JP2012203112A - Wavelength selecting switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength selecting switch which allows an enclosure to be made thin while securing a thickness of an optical bench.SOLUTION: The wavelength selecting switch includes: at least one input port 10a; a dispersion part 30 for chromatic dispersion of input light made incident from the input port 10a; a light condensing element 40 which condenses light subjected to chromatic dispersion in the dispersion part 30; a deflecting part 50 which deflects light condensed by the light condensing element 40; at least one output port 10c from which the light deflected by the deflecting part 50 is emitted as output light; an optical bench 70 which supports at least the dispersion part 30 and the light condensing element 40; and an enclosure 60 housing and holding the optical bench 70. The optical bench 70 is attached so that its supporting surface 70b supporting the dispersion part 30 and the light condensing element 40 crosses a surface having the largest projection area of the enclosure 60.

Description

  The present invention relates to a wavelength selective switch for optical communication.

  As a conventional wavelength selective switch used for optical communication, for example, one disclosed in Patent Document 1 is known. FIG. 6 is an exploded perspective view showing a schematic configuration of the wavelength selective switch disclosed in Patent Document 1. As shown in FIG. In this wavelength selective switch, various optical components constituting the optical system of the wavelength selective switch are mounted on a plate-shaped optical bench 100. Then, the optical base 100 on which the optical system is mounted is fixed to the bottom of the casing 101, and the upper opening of the casing 101 is covered with the lid 102 so that the casing 101 is hermetically sealed. Yes.

JP 2009-145887

  By the way, the wavelength selective switch needs to compensate for a stable operation in a specified temperature and humidity range. For this purpose, it is important to accurately arrange various optical components constituting the optical system on the optical bench 100. However, if the optical bench 100 is thin at that time, the optical bench 100 is distorted or deformed by the mounting of the optical components, and it becomes difficult to place the optical components with a desired accuracy. Even if the optical components can be arranged with a desired accuracy, if the optical bench 100 is thin, when the optical bench 100 is fixed to the bottom of the housing 101 by, for example, general screw tightening, the optical bench 100 is similarly attached. Distortion and deformation occur, making it difficult to maintain the placement accuracy of the optical components. Therefore, the optical bench 100 needs a certain thickness.

  On the other hand, the wavelength selective switch is required to be thin. Here, in the configuration of FIG. 6, the thickness of the casing 101 is at least the thickness of the optical bench 100, the clearance for avoiding interference between the optical bench 100 and the casing 101, the height of the optical components, and It is necessary to cover the sum of clearances for avoiding interference between the optical component and the lid 102. Therefore, if the optical bench 100 is thick, it is difficult to reduce the thickness of the housing 101.

  Thus, in the conventional wavelength selective switch, there is a trade-off relationship between the thickness of the optical bench 100 and the thinning of the housing 101, and it is difficult to satisfy both.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wavelength selective switch capable of reducing the thickness of the housing while ensuring the thickness of the optical bench.

The invention of the wavelength selective switch according to the present invention that achieves the above object is as follows:
At least one input port;
A dispersion unit that wavelength-disperses input light incident from the input port;
A condensing element that condenses the light wavelength-dispersed by the dispersion unit;
A deflecting unit for deflecting light collected by the light collecting element;
At least one output port for emitting the light deflected by the deflecting unit as output light;
An optical bench that supports at least the dispersion section and the light collecting element;
A housing for accommodating and holding the optical bench,
The optical bench is attached so that a support surface that supports the dispersion unit and the light condensing element intersects a surface having the largest projected area of the housing.
It is characterized by this.

The input port and the output port are arranged in a straight line,
The deflection unit is supported by a support unit protruding from the support surface of the optical bench between the input port and the output port and the light collecting element,
It is preferable that a light transmission part that transmits the input light and the output light is formed in the support part.

A primary condensing lens that forms a primary condensing point between the input port and the output port and the condensing element;
The support part is disposed so that the light transmission part is located at or near the primary condensing point,
The dispersion unit, the condensing element, and the deflecting unit are:
The input light from the input port is dispersed by the dispersion unit through the primary condenser lens and the condenser element, and the dispersed light is deflected by the deflection unit through the condenser element, It is preferable that the light is emitted as the output light from the output port via the dispersion unit and the light condensing element.

