Optical element and light receiving device

Patent metadata

Field	Value
Publication number	US-2016007105-A1
Application number	US-201514730680-A
Country	US
Kind code	A1
Filing date	Jun 4, 2015
Priority date	Jul 7, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

An optical element includes: a polarization splitter that splits light input from an input port into a first signal and a second signal according to a plane of polarization; a polarization rotator that rotates a plane of polarization of the second signal output from the polarization splitter by 90 degrees; a first optical coupler that combines the first signal output from the polarization splitter and the second signal output from the polarization rotator and splits the resultant signal into a third signal and a fourth signal with an equal amplitude; a phase controller that controls a phase of the third signal; and a second optical coupler that combines the third signal output from the phase controller and the fourth signal output from the first optical coupler and splits the resultant signal into a fifth signal and a sixth signal with an equal amplitude.

First claim

What is claimed is:

1 . An optical element comprising:
a polarization splitter that splits light input from an input port into a first signal and a second signal according to a plane of polarization; a polarization rotator that rotates a plane of polarization of the second signal output from the polarization splitter by 90 degrees; a first optical coupler that combines the first signal output from the polarization splitter and the second signal output from the polarization rotator and splits the resultant signal into a third signal and a fourth signal with an equal amplitude; a phase controller that controls a phase of the third signal; and a second optical coupler that combines the third signal output from the phase controller and the fourth signal output from the first optical coupler and splits the resultant signal into a fifth signal and a sixth signal with an equal amplitude.

2 . The optical element according to claim 1 , wherein the phase controller controls the phase of the third signal according to a polarization state of the light input from the input port.

3 . The optical element according to claim 1 , further comprising a photodiode that detects intensity of the fifth signal, wherein the phase controller controls the phase of the third signal according to the intensity detected by the photodiode.

4 . The optical element according to claim 3 , wherein the phase controller controls the phase of the third signal so that the intensity detected by the photodiode becomes equal to or less than a threshold value.

5 . The optical element according to claim 1 , further comprising a multi/demultiplexer, a ring resonator array, an arrayed waveguide grating, or an Echelle diffraction grating to which the sixth signal is input.

6 . A light receiving device comprising:
an optical element; a delayed interferometer-type multi/demultiplexer that demultiplexes the sixth signal into a plurality of wavelength signals; and a light-receiver that receives the plural wavelength signals, wherein the optical element comprising:
a polarization splitter that splits light input from an input port into a first signal and a second signal according to a plane of polarization;
a polarization rotator that rotates a plane of polarization of the second signal output from the polarization splitter by 90 degrees;
a first optical coupler that combines the first signal output from the polarization splitter and the second signal output from the polarization rotator and splits the resultant signal into a third signal and a fourth signal with an equal amplitude;
a phase controller that controls a phase of the third signal; and
a second optical coupler that combines the third signal output from the phase controller and the fourth signal output from the first optical coupler and splits the resultant signal into a fifth signal and a sixth signal with an equal amplitude.

7 . A light receiving device comprising:
an optical element; a delayed interferometer-type multi/demultiplexer that demultiplexes the sixth signal into a plurality of wavelength signals; and a plurality of light receiving photodiodes that receive the plural wavelength signals, wherein the optical element comprising:
a polarization splitter that splits light input from an input port into a first signal and a second signal according to a plane of polarization;
a polarization rotator that rotates a plane of polarization of the second signal output from the polarization splitter by 90 degrees;
a first optical coupler that combines the first signal output from the polarization splitter and the second signal output from the polarization rotator and splits the resultant signal into a third signal and a fourth signal with an equal amplitude;
a phase controller that controls a phase of the third signal;
a second optical coupler that combines the third signal output from the phase controller and the fourth signal output from the first optical coupler and splits the resultant signal into a fifth signal and a sixth signal with an equal amplitude; and
a photodiode that detects intensity of the fifth signal,
the phase controller controls the phase of the third signal according to the intensity detected by the photodiode, and the photodiode that detects the intensity of the fifth signal and the plurality of light receiving photodiodes are included in a photodiode array.

Assignees

• Fujitsu Ltd
• Photonics Electronics Technology Res Ass

Inventors

• Jeong Seokhwan

Classifications

• H04Q2011/0015

  using splitting combining · CPC title

• H04B10/0795

  Performance monitoring; Measurement of transmission parameters · CPC title

• H04Q2011/0035

  using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical · CPC title

• H04Q2011/0016

  using wavelength multiplexing or demultiplexing · CPC title

• H04B10/60

  Receivers · CPC title