Patent ID: 6271952
Filing Date: 2001-08-07
Classification: H04B

Abstract:
Apparatus for compensating for polarisation mode dispersion in an optical signal transmitted via an optical waveguide of an optical communications system, the apparatus comprising;separating means operable to separate the optical signal into first and second components having a dispersion delay therebetween;delay means operable to delay the first and second components by respective delays differing by a delay increment;recombining means operable to recombine the delayed first and second components to form an output signal; andcontrol means operable to control the delay increment such that in the output signal the dispersion delay is substantially compensated by the delay increment;wherein the delay means comprises at least one delay line having a chirped Bragg reflector extending longitudinally of the delay line, wherein said respective delay results from a time taken for said respective component to traverse the delay line to and from a reflection position at which Bragg reflection occurs, and wherein the control means is operable to variably regulate at least one parameter determining the conditions under which Bragg reflection occurs to variably define the reflection position relative to the Bragg reflector.