KR101929472B1 - Wavelength selective switch - Google Patents

Abstract

An invention relating to a wavelength selection switch is disclosed. A wavelength selection switch of the present invention comprises: a switching lens unit for crossing an optical beam transmitted in an input port array on a switching axis; A light expanding unit for expanding the beam size of the optical beam output from the switching lens unit in the direction of the dispersion axis; A light splitting unit for splitting an optical beam having a beam size expanded in the optical expanding unit at different angles on a dispersion axis according to a wavelength component; An image lens unit for redirecting and focusing the separated wavelength of the optical beam; And a switching unit for shifting an angle of the wavelength selected on the switching axis to transmit the selected wavelengths to the independently selected output port array in the plurality of wavelength channels.

Description

Wavelength Select Switch {WAVELENGTH SELECTIVE SWITCH}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength selection switch, and more particularly, to a wavelength selection switch capable of reducing the size of a wavelength selection switch and reducing the number of components used.

In general, the wavelength selective switch expands the optical beam output from the input port on a dispersion axis, and then enters the diffraction grating. In the diffraction grating, the optical beam is split into a plurality of wavelengths. The optical beam split by the diffraction grating is incident on the switching unit. In the switching unit, the optical beam is incident on the corresponding output port array as the optical beam is set or steered at a predetermined angle for each wavelength.

However, in the conventional wavelength selection switch, since a plurality of large-diameter image lenses are provided to extend the optical beam and focus the optical beam on the switching unit, there is a problem that the complexity increases and the size and the number of components of the wavelength selection switch increase .

BACKGROUND OF THE INVENTION [0002] The background art of the present invention is disclosed in U.S. Patent Publication No. 8190025 (Registered on May 29, 2012, entitled "Selective Switch Wavelength with Characteristic Planes of Operation").

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wavelength selection switch capable of reducing the size of a wavelength selection switch and reducing the number of components to be used.

A wavelength selection switch according to the present invention includes: a switching lens unit for crossing an optical beam transmitted from an input / output port array on a switching axis; A light expanding unit for expanding the beam size of the optical beam output from the switching lens unit in the direction of the dispersion axis; A splitter for splitting an optical beam having a beam size expanded by the optical expander at different angles on a dispersion axis according to a wavelength component; An image lens unit for redirecting and focusing the separated wavelength of the optical beam; And a switching unit for shifting an angle of the wavelength selected on the switching axis to transmit the selected wavelengths to the independently selected output port array in the plurality of wavelength channels.

The wavelength selection switch may further comprise a polarization optical section that splits any polarized light transmitted from the input port array into two optical beams having the same polarization state and arranges the separated two optical beams on the dispersion axis have.

The switching lens unit may be a cylindrical lens having a curvature on the switching axis.

The wavelength selection switch may further include a collimator lens for collimating an optical beam emitted from the input port array on the dispersion axis side with respect to the input port array side of the switching lens section.

The light expansions may include a pair of lenses having different focal lengths.

The optical expanding portion may include at least one cylindrical lens having a curvature on the dispersion axis.

The image lens portion may function as a light-expanding lens on the dispersion axis at the optical expanding portion.

The image lens unit may be used as a relay lens for relaying an intersection point of the input / output unit caused by the switching lens unit on the switching axis.

When the optical beam is first incident on the image lens unit, the image lens unit may function as an optical expansion lens on the dispersion axis, and may serve as a first relay lens on the switching axis.

When an optical beam is secondarily incident on the image lens unit from the light splitting unit, the image lens unit may function as an image lens on the dispersion axis, and may serve as a second relay lens on the switching axis.

Wherein when the optical beam is firstly incident on the image lens unit, the image lens unit functions as an optical expansion lens on the dispersion axis, acts as a first relay lens on the switching axis, When the optical beam is incident on the second lens unit, the image lens unit serves as an image lens on the dispersion axis, and may serve as a second relay lens on the switching axis.

The switching unit may include a plurality of switching channel units for generating an angle to transmit the optical beam output from the image lens unit to the output port array selected for each wavelength.

According to the present invention, since one image lens unit simultaneously performs the telescopic function, the focusing function, and the relay function of the switching axis of the dispersion axis, the number of components required for the configuration is reduced in the wavelength selection switch, . In addition, it is possible to prevent an assembly error of each component from occurring.

In addition, according to the present invention, since one image lens unit is provided in the wavelength selection switch, it is possible to prevent the occurrence of a yarn area caused by processing and coating of optical components, thereby reducing the size.

