JP2012168287A - Wavelength selection switch and optical unit for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength selection switch and an optical unit for the same capable of easily replacing a deflection section.SOLUTION: An optical unit for a wavelength selection switch 125 comprises: at least one input port 109; a dispersion section 113 to perform wavelength dispersion of incoming input light from the input port 109; a focusing element 115 to focus light dispersed by the dispersion section 113; at least one output port 110; and a housing 101 to seal the input port 109, the dispersion section 113, the focusing element 115 and the output port 110. The housing 101 has a transparent section which is optically transparent and arranged at a position where the light focused by the focusing element 115 is incident thereon.

Description

  The present invention relates to a wavelength selective switch and an optical unit for wavelength selective switch.

  In recent years, WDM (Wavelength Division Multiplexing) technology has been used in optical fiber networks that show a wide range of service areas in order to enable a large amount of data communication, and wavelength multiplexed light is transmitted to each optical fiber. Is being transmitted. In such an optical switch for branching or coupling optical signals, a wavelength selective switch capable of switching for each multiplexed wavelength is required.

  The wavelength selective switch has an input port for inputting an optical signal, a collimator lens for collimating a light beam emitted from the input port, a dispersion unit (diffraction grating) for wavelength-dispersing the collimated light, and condensing the dispersed light beam. A condensing lens, a deflecting unit that changes the traveling direction of each light beam so that the dispersed and condensed light beams of each wavelength enter an arbitrary output port, and the like are provided. Contrary to the above example, there is also a wavelength selective switch that disperses the signal light from the input port for inputting a plurality of optical signals to each multiplexed wavelength and selectively couples it to one output port. Necessary.

  Since these wavelength selective switches are the main devices of optical communication networks that require high reliability and are required to operate stably over a long period of time, the components of wavelength selective switches are conventionally incorporated in a housing. Therefore, it has been proposed that hermetic sealing (hermetic sealing) is performed (for example, Patent Document 1).

JP 2009-145887

  However, if all the components of the wavelength selective switch are sealed in one case, the life of each component will be different, but if any one of them fails, it must be replaced on a case-by-case basis. . Among the component parts, the deflection unit, which is the only movable part, is more likely to fail than other component parts. For this reason, there are many possibilities that a failure occurs in the wavelength selective switch due to the deflection unit. In such a case, it is conceivable that the deflection unit is replaced and repaired. However, when the deflection unit is in the hermetically sealed housing, or when the deflection unit is a part of the hermetic sealed housing, removing the deflection unit opens the hermetic seal of the optical system. As a result, problems such as adhesion of dust to the optical components and exposure to moisture occur, so that it is difficult to remove and replace the deflecting unit. Therefore, the failed wavelength selective switch is replaced on a case-by-case basis. It may be possible to replace the deflection unit in a room with a very high degree of cleanliness and humidity controlled, but it is very difficult to work without attaching dust and dirt generated by removing the deflection unit to the optical system. It is.

  Accordingly, an object of the present invention, which has been made in view of the above-described problems of the prior art, is to provide a wavelength selective switch and an optical unit for wavelength selective switch that can easily replace a deflection unit.

In order to solve the above-described problems, the optical unit for wavelength selective switch according to the first aspect is:
At least one input port;
A dispersion unit for wavelength-dispersing the input light input from the input port;
A condensing element that condenses the light dispersed by the dispersion unit;
At least one output port;
A housing for sealing the input port, the dispersion unit, the light collecting element, and the output port;
The case is an optical unit for a wavelength selective switch in which an optically transparent transparent portion is formed at a position where light condensed by the light collecting element is incident.

  Moreover, it is preferable that the said transparent part inclines with respect to the light beam from the said condensing element.

  Moreover, it is preferable that the said transparent part is a sealing window formed in the said housing | casing.

  Moreover, it is preferable that the said transparent part is a plate formed in the said housing | casing, and the said input port, the said dispersion | distribution part, the said condensing element, and the said output port are arrange | positioned on the said plate.

  The plate is preferably made of quartz.

  The wavelength selective switch optical unit preferably includes an attachment member that is provided outside the housing and attaches a deflection unit that deflects light.

The wavelength selective switch according to the second aspect is
The wavelength selective switch optical unit;
A deflection unit that is attached to the outside of the housing and deflects the light collected by the light collecting element toward the light collecting element;
Is a wavelength selective switch.