  ADVANTAGE OF THE INVENTION According to this invention, the wavelength selective switch which can make a housing | casing thin can be provided, ensuring the thickness of an optical stand.

It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 1st Embodiment of this invention seeing from the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 1st Embodiment of this invention seeing from the direction orthogonal to the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the modification of the optical baseplate of the wavelength selective switch which concerns on 1st Embodiment. It is a figure which shows the other modification of the optical baseplate of the wavelength selective switch which concerns on 1st Embodiment. It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 2nd Embodiment of this invention seeing from the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 2nd Embodiment of this invention seeing from the direction orthogonal to the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 3rd Embodiment of this invention seeing from the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the structure of the principal part of the wavelength selective switch which concerns on 3rd Embodiment of this invention seeing from the direction orthogonal to the wavelength dispersion direction by a dispersion | distribution part. It is a figure which shows the modification of 3rd Embodiment. It is a disassembled perspective view which shows schematic structure of the conventional wavelength selective switch.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1A and 1B are diagrams schematically showing a configuration of a main part of the wavelength selective switch according to the first embodiment of the present invention. 1A is a diagram of the wavelength selective switch as viewed from the wavelength dispersion direction by the dispersion unit, and FIG. 1B is a diagram of the wavelength selective switch as viewed from the direction orthogonal to the wavelength dispersion direction by the dispersion unit. In the following description, for convenience, FIG. 1A is the front side, and FIG. 1B is the plane side.

  This wavelength selective switch includes one input port 10a, four output ports 10b-10e, a microlens array 20, a dispersion unit 30, a condensing lens 40 that is a condensing element, a deflecting unit 50, and a housing 60. 1A and 1B show the internal configuration of the housing 60, the front plate 60a of the housing 60 is removed in FIG. 1A, and the upper surface plate 60b of the housing 60 is removed in FIG. 1B. Further, in FIGS. 1A and 1B, the chromatic dispersion direction by the dispersion unit 30 is the X direction, and the directions perpendicular to the surface where the dispersed light is spatially spread by the chromatic dispersion of the dispersion unit 30 are the Y direction, the X direction, and the Y direction. The direction orthogonal to the Z direction is taken as the Z direction. In the actual optical path of the wavelength selective switch, when a deflecting member (not shown) such as a mirror or a prism is arranged to bend the optical path, the explanation of the X direction, the Y direction, and the Z direction is as described above. It is assumed that a virtual optical system without any deflecting member is used.

  The input port 10a and the output ports 10b-10e are arranged linearly in the Y direction. Hereinafter, for convenience of description, the input port 10a and the output ports 10b-10e are collectively referred to as the input / output port 10 as appropriate. Each input / output port 10 holds an end portion of an optical fiber. The optical fiber is not shown for the sake of clarity. The microlens array 20 includes spherical or aspherical microlenses 21a-21e corresponding to the input / output ports 10.

  The wavelength division multiplexed optical signal (input light) emitted from the input port 10 a is converted into parallel light by the corresponding microlens 21 a of the microlens array 20 and is incident on the dispersion unit 30.

  The dispersion unit 30 includes a dispersion element 31 made of, for example, a transmissive grating, and disperses input light from the input port 10a into optical signals for each wavelength. FIG. 1B illustrates a case where the dispersion unit 30 can disperse input light into optical signals for each of five wavelengths. In the present embodiment, only five wavelengths to be dispersed are illustrated, but the number is not limited to this number.

  The condensing lens 40 is arranged so that the front focal position thereof substantially coincides with the dispersion base point of the dispersion element 31, and condenses the optical signal wavelength-dispersed by the dispersion unit 30 on the deflection unit 50. Here, when the input light is wavelength division multiplexed with a plurality of discrete wavelengths, the wavelength-dispersed optical signal is condensed on the deflecting unit 50 for each wavelength and condensed. In addition, it is preferable that the plurality of optical signals collected by the condenser lens 40 enter the deflection unit 50 substantially perpendicularly when viewed from a direction perpendicular to the wavelength dispersion direction.

