US 5,611,005 A · High-speed polarization scrambler with adjustable chirp

Abstract

Two separate electrooptic phase modulators are used in a modified Mach-Zehnder interferometer to vary the absolute and relative optical phases of two orthogonally polarized modes of an input signal independently of each other. A conventional Y-branch splitter on lithium niobate splits the input signal equally into the two waveguide phase modulators and an external polarization splitter recombines the two phase modulated signals in orthogonal polarization states. The polarization in the interferometer is maintained by connecting the outputs of the two phase modulators to polarization maintaining fibers. An alternate embodiment of the present invention uses an additional 3-dB directional coupler to mix the two phase modulated signals before they are combined in orthogonal polarization states.

Claims18

Dependent claims

A high-speed polarization scrambler for modulating the phase and the state of polarization of a polarization signal, comprising:

input signal means;
an optical splitter means to split the input signal into at least a first and a second input signal branches;
at least a first and a second optic phase modulators connected to the first and second input signal branches, respectively;
and
an optical polarization combiner connected to an output of the first and second phase modulators, wherein the combiner combines said outputs of the first and second phase modulators in two mutually orthogonal polarization states;
wherein the first and second phase modulators independently modulate the optical phases of the input signals in said first and second input signal branches.

3 more elements

Dependencies are inferred from the claim text.

High-speed polarization scrambler with adjustable chirp

Life of this patent

High-speed polarization scrambler with adjustable chirp

Life of this patent

Abstract

Claims18