The wavelength selective switch according to the third aspect is
The wavelength selective switch optical unit provided on the outside of the housing and provided with an attachment member for attaching a deflection unit for deflecting light; and
The deflection unit is a wavelength selection switch that is attached to the outside of the housing and deflects the light collected by the condensing element toward the condensing element.

  The deflecting unit is configured by mounting an element having a light deflecting function on a package in which a part through which a light beam passes is configured by a transparent member, and the transparent member of the package is mounted on the transparent unit of the casing. It is preferable that it is attached.

  Moreover, it is preferable that the said transparent part of the said housing | casing and the transparent member of the said deflection | deviation part are attached with the optically transparent adhesive agent in use wavelength.

  Moreover, it is preferable that the said deflection | deviation part is screwed by the said housing | casing.

  According to the wavelength selective switch and the wavelength selective switch optical unit according to the present invention configured as described above, the deflection unit is attached to the outside of the housing. As a result, the user can easily replace the deflecting unit while maintaining the hermetic seal of the optical member.

FIG. 1 is a schematic configuration diagram of a wavelength selective switch according to the first embodiment of the present invention. FIG. 2 is a configuration diagram of an optical unit for wavelength selective switch of the wavelength selective switch shown in FIG. FIG. 3 is a modification of the wavelength selective switch shown in FIG. FIG. 4 is a modification of the wavelength selective switch shown in FIG. FIG. 5 is a schematic configuration diagram of a wavelength selective switch according to the second embodiment of the present invention. FIG. 6 is a configuration diagram of an optical unit for wavelength selective switch of the wavelength selective switch shown in FIG. FIG. 7 is a modification of the wavelength selective switch shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a wavelength selective switch according to the first embodiment of the present invention. The wavelength selective switch 11 according to the present embodiment includes a housing 101, an optical system 103 assembled in the housing 101, and a deflecting unit 105 that is detachably attached to the outside of the housing 101. .

  The housing 101 has an optically transparent sealing window 107 provided at an attachment portion of the deflecting unit 105, and has a sealed structure. The sealing window 107 has an optical surface 127. The sealing window 107 is made of, for example, glass, and the portion other than the sealing window 107 of the housing 101 is made of, for example, metal. And the whole housing | casing 101 is hermetic sealed, for example, and the outstanding airtightness is implement | achieved.

  The optical system 103 includes at least one input port 109, at least one output port 110, a microlens array 111, a dispersion unit 113, a condensing element 115, and a mirror 117. The components of the optical system 103 are mounted on the plate 119, and the plate 119 is made of, for example, metal or quartz. The plate 119 is more preferably composed of a material having a small linear expansion capable of suppressing the relative displacement of the optical component at high and low temperatures. In FIG. 1, three ports including the input port 109 and the output port 110 are illustrated, but the number of ports is not limited to three.

  The input port 109 is for inputting wavelength-multiplexed light to the wavelength selective switch 11. Further, the output port 110 is for allowing light incident from the input port 109 to be emitted as signal light after the path is switched for each wavelength. The input port 109 and the output port 110 are formed by optical fibers or optical waveguides. In the present application, the vicinity of the tip of the optical fiber or the optical waveguide is described as the input port 109 or the output port 110 in particular. A port array can be formed by combining at least one input port 109 and at least one output port 110. Depending on the combination, a port array having a single port input port and a multi-port output port, a multi-port A port array having an input port and a single output port and a port array having a multi-port input port and a multi-port output port can be realized. In FIG. 1, only the input port 109 or the output port 110 in the vicinity of the tip of the optical fiber or the optical waveguide is illustrated. Actually, an optical fiber or an optical waveguide extends from the illustrated input port 109 and output port 110, respectively. Then, the optical fiber or the optical waveguide is extended to the outside of the housing 101 as a fiber array or an optical waveguide. Here, the through-hole for passing the fiber array formed in the housing 101 and the fiber array are arranged without a gap. For this reason, the inside of the housing 101 is kept sealed despite the fiber array extending outside the housing.

  In the microlens array 111, microlenses that are paired with the input port 109 and the output port 110 are arranged in an array. The microlens array 111 converts the input light incident from the input port 109 into a parallel light beam and converges the light returned from the light deflecting unit 105 to the output port 110.

  The dispersion unit 113 is for dispersing the light collimated by the microlens array 111 for each wavelength, and is composed of, for example, a transmission type dispersion element (grating). Note that a dispersion element having a Littman-Metcalf type structure may be used as the dispersion unit 113. In this embodiment, a transmissive dispersion element is used. However, the present invention is not limited to this, and a reflective diffraction grating, Grism, super prism, or the like can also be used.