  The deflecting unit 50 includes a plurality of deflecting elements arranged linearly in the wavelength dispersion direction of the dispersing unit 30. In the present embodiment, the deflecting unit 50 is illustrated as including five deflecting elements 51a to 51e, but is not limited to this number. The deflection elements 51a to 51e correspond to the five wavelengths dispersed by the dispersion unit 30, and are configured to be independently driven. Thereby, the optical signal for each wavelength incident on the deflecting unit 50 is deflected. The deflection unit 50 including such array-shaped deflection elements 51a to 51e is configured using, for example, a MEMS (Micro Electro Mechanical Systems) mirror, a liquid crystal element, an optical crystal, or the like.

  The optical signals for each wavelength deflected by the deflecting unit 50 enter the desired output ports 10b-10e as output light through the condenser lens 40 and the dispersing unit 30, respectively. FIG. 1A illustrates a case where output light is incident on the output port 10c.

  The housing 60 includes a front plate 60a, a top plate 60b, left and right side plates 60c and 60d, a back plate 60e, and a bottom plate 60f. The area of the front plate 60a, the left and right side plates 60c and 60d, and the back plate 60e ( The area (projected area) of the top plate 60b and the bottom plate 60f is larger than the projected area). In addition, the name of each surface of the housing | casing 60 is a thing for convenience when FIG. 1A is made into the front side. 1A is a view showing the front plate 60a removed, and FIG. 1B is a view showing the top plate 60b removed. In the wavelength selective switch according to the present embodiment, an optical stage which is an optical stage in which the input / output port 10, the dispersion unit 30, the condenser lens 40, and the deflection unit 50 are supported on the back plate 60 e of the housing 60. A base plate 70 is attached.

  The optical base plate 70 is formed of, for example, metal or glass having a relatively low linear expansion coefficient, and is attached to a plurality of (two in the drawing) support bases 61 provided on the back plate 60e by screws 62. In other words, the optical base plate 70 is attached to the back plate 60e so that support surfaces 70a, 70b, and 70c, which will be described later, intersect with the top plate 60b and the bottom plate 60f having the largest projected area, and preferably orthogonal to each other. It has been. In the present embodiment, the screws 62 are used to easily fasten the optical base plate 70 and the back plate 60e of the housing 60, but the present invention is not limited to this, and it may be fastened using an adhesive. Further, the number of screws 62 is not limited.

  Here, the input / output port 10 is fixed to the input / output unit substrate 12 by bonding or the like via the port support substrate 11. The microlens array 20 is fixed to the input / output unit substrate 12 by bonding or the like so that the microlenses 21 a to 21 e correspond to the ports 10 a to 10 e of the input / output port 10. The input / output unit substrate 12 to which the input / output port 10 and the microlens array 20 are fixed is fixed to the support surface 70a of the optical base plate 70 by adhesion or the like. That is, the input / output port 10 and the microlens array 20 are unitized and supported by the optical base plate 70. In the present embodiment, in consideration of ease of assembly, the input / output port 10 and the microlens array 20 are unitized using the port support base 11 and the unit base 12 and supported by the optical base plate. Without using the port support base 11 and the unit base 12, the optical base plate may be directly supported.

  Further, the dispersion element 31 constituting the dispersion unit 30 is supported by the support surface 70 b of the optical base plate 70. The dispersive element 31 is fixed to the support surface 70b of the optical base plate 70 by adhesion or the like. The condenser lens 40 and the deflecting unit 50 are respectively fixed to the support surface 70c of the optical base plate 70 by adhesion or the like. The flexible substrate 52 connected to the deflection unit 50 is led out to the outside through a takeout port 60g formed in the bottom plate 60f. In order to maintain the sealing performance inside the housing 60, the gap between the outlet 60 g and the flexible substrate 52 is filled with a sealing agent 63.

  The optical base plate 70 can be divided into a plurality of members as shown in FIGS. 2A and 2B. At that time, the plurality of members can be connected with an adhesive as shown in FIG. 2A, connected with a screw 65 as shown in FIG. 2B, or connected by various connecting methods.