Further, according to the present invention, since the optical expansion unit increases the beam size of the optical beam output from the switching lens unit in the dispersion axis direction, the beam spot size of the optical beam focused on the switching unit is reduced in the dispersion axis direction. Accordingly, it is possible to prevent neighboring beam spots from overlapping each other, and more beam spots can be focused on the switching channel portion of the switching unit of a limited size, thereby increasing the independence between adjacent wavelength channels at the time of port switching per wavelength.

1 is a block diagram schematically showing a wavelength selection switch according to an embodiment of the present invention.
2 is a configuration diagram showing a state in which a wavelength selection switch according to an embodiment of the present invention is developed on a dispersion axis and a switching axis.
FIG. 3 is a configuration diagram illustrating a state where an optical beam is switched to an input / output port according to wavelengths in a wavelength selection switch according to an embodiment of the present invention.
FIG. 4 is a diagram showing a state in which an optical beam is expanded in a wavelength selection switch according to an embodiment of the present invention.
5 is a configuration diagram illustrating a process of changing the beam size of an optical beam by wavelength in a wavelength selection switch according to an embodiment of the present invention.
6 is a configuration diagram illustrating a state in which a beam spot of an optical beam is focused on a switching channel unit in a wavelength selection switch according to an embodiment of the present invention.

Hereinafter, an embodiment of a wavelength selection switch according to the present invention will be described with reference to the accompanying drawings. In the course of describing the wavelength selection switch, the thicknesses of the lines and the sizes of the constituent elements shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a configuration diagram schematically showing a wavelength selection switch according to an embodiment of the present invention. FIG. 2 shows a state in which a wavelength selection switch according to an embodiment of the present invention is developed on a dispersion axis and a switching axis FIG. 3 is a configuration diagram illustrating a state in which an optical beam is switched to an input / output port different for each wavelength in a wavelength selection switch according to an embodiment of the present invention. FIG. FIG. 5 is a diagram illustrating a process of changing the beam size of an optical beam by wavelength in a wavelength selection switch according to an embodiment of the present invention, and FIG. 5 6 is a configuration diagram illustrating a state in which a beam spot of an optical beam is focused on a switching channel unit in a wavelength selection switch according to an embodiment of the present invention.

1 to 6, a wavelength selection switch according to an embodiment of the present invention includes a switching lens unit 120, a light expanding unit 130a, a light splitting unit 150, an image lens unit 130b, (160).

The wavelength selection switch disperses, diffracts, focuses, and angularizes the optical beam with respect to a dispersion axis and a switching axis. The dispersion axis may be formed perpendicular or non-perpendicular to the switching axis.

The wavelength selection switch includes a collimation lens (111). The collimator lens 111 is disposed on the input / output port array 50, 60 side of the switching lens section 120 and collimates the optical beam spreading from the input port section 50 onto the dispersion axis. Here, the collimation means adjusting the optical beam spreading at a certain angle in parallel along the optical path. The optical beam transmitted through the collimator lens 111 is transmitted to the polarization optical unit 110. [

The polarization optical unit 110 is disposed between the switching lens unit 120 and the input / output port arrays 50 and 60. The polarization optical unit 110 splits any polarized light transmitted from the input port unit 50 into two beams having the same polarization state and arranges the two separated beams on the dispersion axis.

The polarization optical part 110 includes a birefringent crystal part 113 and a half wave plate 114. The optical beam transmitted through the birefringent crystal part 113 is separated into a beam parallel to the dispersion axis and a beam parallel to the switching axis. The beam parallel to the switching axis is changed into a beam parallel to the dispersion axis while transmitting through the half-wave plate 114. The two separated beams are arranged on the dispersion axis.

The switching lens unit 120 crosses the optical beam transmitted from the input / output port units 50 and 60 on the switching axis.

The switching lens unit 120 may be a cylindrical lens having a curvature on the switching axis. Since the switching lens section 120 is formed to have a curvature on the switching axis, the optical beam can be crossed on the switching axis. Further, by adjusting the curvature of the switching lens unit 120, the focal length of the switching lens unit 120 can be adjusted. Here, the cylindrical lens means a lens in which a plane is formed on one side and a surface having a curvature is formed on the other side.

The switching lens section 120 may be disposed after the polarizing optical section 110 and the collimating lens 111 may be disposed between the polarizing optical section 110 and the input and output port arrays 50 and 60. [ Alternatively, both the switching lens unit 120 and the collimator lens 111 may be disposed between the polarization optical unit 110 and the input / output port arrays 50 and 60.