  The condensing element 115 is, for example, a condensing lens, and condenses the light (dispersed light) dispersed for each wavelength by the dispersion unit 113 at a predetermined position for each wavelength on the deflection unit 105. As the condensing element 115, a condensing mirror, a diffractive condensing element, or the like can also be used.

  The mirror 117 reflects the light from the condensing element 115 and guides it to the deflecting unit 105 through the plate 119 and the sealing window 107. Therefore, when the plate 119 is made of metal, the plate 119 is provided with a hole for forming an optical path between the mirror 117 and the sealing window 107. In the case where the plate 119 is formed of an optically transparent member, for example, quartz, it can be omitted to form an optical path hole in the plate 119. In addition, since the deflection | deviation part 105 is provided in the advancing direction of the light from the condensing element 115, the mirror 117 is needed, but this embodiment is not necessarily limited to this aspect. When the deflecting unit 105 is provided in the traveling direction of the light from the condensing element 115, the mirror 117 can be omitted.

  The deflecting unit 105 deflects the optical path of the dispersed light so as to make each dispersed light reflected by the mirror 117 enter a predetermined output port 110. In this embodiment, the light from the optical system 103 passes through the sealing window 107 and enters the deflecting unit 105, the direction of which is deflected by the deflecting unit 105, and returns to the optical system 103 again. That is, the optical path between the optical system 103 and the deflecting unit 105 is formed through the sealing window 107. The light returning to the optical system 103 passes through the mirror 117, the condensing element 115, the dispersion unit 113, and the microlens array 111 in order, and enters the output port 110 corresponding to the wavelength.

  The deflecting unit 105 is, for example, a MEMS (Micro Electro Mechanical Systems) mirror array or a LOCS (Liquid crystal on silicon) that is a reflective liquid crystal display panel. When the deflection unit 105 is a MEMS mirror array, the deflection unit 105 includes a plurality of micromirrors corresponding to wavelengths arranged in an array. Each micromirror is driven by power supply from the cable 121, thereby changing the inclination of the mirror itself and changing the traveling direction of light for each wavelength.

  The deflection unit 105 is attached to the outside of the housing 101. For example, the deflection unit 105 is bonded and fixed to an attachment member 123 attached to the housing 101 or is fixed by a screw. At this time, the deflection unit 105 may be directly attached to the housing 101 without the fixing unit 123.

  As described above, in this embodiment, the deflecting unit 105 is attached to the outside of the housing 101, and the optical path between the optical system 103 and the deflecting unit 105 in the housing 101 is an optically transparent sealing window 107. It is formed to pass through. That is, the deflecting unit 105 constituting the wavelength selective switch 11 is located outside the casing 101 and can be removed while keeping the hermetic seal of the casing 101. The deflecting unit 105 can be replaced without considering the damage to the optical system due to moisture and dust. In addition, even when the attachment of the deflecting unit 105 fails, it can be once removed, adjusted and fixed again. Since only the deflection unit 105 can be replaced and adjusted, it is not necessary to discard other components of the wavelength selective switch 11. That is, the wavelength selective switch 11 in this embodiment is excellent in terms of cost and environment.

  Furthermore, since the deflection unit 105 can be fixed to the mounting member 123 by screwing, the user of the wavelength selective switch 11 can easily remove and replace the deflection unit 105.

  Even if the attachment member 123 is independent of the casing 101, or as shown in FIG. 2, the wavelength selection switch optical unit 125 is attached to the casing 101 in advance and together with the casing 101 including the optical system 103. May be formed.

  In addition, as shown in FIG. 3, the deflection unit 105 can be attached to the sealing window 107 without using the attachment member 123. Since the deflecting unit 105 is often sealed with a cover glass or the like for protecting a device for deflecting light from dust or the like, the sealing glass and the casing 101 are hermetically sealed. The window 107 can be fixed to the housing 101 by joining with an optically transparent adhesive.

