Wavelength selective switch

Patent metadata

Field	Value
Publication number	US-9762983-B2
Application number	US-201615043828-A
Country	US
Kind code	B2
Filing date	Feb 15, 2016
Priority date	Aug 22, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A wavelength selective switch includes: N input ports, an input-side fiber array, an input-side collimator array, an input-side beam deformation and polarization conversion component, an input-side wave-demultiplexing component, an input-side switching engine, a focusing transformation lens group, an output-side switching engine, an output-side wave-combining component, an output-side beam deformation and polarization conversion component, an output-side collimator array, an output-side fiber array, and M output ports. The focusing transformation lens group includes two identical aspheric convex lenses that are placed in parallel, where a curvature from a center to an edge of a surface of the aspheric convex lens changes continuously. A spatial position of the focusing transformation lens group and the curvature from the center to the edge of the surface are so set that light with different wavelengths from the input-side switching engine is focused to a corresponding position of the output-side switching engine respectively.

First claim

What is claimed is:

1. A wavelength selective switch (WSS), comprising:
N input ports, wherein N is a natural number greater than 1;
an input-side fiber array connected to the N input ports;
an input-side collimator array connected to the input-side fiber array;
an input-side beam deformation and polarization conversion component connected to the input-side collimator array;
an input-side wave-demultiplexing component connected to the input-side beam deformation and polarization conversion component;
an input-side switching engine connected to the input-side wave-demultiplexing component;
a focusing transformation lens group connected to the input-side switching engine and comprising two identical aspheric convex lenses that are placed in parallel, wherein a curvature from a center to an edge of a surface of the aspheric convex lenses changes continuously, and is used to control focal lengths of light with different wavelengths, wherein a spatial position of the focusing transformation lens group and the curvature from the center to the edge of the surface of the aspheric convex lenses are so set that light with different wavelengths from the input-side switching engine is focused to a corresponding position of an output-side switching engine respectively, the output-side switching engine connected to the focusing transformation lens group;
an output-side wave-combining component connected to the output-side switching engine;
an output-side beam deformation and polarization conversion component connected to the output-side wave-combining component;
an output-side collimator array connected to the output-side beam deformation and polarization conversion component;
an output-side fiber array connected to the output-side collimator array;
M output ports, wherein M is a natural number greater than 1;
wherein the input-side wave-demultiplexing component comprises:
a diffraction grating,
a dispersion compensation prism, and
a focusing convex lens, wherein:
the diffraction grating is configured to separate, according to different wavelengths, light from the input-side beam deformation and polarization conversion component,
the dispersion compensation prism is configured to perform dispersion compensation on the light that is separated by the diffraction grating,
the focusing convex lens is configured to collimate light with different wavelengths from the diffraction grating, and converge single-wavelength light from the diffraction grating, and
spatial positions of the diffraction grating, the dispersion compensation prism, and the focusing convex lens are such that input light whose frequency intervals are equal is converted into light that is parallel in space and equally spaced in a direction that is perpendicular to an arrangement direction of the input-side fiber array.

2. The WSS according to claim 1 , wherein the input-side fiber array and the output-side fiber array are arranged in two parallel columns along a direction but at different positions.

3. The WSS according to claim 1 , wherein:
the input-side beam deformation and polarization conversion component comprises a polarization splitting component, at least one prism, and a half-wave plate that are arranged in sequence, wherein the polarization splitting component is configured to convert unpolarized light from the collimator array into two beams of polarized light whose transmission directions are parallel and whose polarization directions are perpendicular to each other;
the at least one prism is configured to enlarge a size of a light spot of the polarized light and a distance between the two beams of polarized light whose transmission directions are parallel and whose polarization directions are perpendicular to each other; and
a spatial position of the half-wave plate is so set that one beam of polarized light of the two beams of polarized light whose transmission directions are parallel and whose polarization directions are perpendicular to each other passes through the half-wave plate, and the other beam of polarized light does not pass through the half-wave plate.

4. The WSS according to claim 1 , further comprising a controller, configured to control an angle by which light is deflected by the input-side switching engine and/or the output-side switching engine.

5. The WSS according to claim 1 , wherein the output-side switching engine and the output-side fiber array form an included angle greater than 0 degrees and smaller than 5 degrees.

6. The WSS according to claim 1 , wherein:
the output-side switching engine is liquid crystal on silicon (LCOS), the LCOS comprises multiple deflection passbands that correspond to light with different frequencies respectively, a gap exists between the multiple deflection passbands that correspond to light with different frequencies respectively, and pixels in the gap are set to invalid pixels.

7. The WSS according to claim 1 , wherein each aspheric convex lens is a doublet convex lens.

8. The WSS according to claim 1 , wherein N is equal to M.

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhao Han
• Zong Liangjia

Classifications

• H04Q11/0005 Primary

  Switch and router aspects · CPC title

• G02B6/29373

  utilising a bulk dispersive element, e.g. prism · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G02B6/2706

  as bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters · CPC title

• G02B6/3512

  the optical element being reflective, e.g. mirror · CPC title