The optical expander 130a expands the beam size of the optical beam output from the switching lens unit 120 in the direction of the dispersion axis.

The optical expander 130a includes a first optical extension lens 131 and an image lens unit 133 serving as a second optical extension lens. The first optical expansion lens 131 may be a cylindrical lens having a curvature on a dispersion axis. The optical extender 130a expands the optical beam in the direction of the dispersion axis in a telescopic manner of the two lenses to increase the beam size. At this time, the beam size of the optical beam increases in the direction of the dispersion axis (D: see Fig. 4), but the beam size does not increase in the direction of the switching axis. Here, the telescopic system means that two lenses are arranged with a distance of focal distance from each other.

As the beam size D of the optical beam incident on the image lens unit 133 is greatly increased, the size of the beam spot S of the optical beam focused on the switching unit 160 can be further reduced. At this time, as the beam spot size of the optical beam becomes smaller in the direction of the dispersion axis, the adjacent beam spots S in the switching channel unit 161 of the switching unit 160 are prevented from overlapping each other can do.

The image lens unit 133 redirects and focuses the optical beam separated at different angles for each wavelength in the light splitting unit 150. [ The image lens unit 133 may be formed of one or more lenses. The input / output optical path of the light splitting unit 150 is disposed adjacent to the image lens unit 133, and the image lens unit 133 functions as an optical expansion lens on the dispersion axis.

When the optical beam is first incident on the image lens unit 133, the image lens unit 133 serves as the optical expansion lens 130a on the dispersion axis and serves as the first relay lens 130b on the switching axis do.

When the optical beam is secondarily incident on the image lens unit 133 from the light splitting unit 150, the image lens unit 133 serves as an image lens on the dispersion axis, and on the switching axis, the second relay lens 130b ).

In this way, the image lens unit 133 expands the optical beam incident on the light splitting unit 150 in the direction of the dispersion axis, focuses the optical beam incident on the switching unit 160 in the dispersion axis direction, Relay the intersection of the switching axis input / output light.

Here, the relay means to transmit the optical characteristics such as the beam size, the beam size, and the traveling direction of the optical beam as it is. In addition, the focusing function means that the optical beam is incident on the switching channel unit 161 of the switching unit 160 as a beam spot S having a small size for each of the separated wavelengths.

One image lens unit 133 performs the function of the optical expanding lens 130a and the focusing function on the dispersion axis and performs the function of the relay lens 130b on the switching axis so that a plurality of lens units are not provided in the wavelength selection switch do. Therefore, the size of the wavelength selection switch can be reduced.

Further, when a plurality of lens portions are provided on the optical path, a sufficient distance must be secured between the plurality of lens portions, so that the area of the optical system must be increased. However, according to the embodiment of the present invention, since one image lens portion 133 is disposed on the optical path, the area of the optical system can be relatively reduced.

The optical distributor 150 separates the optical beam whose beam size has been enlarged in the optical expander 130a at different angles on the dispersion axis according to the wavelength component. The spectroscopic section 150 includes a prism section 151 and a diffraction grating section 153 (grating). The prism portion 151 and the diffraction grating portion 153 may be integrally formed or separately formed.

The optical beam reflected by the optical fiber 150 passes through the image lens unit 133 and is incident on the switching unit 160. At this time, since the optical beam having the beam size expanded in the direction of the dispersion axis in the optical expanding part 130a is focused on the switching part 160 by the image lens part 133, the size of the switching part 160 in the direction of the dispersion axis The beam spot S to be reduced is focused.

In Fig. 4, A1 is an optical beam before being incident on the optical expander 130a, A2 is an optical beam whose size is increased in the dispersion axis direction when it is incident on the image lens unit 133, S is a switching unit 160 The size of the dispersion axis direction is significantly reduced from the size of the switching axis direction.

The optical beam of the desired wavelength can be transmitted to the output port array 60 since the beam spots S separated by wavelength can be prevented from overlapping each other in the switching unit 160. [

The switching unit 160 angularly displaces the selected wavelengths to transmit the selected wavelengths in the plurality of wavelength channels to the independently selected output ports. The switching unit 160 includes a plurality of switching channel units 161 for reflecting the optical beam output from the image lens unit 133 by wavelength. The switching channel unit 161 operates at a specific wavelength as the power source is applied to displace an angle of a specific wavelength. The switching channel unit 161 can change the optical path by generating a phase slope on the switching axis in liquid crystal on silicon (LCoS).