  As shown in FIG. 1B, the optical base plate 70 is located with respect to the support surface 70c of the dispersion unit 30, the condensing lens 40, and the deflection unit 50 so that the optical axis of the condensing lens 40 and the support surface 70c are substantially parallel. Thus, the support surface 70a of the input / output unit substrate 12 is formed in an inclined bent shape. Therefore, the back plate 60 e of the housing 60 is also bent according to the bent shape of the optical base plate 70. However, the back plate 60e can be formed in a rectangular box shape as a whole by making the support base 61 longer and having a flat shape parallel to the front plate 60a. In FIG. 1A, in order to clarify the drawing, input light from the input port 10a is vertically incident on the dispersion unit 30, and output light is emitted from the dispersion unit 30 vertically, so that the input / output port 10, the microlens array 20, the dispersion | distribution part 30, the condensing lens 40, and the deflection | deviation part 50 are illustrated so that it may rank with a linear form in a Z direction.

  As described above, in the present embodiment, the optical base plate 70 is attached to the back plate 60e so that the support surfaces 70a, 70b, and 70c intersect the top plate 60b and the bottom plate 60f having the largest projected area. ing. Therefore, since the required thickness of the optical base plate 70 can be easily ensured without increasing the height (thickness) of the housing 60, the housing 60 can be easily reduced in thickness. .

  Although FIG. 1A illustrates one input port 10a and four output ports 10b-10e, the input port 10a may be an output port and the output port 10b-10e may be an input port. Also, the numbers of input ports and output ports are set as appropriate without being limited to the examples. In other words, as described above, the wavelength selective switch according to the present invention is not limited to the case where the wavelength division multiplexed input light is dispersed and outputted for each wavelength, and a plurality of input lights for each wavelength are multiplexed and outputted. May be used as well. In addition, the input port and the output port are not limited to being arranged in an array at one place, and the input port and the output port may be arranged at different places by being spatially separated.

(Second Embodiment)
FIG. 3A and FIG. 3B are diagrams schematically showing a configuration of a main part of the wavelength selective switch according to the second embodiment of the present invention. 3A and FIG. 3B correspond to FIG. 1A and FIG. 1B, and the same reference numerals are given to the same components as those shown in FIG. 1A and FIG. To do.

  In the wavelength selective switch according to the present embodiment, in the configuration shown in FIGS. 1A and 1B, a bending mirror 80 is disposed in the optical path between the condenser lens 40 and the deflecting unit 50, and the optical path is changed to the bottom plate 60f. It is bent approximately 90 degrees to the side. The bending mirror 80 is fixed to the support surface 70c of the optical base plate 70 by adhesion or the like. In addition, the deflecting unit 50 is optically rotated in a posture rotated by approximately 90 degrees with respect to the posture in the first embodiment so that the dispersed light reflected by the bending mirror 80 is incident on the deflecting elements 51a-51e. It is fixed to the support surface 70c of the base plate 70 by adhesion or the like. That is, the deflection unit 50 is supported by the optical base plate 70 so that the arrangement direction of the deflection elements 51a to 51e is substantially parallel to the bottom plate 60f. Further, the flexible substrate 52 of the deflection unit 50 is led out to the outside through the takeout port 60h formed in the side plate 60d. In order to maintain the sealing performance inside the housing 60, the gap between the outlet 60 h and the flexible substrate 52 is filled with a sealing agent 63.

  As described above, in this embodiment, in the configuration of the first embodiment, the deflecting unit 50 is disposed on the optical base plate 70 so that the arrangement direction of the deflecting elements 51a to 51e of the deflecting unit 50 is substantially parallel to the bottom plate 60f. I support it. Accordingly, the size of the deflecting unit 50 in the arrangement direction (X direction) of the deflecting elements 51a-51e and the Z direction orthogonal thereto is not limited, and in addition to the effect of the first embodiment, the number of wavelength divisions, that is, the number of ports Can be easily dealt with.

(Third embodiment)
FIG. 4A and FIG. 4B are diagrams schematically illustrating a configuration of a main part of the wavelength selective switch according to the third embodiment of the present invention. 4A and 4B correspond to FIGS. 1A and 1B, but FIG. 4A shows the optical system of FIG. 4B in an expanded state. In the following description, the same reference numerals are assigned to components having the same functions as those shown in FIGS. 1A and 1B, and detailed description thereof is omitted.