  In this embodiment, referring to FIG. 1, the optical surface 127 of the sealing window 107 is shown to be perpendicular to the light flux from the optical system 103. It is not necessarily limited to the embodiment. For example, the optical surface 127 can be tilted with respect to the light beam from the optical system 103. When the optical surface 127 is arranged perpendicular to the light flux from the optical system 103, the reflected light from the optical surface 127 passes through the optical path of the light from the input port 109 to the sealing window 107 in the reverse direction. Alternatively, the light may enter the output port 110 as stray light. In such a case, the SN ratio (signal-to-noise ratio) of the optical signal is reduced and the crosstalk is increased. Therefore, by tilting the optical surface 127 with respect to the light beam from the optical system 103, the direction of the reflected light can be changed and the reflected light can be prevented from entering the input port 109 or the output port 110.

  In the above-described embodiment, the configuration is such that the optical system 103 is fixed to the plate 119. However, the present invention is not limited to this, and a modification as shown in FIG. 4 is also conceivable. In the configuration shown in FIG. 4, the optical system 103 is fixed on the housing 101 or the sealing window 107. Other configurations are the same as those in the example of FIG. With such a configuration, the plate 119 can be omitted, and cost reduction can be expected by reducing the number of parts. In FIG. 4, the deflection unit 105 is attached via the attachment member 123, but it may be attached directly to the sealing window 107 as shown in FIG. 3.

(Second Embodiment)
FIG. 5 is a schematic configuration diagram of a wavelength selective switch according to the second embodiment of the present invention. The wavelength selective switch 21 according to the present embodiment includes a housing 201, an optical system 203 assembled in the housing 201, and a deflecting unit 205. The optical system 203 (including at least one input port 209, at least one output port 210, a microlens array 211, a dispersion unit 213, a condensing element 215, and a mirror 217) and a deflection unit 205 are illustrated in FIG. One optical system 103 (including at least one input port 109, at least one output port 110, a microlens array 111, a dispersion unit 113, a condensing element 115, and a mirror 117), and a deflecting unit 105. Since it has the same function, description is abbreviate | omitted.

  A part of the housing 201 is an optically transparent plate 219 and seals the optical system 203 assembled on the plate. The plate 219 is made of, for example, quartz.

  Input light incident from the input port 209 passes through the microlens array 211, the dispersion unit 213, and the light collecting element 215, and is reflected by the mirror 217. The light reflected by the mirror 217 passes through the plate 219 and is guided to the deflecting unit 205, the direction is deflected by the deflecting unit 205, and returns to the mirror 217 (optical system 203) again. That is, the optical path between the optical system 203 and the deflecting unit 205 is formed through the plate 219. The light that has returned to the optical system 203 is emitted as output light through the mirror 217, the condensing element 215, the dispersion unit 213, the mirror array 211, and the output port 210 in order.

  The plate 219 can be provided with an antireflection film (not shown) in a region where an optical path between the optical system 203 and the deflecting unit 205 passes. As a result, the amount of unnecessary light reflected by the plate 219 entering the input port 209 and the output port 210 via the mirror 217 of the optical system 203 is reduced, thereby preventing problems of crosstalk and S / N degradation. Can do.

  Similar to the first embodiment, the deflection unit 205 is detachably attached to the outside of the housing 201. For example, the deflecting unit 205 is adhesively fixed or screwed to an attachment member 223 attached to the outside of the plate 219. At this time, the deflecting unit 205 may be directly attached to the housing 201 without the attaching unit 223.

  As described above, in this embodiment, the deflecting unit 205 is attached to the outside of the housing 201, and the optical path between the optical system 203 and the deflecting unit 205 in the housing 201 is transmitted through the optically transparent plate 219. Is formed. That is, since the deflection unit 205 constituting the wavelength selective switch 21 is located outside the housing 201 and can be removed while keeping the hermetic seal of the housing 201, when the deflection unit 205 fails, The deflecting unit 205 can be replaced without considering the damage to the optical system due to moisture and dust. Therefore, even when the attachment of the deflecting unit 205 has failed, it can be once removed, adjusted and fixed again. Since only the deflecting unit 205 can be replaced and adjusted, it is not necessary to discard other components of the wavelength selective switch 21. That is, the wavelength selective switch 21 in this embodiment is excellent in terms of cost and environment. Furthermore, in order to realize an optical path between the optical system 203 in the casing 201 and the deflecting unit 205 outside the casing 201, a plate 219 for attaching the optical system 203 is effectively used. Therefore, since the installation of the transparent sealing window as described in the first embodiment can be omitted, the wavelength selective switch can be easily manufactured. Further, by using a glass having a small linear expansion such as quartz for the plate 219, it is possible to suppress the relative displacement of the optical components at high temperature and low temperature, and to further improve the reliability.

