JP2005234225A - Optical switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical switch in which instantaneous interruption does not occur when switched over and which is compatible to a multichannel. <P>SOLUTION: Eight optical collimators 11 as an input port group at which a light signal is inputted and outputted and eight optical collimators 12 as an output port group are spaced by a predetermined distance and optically coupled via a predetermined optical path. An alternative optical collimator 13 is always located out of the optical path between the optical collimators 11 and 12 and movable in a direction to cross with the optical path. The path of the optical signal is varied by turning a prism 50 having two parallel reflection faces around a rotation axis 46 to insert into and retract from the optical path. Thus, the optical coupling state of the optical collimators are changed, and one of the optical collimators 11 and 12 and the alternative optical collimator 13 are optically switched. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mechanical optical switch that switches connection between input and output of an optical signal.

  In recent years, optical communication using optical fibers has been rapidly developed. In such a communication system, it is common to provide a protection line for switching when an abnormality occurs in the work line, in addition to the work line used for normal communication. As an optical switch used for switching at this time, for example, one having the configuration shown in FIG. 5 is known. The optical switch shown in FIG. 5 includes five incident-side optical collimators 1-1, 1-2, 1-3, 1-4, and 1-5 (hereinafter collectively referred to as the optical collimator 1 depending on the case). ) And five optical collimators 2-1 to 2-2, 2-3, 2-4, and 2-5 (hereinafter referred to as cases) on the emission side that are arranged to face each other and are optically coupled to each other at a predetermined distance. The optical collimator 2 is collectively referred to as a pair and constitutes a 5-channel working line. Here, the optical collimator 1 functions as an incident side port group, and the optical collimator 2 functions as an output side port group. An alternative optical collimator 3 arranged in a direction orthogonal to the direction of the optical collimators 1 and 2 constitutes a protection line. A movable body 4 that moves in the column direction is provided between the optical collimators 1 and 2, and a prism 5 is placed thereon. The prism 5 has a reflecting surface that forms an angle of 45 degrees with respect to the optical paths of the optical collimators 1 and 2 and the outgoing light of the alternative optical collimator 3. The optical collimators 1, 2 and 3 are fixedly arranged on the same plane, and are configured so that the light emitted from the alternative optical collimator 3 can enter the optical collimator 2 by moving the prism 5 to a predetermined position. Yes.

  At normal times, the optical signals emitted from the optical collimator 1 serving as the working line are input to the optically coupled optical collimators 2 that form a pair and transmitted. When an abnormality occurs in the working line for some reason, the moving body 4 is moved and the reflecting surface of the prism 5 is inserted into the optical path between the optical collimators of the channel where the abnormality has occurred. FIG. 5 shows an example in which an abnormality occurs in the optical collimator 1-3 and the prism 5 is inserted in the optical path between the optical collimator 1-3 and the optical collimator 2-3. In this state, the light from the spare optical collimator 3 for the protection line is reflected by the reflecting surface of the prism 5 and enters the optical collimator 1-3. In this way, instead of the optical collimator 1-3 in which an abnormality has occurred, the alternative optical collimator 3 is coupled with the optical collimator 2-3, and switching to the protection line is performed. In addition, an optical switch for switching the connection from a plurality of working line optical fibers to a protection line optical fiber is disclosed in Patent Document 1 below.

JP-A-8-146314

  However, in the optical switch as shown in FIG. 5, the working line optical collimator and the protection line optical collimator are arranged on the same plane. For this reason, when the moving body moves at the time of switching, the prism 5 crosses the optical path of the optical collimator of the normal working line, causing a problem that the normal working line is momentarily interrupted. Further, since the substitute optical collimator 3 for the standby line is fixedly arranged, the distance from the substitute optical collimator 3 to the coupling partner optical collimator varies greatly depending on the working line to be switched. For example, in FIG. 5, the distance from the substitute optical collimator 3 to the foremost optical collimator 2-1 and the distance from the substitute optical collimator 3 to the farthest optical collimator 2-5 are greatly different. If the coupling distance varies depending on the working line to be switched in this way, it is impossible to optimize the coupling conditions for all of the many channels. In such an unoptimized state, a large coupling loss occurs. In particular, as the number of channels on the working line increases, the difference in coupling distance increases and the amount of coupling loss increases, which makes it difficult to increase the number of channels.

  Therefore, the present invention has been made in view of such problems, and an object of the present invention is to provide an optical switch that can cope with an increase in the number of channels without causing an instantaneous interruption at the time of switching. is there.

  In order to solve the above problems, according to an aspect of the present invention, a first port group including a plurality of ports through which optical signals are input and output, and a predetermined optical path separated from each port of the first port group by a predetermined distance. There is provided an optical switch that optically switches at least one port of the second port group consisting of a plurality of ports optically coupled via the switch and a substitute port. This optical switch is located outside the optical path between the first port group and the second port group and moves in a direction crossing the optical path, and an optical signal by being inserted into and removed from the optical path. And a route switching means for performing the switching by changing the route. Here, optically switching means switching of the optical coupling state of each port. For example, a state where the first port of the first port group and the second port of the second port group are optically coupled, and a state where either the first port or the second port and the alternative port are optically coupled And switching. By this switching, the connection between the input and output of the optical signal that has been performed between the first port and the second port is performed between one of the first port and the second port and the substitute port. Can be changed.