  In the wavelength selective switch according to the present embodiment, a wavelength division multiplexed optical signal (input light) emitted from the input port 10a is converted into parallel light by the corresponding microlens 21a, and then the primary condenser lens 41. Thus, the light enters the condenser lens 40 through the condensing point F.

  The condensing lens 40 is disposed so that its front focal position is located in the vicinity of the front and rear of the condensing point F of the input light by the primary condensing lens 41, and the input light from the input port 10a that enters through the condensing point F. Is incident on the dispersion unit 30.

  The dispersion unit 30 includes a dispersion element 31 made of a transmissive grating and a folding mirror 33 that is a reflection element, and reflects light dispersed by the dispersion element 31 by the folding mirror 33 so as to be incident on the dispersion element 31 again. have. The dispersive element 31 is disposed so that the dispersive base point is located in the vicinity of the rear focal position of the condenser lens 40.

  The light emitted after being wavelength-dispersed by the dispersion unit 30 is collected by the condenser lens 40, is deflected by approximately 90 degrees by the reflecting prism 81, and is incident on the deflection elements 51a-51e corresponding to the wavelength of the deflection unit 50. The Then, the light is deflected independently by each of the deflecting elements 51a to 51e, and passes through the reflecting prism 81, the condensing lens 40, the dispersion unit 30, the condensing lens 40, and the primary condensing lens 41 to the desired output port 10b-10e. Incident as output light. 4A illustrates the case where one of the dispersed lights from the dispersion unit 30 is incident on the output port 10c, and FIG. 4B illustrates the case where the dispersion unit 30 disperses the light into three wavelengths. .

  In the above configuration, the input / output port 10 and the microlens array 20 are unitized on the input / output unit substrate 12 as in the first embodiment, and supported by one end of the support surface 70d of the optical base plate 70. The primary condensing lens 41 and the condensing lens 40 are fixed to the support surface 70d of the optical base plate 70 by adhesion or the like so that each optical axis is substantially parallel to the support surface 70d.

  The dispersion element 31 constituting the dispersion part 30 is supported by the other end part of the support surface 70d of the optical base plate 70 on the support surface 70e at the tip part extending substantially perpendicularly from the support surface 70c. Further, the folding mirror 33 is supported by the support surface 70 d of the optical base plate 70. The dispersion element 31 is fixed to the support surface 70d of the optical base plate 70 by adhesion or the like. Similarly, the folding mirror 33 is fixed to the support surface 70d by adhesion or the like.

  The reflecting prism 81 and the deflecting unit 50 are respectively bonded to the support surface 71a of the support unit 71 formed so as to protrude substantially perpendicularly from the support surface 70d of the optical base plate 70 between the primary condensing lens 41 and the condensing lens 40. Etc., and is supported by the optical base plate 70. The support portion 71 is formed on the optical base plate 70 so as to cross the primary condensing point by the primary condensing lens 41 or an optical path near the primary condensing point 41, and in a portion through which input light and output light to the input / output port 10 are transmitted. Has an opening 71b as a light transmitting portion.

  As in the first embodiment, the optical base plate 70 is preferably orthogonal to the upper surface plate 60b and the bottom surface plate 60f having the largest projected area so that the support surfaces 70d, 70e, 71a intersect. In addition, the screw 62 is attached to a support base 61 provided on the back plate 60e. 4A shows an optical element on which input light and output light act between the input / output port 10 and the reflecting prism 81 in a linear form in the Z direction.

  According to this embodiment, since the optical base plate 70 is attached to the back plate 60e, the required thickness of the optical base plate 70 is increased without increasing the height (thickness) of the housing 60, as in the above-described embodiment. Therefore, it is possible to easily reduce the thickness of the housing 60.

  Further, in the present embodiment, the input light from the input port 10a is wavelength-dispersed by the dispersion unit 30 having the Littman-Metcalf structure through the primary condenser lens 41 and the condenser lens 40, and then through the reflecting prism 81. It is deflected by the deflecting unit 50. The deflected light is output from the output port 10 c via the reflecting prism 81, the dispersion unit 30, the condenser lens 40, and the primary condenser lens 41. In addition, since the support portion 71 that supports the reflecting prism 81 and the deflecting portion 50 is disposed at a position crossing the primary condensing point by the primary condensing lens 41 or the optical path in the vicinity thereof, it transmits the input light and the output light. The opening 71b can be reduced, and as a result, the support 71 itself can be reduced. Therefore, while having a compact configuration as a whole, the spatial spread width of the dispersed light in the dispersed optical path can be increased, and the S / N of the output light can be improved and the crosstalk can be reduced.