  Further, when the deflection unit 205 is fixed to the mounting member 223 by screwing, the user of the wavelength selective switch 21 can easily remove the deflection unit 205 and replace it.

  Note that the attachment member 223 is independent of the housing 201 or is attached to the housing 201 in advance as shown in FIG. 6, and the wavelength selective switch optical unit 225 is mounted together with the housing 201 including the optical system 203. It may be formed.

  Further, as shown in FIG. 7, the deflection unit 205 can be attached to the plate 219 without using the attachment member 223. Since the deflecting unit 223 is often sealed with a cover glass or the like for protecting a device for deflecting light from dust or the like, the protective glass and the plate 219 are bonded with an optically transparent adhesive. It can fix to the plate 219 by joining.

  In the present embodiment, referring to FIG. 5, the optical surface 227 of the plate 219 is shown to be perpendicular to the light beam from the optical system 203. It is not limited. For example, the optical path passing portion of the optical surface 227 can be partially tilted with respect to the light beam from the optical system 203 by polishing. When the optical surface 227 is arranged perpendicular to the light beam from the optical system 203, the reflected light from the optical surface 227 passes through the optical path of the light from the input port 209 to the mirror 217 in the reverse direction, or There is a possibility that the light enters the output port 210 as stray light. In such a case, the SN ratio (signal-to-noise ratio) of the optical signal is reduced and the crosstalk is increased. Therefore, by tilting the optical surface 227 with respect to the light beam from the optical system 203, the direction of the reflected light can be changed and the reflected light can be prevented from entering the input port 209 or the output port 210.

  Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention.

  For example, the functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined into one or divided. Is possible.

  In the first and second embodiments of the present invention described above, the optical system includes at least one input port, at least one output port, a microlens array, a dispersion unit, a condensing element, and a mirror. It should be noted that the optical system of the present invention can include additional components. For example, the optical system can include a cylindrical lens, an optical path adjusting plate for adjusting the optical path of light, and the like. The microlens array is not necessarily arranged. If the light beam input from the input port is a parallel light beam, the light beam does not necessarily have to be made parallel by a collimating element such as a microlens array.

11, 21 Wavelength selection switch 101, 201 Case 103, 203 Optical system 105, 205 Deflection unit 107 Sealing window 109, 209 Input port 110, 210 Output port 111, 211 Micro lens array 113, 213 Dispersion unit 115, 215 Collection Optical element 117, 217 Mirror 119, 219 Plate 121, 221 Cable 123, 223 Mounting member 125, 225 Optical unit for wavelength selective switch 127, 227 Optical surface

Claims (11)

At least one input port;
A dispersion unit for wavelength-dispersing the input light input from the input port;
A condensing element that condenses the light dispersed by the dispersion unit;
At least one output port;
A housing for sealing the input port, the dispersion unit, the light collecting element, and the output port;
The optical unit for wavelength selective switches, wherein the casing is formed with an optically transparent transparent portion at a position where light condensed by the light condensing element is incident.   The wavelength selective switch optical unit according to claim 1, wherein the transparent portion is inclined with respect to a light flux from the light collecting element.   The wavelength selective switch optical unit according to claim 1, wherein the transparent portion is a sealing window formed in the housing. The transparent part is a plate formed in the housing,
The wavelength selective switch optical unit according to claim 1, wherein the input port, the dispersion unit, the condensing element, and the output port are arranged on the plate.   The wavelength selective switch optical unit according to claim 4, wherein the plate is made of quartz.   6. The optical unit for wavelength selective switch according to claim 1, further comprising an attachment member that is provided outside the housing and attaches a deflection unit that deflects light. Optical unit for wavelength selective switch according to claim 1;
A deflection unit that is attached to the outside of the housing and deflects the light collected by the light collecting element toward the light collecting element;
Wavelength selective switch with An optical unit for a wavelength selective switch according to claim 6,
A wavelength selective switch that is attached to the outside of the housing and deflects the light collected by the light collecting element toward the light collecting element.   The deflecting unit is configured by mounting an element having a light deflecting function on a package in which a portion through which a light beam passes is configured by a transparent member, and the transparent member of the package is attached to the transparent unit of the casing. The wavelength selective switch according to claim 7 or 8, wherein:   The wavelength selective switch according to claim 9, wherein the transparent portion of the casing and the transparent member of the deflecting portion are attached with an optically transparent adhesive at a used wavelength.   The wavelength selective switch according to claim 7, wherein the deflection unit is screwed to the housing.

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