The plurality of wavelength channels independently angularly displaced by the switching unit 160 are output to the output port array 60 through the same path as the optical beam incident path. That is, a plurality of wavelength channels angularly displaced by the switching unit 160 are transmitted through the image lens unit 133, the light splitting unit 150, the image lens unit 133, the optical extender 130, the polarization optical unit 110, And then output to the output port array 60 through the collimator lens 111 sequentially.

The output port array 60 can be configured as one component with the input port array 50 and can be configured as a separate component. Although only five ports are shown in the figure for the convenience of explanation, the number of ports may be as many as required according to the embodiment.

As described above, since the single image lens unit 133 simultaneously performs the optical expanding function, the focusing function, and the relay function of the switching axis of the dispersion axis, the number of lens units to be installed in the wavelength selection switch is reduced, It is possible to reduce the dead area of the generated lens, thereby reducing the size of the wavelength selection switch. Also, it is possible to prevent an assembly error of the image lens unit 133 from being generated.

Further, since the beam expanding portion 130a increases the beam size of the optical beam output from the switching lens portion 120 in the direction of the dispersion axis, the beam spot size of the optical beam incident on the switching portion 160 increases . Therefore, it is possible to prevent overlapping of neighboring beam spots in the switching channel unit 161, and more beam spots can be focused on the channel of the switching unit 160 of a limited size, so that adjacent wavelength channels Thereby increasing the independence between them.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand.

Accordingly, the true scope of protection of the present invention should be defined by the claims.

50: input port portion 60: output port portion
110: polarized optical part 111: collimated lens
113: birefringence crystal 114: half-wave plate
120: switching lens unit 130a:
130b: Relay lens 131: Extension lens
133: image lens unit 150:
151: prism part 153: grating part
160: switching section 161: switching channel section

Claims (12)

A switching lens unit for crossing an optical beam transmitted from the input / output port array on a switching axis;
A light expanding unit for expanding the beam size of the optical beam output from the switching lens unit in the direction of the dispersion axis;
A splitter for splitting an optical beam having a beam size expanded by the optical expander at different angles on a dispersion axis according to a wavelength component;
An image lens unit for redirecting and focusing the separated wavelength of the optical beam; And
And a switching unit for displacing an angle of the selected wavelength on the switching axis so as to transmit the selected wavelength in the plurality of wavelength channels to the independently selected output port array,
Further comprising a polarization optical section that splits any polarized light transmitted from the input / output port array into two optical beams having the same polarization state and arranges the two separated optical beams on the dispersion axis switch.
delete The method according to claim 1,
Wherein the switching lens unit is a cylindrical lens having a curvature on the switching axis.
The method according to claim 1,
And a collimator lens for collimating an optical beam emitted from the input / output port array on the dispersion axis to the input / output port array side of the switching lens section.
The method according to claim 1,
Wherein the optical expander increases the beam size by expanding the optical beam in the dispersion axis direction by using a telescopic method between two lenses having different focal lengths.
6. The method of claim 5,
Wherein the optical expanding portion comprises at least one or more cylindrical lenses having a curvature on a dispersion axis.
6. The method of claim 5,
Wherein the image lens unit re-enters the optical beam output from the optical expanding unit to function as an optical expansion lens on the dispersion axis.
8. The method of claim 7,
Wherein the image lens unit is used as a part of a relay lens for relaying an intersection of an output part caused by the switching lens unit on the switching axis.
9. The method of claim 8,
When the optical beam is first incident on the image lens unit,
Wherein the image lens unit serves as an optical expanding lens on the dispersion axis and serves as a first relay lens on the switching axis.
9. The method of claim 8,
When an optical beam is incident on the image lens unit from the light splitting unit at a second order,
Wherein the image lens unit serves as an image lens on the dispersion axis and serves as a second relay lens on the switching axis.
9. The method of claim 8,
Wherein the image lens unit functions as an optically expanding lens on the dispersion axis to again enter the optical beam emerging from the optical expanding unit,
When the optical beam is first incident on the image lens unit,
The image lens part serving as a light expanding lens on the dispersion axis, acting as a first relay lens on the switching axis,
When an optical beam is incident on the image lens unit from the light splitting unit at a second order,
Wherein the image lens unit serves as an image lens on the dispersion axis and serves as a second relay lens on the switching axis.
The method according to claim 1,
The switching unit includes:
And a plurality of switching channel units for reflecting the optical beam output from the image lens unit by wavelength.

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