  Further, since the deflection unit 50 is supported by the support unit 71 so that the arrangement direction of the deflection elements 51a-51e is substantially parallel to the bottom plate 60f, the number of wavelength divisions, that is, the port, is the same as in the second embodiment. The increase in the number can be easily dealt with.

  In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible. For example, in the third embodiment, the reflecting prism 81 may be omitted, and the deflecting unit 50 may be supported by the supporting unit 71 so that the light wavelength-dispersed by the dispersing unit 30 is directly deflected by the deflecting unit 50. it can. Further, the opening 71b formed in the support portion 71 may have various hole shapes, or may have a notch shape in which the upper surface plate 60b side or the bottom surface plate 60f side of the housing 60 is opened.

  Moreover, since the opening part 71b should just permeate | transmit input light and output light, the whole support part 71 can also be formed with transparent members, such as glass. Alternatively, as shown in FIG. 4, an input / output unit substrate in which a block-like column 72 is formed at one end of the optical base plate 70 and the input / output port 10 and the microlens array 20 are unitized on the front support surface 72a. 12 and the reflecting prism 81 and the deflecting unit 50 (not shown) or only the deflecting unit 50 are attached to the side support surface 72b, and the optical paths of the input light and the output light can be set away from the support column 72. .

  Further, since the dispersion unit 30 and the condensing lens 40 have a relatively large projected area of parts compared to other optical parts and the layout of the parts is restricted, at least the dispersal unit 30 and the condensing lens 40 are arranged in the back. The optical base plate 70 attached to the face plate 60e may be supported, and other optical components may be configured to be supported by another optical base plate attached to the bottom plate 60f, for example.

  Moreover, the condensing lens 40 should just have a condensing effect | action, A condensing mirror, a diffraction type condensing element, etc. can be used. Moreover, in each embodiment, the microlens array 20 does not necessarily need to be arranged. Further, the dispersion section is not limited to a transmission type dispersion element or a Littman-Metcalf structure, and a reflection type diffraction grating, Grism, super prism, or the like can also be used.

10a Input port 10b-10e Output port 30 Dispersion part 31 Dispersion element 33 Folding mirror 40 Condensing lens 41 Primary condensing lens 50 Deflection part 51a-51e Deflection element 60 Housing 60b Top plate 60c, 60d Side plate 60e Back plate 60f Bottom Face plate 61 Support base 62 Screw
63 Sealant 65 Screw 70 Optical base plate 70a, 70b, 70c, 70d, 70e Support surface 71 Support portion 71a Support surface 71b Opening portion 80 Bending mirror 81 Reflective prism

Claims (3)

At least one input port;
A dispersion unit that wavelength-disperses input light incident from the input port;
A condensing element that condenses the light wavelength-dispersed by the dispersion unit;
A deflecting unit for deflecting light collected by the light collecting element;
At least one output port for emitting the light deflected by the deflecting unit as output light;
An optical bench that supports at least the dispersion section and the light collecting element;
A housing for accommodating and holding the optical bench,
The optical bench is attached so that a support surface that supports the dispersion unit and the light condensing element intersects a surface having the largest projected area of the housing.
A wavelength selective switch characterized by that. The input port and the output port are arranged in a straight line,
The deflection unit is supported by a support unit protruding from the support surface of the optical bench between the input port and the output port and the light collecting element,
The support portion is formed with a light transmission portion that transmits the input light and the output light.
The wavelength selective switch according to claim 1. A primary condensing lens that forms a primary condensing point between the input port and the output port and the condensing element;
The support part is disposed so that the light transmission part is located at or near the primary condensing point,
The dispersion unit, the condensing element, and the deflecting unit are:
The input light from the input port is dispersed by the dispersion unit through the primary condenser lens and the condenser element, and the dispersed light is deflected by the deflection unit through the condenser element, Arranged so as to be emitted as the output light from the output port through the dispersion unit and the light collecting element,
The wavelength selective switch according to claim 2.

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