam combiner, optically coupled to said first and second optical paths downstream of said first and second variable switching delay elements, said beam combiner combining said first and second polarized optical signals output respectively from said first and second variable switching delay elements to form an optical output data signal compensated for polarization mode dispersion.
3 Assignments
0 Petitions
Accused Products
Abstract
A polarization mode compensation system and method using optical switch elements to establish incremental delays between different polarization modes of an optical data signal is provided. A polarization mode separator separates the optical data signal into first and second orthogonally polarized optical signals. A first variable switching delay element provides a first incremental propagation delay for the first polarized optical signal. A second variable switching delay element provides a second incremental propagation delay for the second polarized optical signal. The first and second variable switching delay elements consist of a series of optical switches optically interconnected by different incremental lengths of optical fiber. For example, 2×2 optical switches are provided for switching between a reference fiber segment and a respective delay fiber segment to provide a relative incremental propagation delay. A controller controls optical switches in the first and second variable switching delay elements to set first and second incremental propagation delays. In particular, the first and second polarized optical signals are incrementally delayed relative to one another so as to compensate for polarization mode dispersion. A beam combiner then combines the first and second polarized optical signals to form an optical output data signal which can be detected accurately by a receiver without the effects of polarization mode dispersion. In this way, optical data signals can be reliably transmitted over greater distances along a long-haul fiber optic dispersive medium at even greater bit-rates and bandwidth.
64 Citations
13 Claims
-
1. A system for compensating for polarization mode dispersion in an optical data signal traveling through an optical fiber comprising:
-
a polarization mode separator which separates the optical data signal into first and second polarized optical signals traveling along respective first and second optical paths; a first variable switching delay element located along said first optical path for providing a first incremental propagation delay to said first polarized optical signal; a second variable switching delay element located along said second path for providing a second incremental propagation delay to said second polarized optical signal; a controller coupled to said first and second variable switching delay elements, said controller controls said first and second switching delay elements such that said first and second polarized optical signals have a relative propagation delay that compensates for polarization mode dispersion, said relative propagation delay corresponding to the difference between said first and second incremental propagation delays; and a beam combiner, optically coupled to said first and second optical paths downstream of said first and second variable switching delay elements, said beam combiner combining said first and second polarized optical signals output respectively from said first and second variable switching delay elements to form an optical output data signal compensated for polarization mode dispersion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for compensating for polarization mode dispersion in an optical data signal traveling through an optical fiber comprising the steps of:
-
separating the optical data signal into first and second polarized optical signals; outputting said first and second polarized optical signals along respective first and second optical paths; optically switching said first polarized optical signal to provide an incremental relative propagation delay between said first and second polarized optical signals which compensates for polarization mode dispersion; and combining said first and second polarized optical signals to form an optical output data signal compensated for polarization mode dispersion. - View Dependent Claims (12, 13)
-
Specification
-
- Resources
-
Current AssigneeVerizon Patent and Licensing Incorporated (Verizon Communications Inc.)
-
Original AssigneeMCI Communications Corporation (Verizon Communications Inc.)
-
InventorsRobinson, Andrew Niall, Fee, John A.
-
Primary Examiner(s)NEGASH, KINFE MICHAEL
-
Application NumberUS08/670,686Time in Patent Office839 DaysField of Search359/122, 359/140, 359/156, 359/161, 250/227.12US Class Current398/147CPC Class CodesH04B 10/2569 due to polarisation mode di...
