US 9,432,118 B2Granted

Apparatus and a method for generating, compensating and emulating polarization mode dispersion

AssigneeOki Electric Industry Co., Ltd.

InventorYoshihiro Kanda

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Abstract

A polarization mode dispersion (PMD) generating apparatus includes a polarization plane controller; a unit function block including a first differential group delay (DGD) generator, a first mode mixer, and a second DGD generator, a second mode mixer and a reflective mirror, which are arranged in this order from the input side of input light free from PMD. Part of the first and second DGD generators is disposed on a driven stage to modify the optical path length. The input light has polarization converted by the polarization plane controller and is inputted to the first DGD generator to propagate back and forth on an optical path from the unit function block through the second mode mixer to the reflective mirror. In the PMD-generating apparatus, the driven stage adjusts a DGD amount between orthogonal eigen-polarization modes generated in the first and second DGD generators on the basis of an applicable wavelength band.

Claims12

Dependent claims

A polarization mode dispersion (PMD) generating apparatus including a first differential group delay (DGD) generator, a first mode mixer, a second DGD generator, a second mode mixer, and a reflective mirror, which are arranged in this order, wherein

each of said first and second DGD generators includes a DGD adjustment mechanism variably adjusting a DGD amount between orthogonal eigen-polarization modes generated in said first and second DGD generators, respectively, and
input signal light is inputted from said first DGD generator to propagate back and forth on an optical path from said first DGD generator through said first mode mixer, said second DGD generator and said second mode mixer to said reflective mirror,
whereby a first-order PMD is added to the input signal light with a second-order PMD canceled which was raised along with generation of the first-order PMD to generate a PMD-added optical signal;
and
wherein
said DGD adjustment mechanisms include a first DGD adjustment mechanism adjusting a DGD amount generated in said first DGD generator and a second DGD adjustment mechanism adjusting a DGD amount generated in said second DGD generator,
said first and second DGD adjustment mechanisms are in integral with each other to adjust the DGD amounts, and
each of said first and second DGD adjustment mechanisms is in a form of Mach-Zehnder interferometer.

5 more elements

each of said first and second DGD generators includes a DGD adjustment mechanism variably adjusting a DGD amount between orthogonal eigen-polarization modes generated in said first and second DGD generators, respectively, and
input signal light is inputted from said first DGD generator to propagate back and forth on an optical path from said first DGD generator through said first mode mixer, said second DGD generator and said second mode mixer to said reflective mirror,
whereby a first-order PMD is added to the input signal light with a second-order PMD canceled which was raised along with generation of the first-order PMD to generate a PMD-added optical signal;
and
wherein
said DGD adjustment mechanisms include a first DGD adjustment mechanism adjusting a DGD amount generated in said first DGD generator and a second DGD adjustment mechanism adjusting a DGD amount generated in said second DGD generator,
said first and second DGD adjustment mechanisms are in integral with each other to adjust the DGD amounts, and
each of said first and second DGD adjustment mechanisms is in a form of Michelson interferometer.

5 more elements

each of said first and second DGD generators includes a DGD adjustment mechanism variably adjusting a DGD amount between orthogonal eigen-polarization modes generated in said first and second DGD generators, respectively, and
input signal light is inputted from said first DGD generator to propagate back and forth on an optical path from said first DGD generator through said first mode mixer, said second DGD generator and said second mode mixer to said reflective mirror,
whereby a first-order PMD is added to the input signal light with a second-order PMD canceled which was raised along with generation of the first-order PMD to generate a PMD-added optical signal;
and
wherein
said DGD adjustment mechanisms include a first DGD adjustment mechanism adjusting a DGD amount generated in said first DGD generator and a second DGD adjustment mechanism adjusting a DGD amount generated in said second DGD generator,
said first and second DGD adjustment mechanisms are in integral with each other to adjust the DGD amounts, and
each of said first and second DGD generators includes:
a plurality of birefringent media arranged in series and generating different DGD amounts from one another;
and
90-degree variable polarization rotators arranged between said birefringent media to rotate and switch by 90 degrees electric-field components in directions of fast and slow axes of light propagating through crystal of said birefringent medium.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/536,996Filed 28 Jun 2012
Priority: JP 2011-21414329 Sep 2011
Published: US 2013/0083393 A14 Apr 2013
Granted: 30 Aug 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04B 10/2569
For the reduction or elimination of distortion or dispersion: due to polarisation mode dispersion [PMD]
G02B 27/286
For polarising: for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another
H04B
Transmission
G02B
Optical elements, systems or apparatus