US 2014/0369678 A1Published application

Dual-polarization interferometric optical signal-to-noise ratio monitor

AssigneeFujitsu Limited

InventorsJeng-Yuan Yang, Youichi Akasaka, Motoyoshi Sekiya, Takuji Maeda, Hiroki Ooi, Satoru Okano

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present disclosure includes a method of determining optical signal-to-noise ratio (OSNR) of a signal, comprising separating one polarization component from a plurality of polarization components in an optical signal, selecting one wavelength from a plurality of wavelengths in the optical signal, delaying a first portion of the one polarization component of the one wavelength of the optical signal, shifting a phase of the first portion by a first amount and the first amount plus pi radians, causing the first portion to interfere with a second portion, measuring a power of the interference of the first and second portions, receiving the power of the interference, and comparing the power of the interference when the phase is shifted by the first amount with the interference when the phase is shifted by the first amount plus pi radians to determine OSNR. The present disclosure also includes associated devices.

Claims32

Dependent claims

A device for measuring optical signal-to-noise ratio (OSNR) of an optical signal comprising a plurality of polarization components and a plurality of wavelengths, the device comprising:

a wavelength treatment device configured to select one wavelength from the plurality of wavelengths in the optical signal;
a polarization treatment device configured to:
receive the one wavelength of the optical signal from the wavelength treatment device;
and
separate one polarization component from the plurality of polarization components in the one wavelength of the optical signal;
an interferometer configured to:
delay a first portion of the one polarization component of the one wavelength of the optical signal;
shift a phase of the first portion by a first amount and the first amount plus pi radians;
cause the first portion to interfere with a second portion of the one polarization component of the one wavelength of the optical signal;
and
output interference of the first portion and second portion;
a power meter configured to:
receive the output of the interferometer;
and
measure a power of the output of the interferometer;
and
a controller configured to:
receive the measured power of the output of the interferometer;
and
determine OSNR of the one wavelength of the one polarization component of the optical signal by comparing the power of the output of the interferometer when the interferometer shifts the phase by the first amount with the output of the interferometer when the interferometer shifts the phase by the first amount plus pi radians.

17 more elements

A device for measuring optical signal-to-noise ratio (OSNR) of an optical signal comprising a plurality of polarization components and a plurality of wavelengths, the device comprising:

a polarization treatment device configured to separate one polarization component from the plurality of polarization components in the optical signal;
a wavelength selective switch configured to:
receive the one polarization component of the optical signal;
select one wavelength from the plurality of wavelengths in the one polarization component of the optical signal;
delay a first portion of the one polarization component of the one wavelength of the optical signal;
shift a phase of the first portion by a first amount and the first amount plus pi radians;
cause the first portion to interfere with a second portion of the one polarization component of the one wavelength of the optical signal;
and
output interference of the first portion and second portion;
a power meter configured to:
receive the output of the wavelength selective switch;
and
measure a power of the output of the wavelength selective switch;
and
a controller configured to:
receive the measured power of the output of the wavelength selective switch;
and
determine OSNR of the one wavelength of the one polarization component of the optical signal by comparing the power of the output of the wavelength selective switch when the wavelength selective switch shifts the phase by the first amount with the output of the wavelength selective switch when the wavelength selective switch shifts the phase by the first amount plus pi radians.

15 more elements

A method of determining optical signal-to-noise ratio (OSNR) of an optical signal comprising a plurality of wavelengths and a plurality of polarization components, the method comprising:

separating one polarization component from the plurality of polarization components in the optical signal at a polarization treatment component;
selecting one wavelength from the plurality of wavelengths in the optical signal at a wavelength treatment component;
delaying a first portion of the one polarization component of the one wavelength of the optical signal;
shifting a phase of the first portion by a first amount;
causing the first portion to interfere with a second portion of the one polarization component of the one wavelength of the optical signal;
measuring a power of the interference of the first and second portions of the one polarization component of the one wavelength of the optical signal at a power meter;
receiving at a controller the power of the interference;
delaying the first portion of the one polarization component of the one wavelength of the optical signal;
shifting the phase of the first portion by the first amount plus pi radians;
causing the first portion to interfere with the second portion of the one polarization component of the one wavelength of the optical signal;
measuring the power of the interference of the first and second portions of the one polarization component of the one wavelength of the optical signal at the power meter;
receiving at the controller the power of the interference;
and
determining OSNR by comparing the power of the interference when the phase is shifted by the first amount with the interference when the phase is shifted by the first amount plus pi radians.

11 more elements

Dependencies are inferred from the claim text.