  According to such a configuration, when the first port group and the second port group are used as working lines that are normally used and an abnormality occurs in a port of the working line, the optical path is added to the optical path of the port where the abnormality has occurred. A switching means is inserted to change the optical signal path to switch to the substitute port. The optical path switching means can be inserted into and removed from the optical path as necessary, and the substitute port is always located outside the optical path between the input port and the output port. I will not let you decline. In addition, since the replacement port is not fixedly arranged and can be moved between the first port group and the second port group, the coupling distance between the substitution port and the partner port is determined by the number of channels on the working line. Regardless, it can be configured almost constant. Therefore, since the conventional coupling loss problem does not occur, it is possible to provide an optical switch that can cope with multi-channels.

  At that time, the first port group and the second port group may be arranged on the same plane, and the substitute port may not be arranged on the plane. According to such a configuration, the substitute port can always be positioned outside the optical path between the first port group and the second port group. Further, the first port group and the second port group may be arranged in parallel, and the substitute port may be configured to move in the column direction.

  Further, the path switching means may be configured to have two parallel reflecting surfaces and rotate around a predetermined axis. When a light beam incident on one of the two parallel reflecting surfaces is reflected by the reflecting surface and then reflected by the other reflecting surface and emitted, the incident light beam and the outgoing light beam become parallel. Therefore, two parallel paths may be considered as the optical signal path for the path switching means having the above configuration. Further, it can be configured to be inserted into and removed from the optical path by rotating the path switching means around the axis.

  Here, a prism having two parallel reflecting surfaces may be used as the path switching means. It is relatively easy to make such a prism. In this case, if the prism 1 component is arranged at a predetermined position, the two reflecting surfaces are also arranged at the predetermined position at the same time, so that the component can be easily mounted. On the other hand, when two separated mirrors are used instead of the prism, it is necessary to place the two mirror parts at predetermined positions and with high precision so that they are parallel to each other, ensuring the mounting accuracy. Difficult to do.

  Moreover, it is preferable to further include an adjusting unit that specifies the distance between the axis line and the route switching unit and adjusts the movement range of the route switching unit. When the path switching means is moved so as to be inserted into and removed from the optical path, if there is an optical path of an optical signal normally communicating within the movement range, the optical signal line is disconnected, which is not preferable. It is necessary to consider the positional relationship between the moving range of the switching means and the ports through which optical signals are input and output. For this purpose, it is preferable to provide an adjusting means for adjusting the movement range of the route switching means.

  The substitute port may include an optical fiber and collimating means for collimating light from the optical fiber. According to such a configuration, light emitted from the substitute port becomes parallel light, and optical transmission between the substitute port and the outside can be performed by the optical fiber.

  As described above, according to the present invention, an optical signal normally communicating at the time of switching is not interrupted instantaneously, and the coupling distance between the substitute port and the coupling partner port is independent of the number of channels of the working line. Since it can be configured almost constant, it is possible to provide an optical switch that can handle multiple channels.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  An optical switch according to a typical aspect of the present invention includes an input port group including a plurality of ports for inputting / outputting optical signals, an output port group including a plurality of ports for inputting / outputting optical signals, and a substitute port. And a path switching means for optically switching at least one of the input port group and the output port group and the substitute port. The input port group and the output port group are optically coupled via a predetermined optical path at a predetermined distance. The substitute port can move in a direction crossing the optical path, and is always located outside the optical path between the input port group and the output port group during movement and at rest. In order to realize this arrangement, for example, the input port group and the output port group can be arranged on the same plane, and the substitute port can be arranged not to be arranged on this plane. The path switching means performs the switching by changing the path of the optical signal by being inserted into and removed from a predetermined optical path between the input port group and the output port group.

  FIG. 1 is a plan view showing a configuration of an optical switch according to an embodiment of the present invention. This optical switch has an input port group, an output port group, a substitute port, a rail 30, a moving body 40, and a prism 50 as main components. The input port group includes a plurality of ports through which optical signals are input / output. Here, eight optical collimators 11-1, 11-2, 11-3, 11-4, 11-5, 11-6, 11 -7, 11-8 (hereinafter collectively referred to as the optical collimator 11 depending on the case). The output port group includes a plurality of ports through which optical signals are input and output. Here, eight optical collimators 12-1, 12-2, 12-3, 12-4, 12-5, 12-6, 12 -7, 12-8 (hereinafter collectively referred to as the optical collimator 12 depending on the case). The substitute port is composed of a substitute optical collimator 13 through which optical signals are input and output. The optical collimators 11 and 12 function as working line ports that are normally used, and the optical collimator 13 functions as a protection line port that is used when an abnormality occurs. The optical collimators 11, 12, and 13 include an optical fiber and a lens (not shown) as collimating means that is disposed at one end of the optical fiber and collimates light from the optical fiber, and the other end of the optical fiber is a connector. 20 is connected. The optical fiber included in the substitute optical collimator 13 has a sufficient length in consideration of the movement of the substitute optical collimator 13 described later.

  The optical collimator 11 is arranged in parallel on one side of the optical switch. The optical collimator 12 is arranged in parallel on the other side of the optical switch at a predetermined distance from the optical collimator 11. As shown in FIG. 1, the eight optical collimators of the optical collimator 11 are fixedly arranged so as to face the eight optical collimators of the optical collimator 12, respectively. For example, paying attention to the optical collimators 11-1 and 12-1, the two optical collimators have the same optical axis, and a line connecting the input and output ends of the two optical collimators becomes an optical path 15, and the optical collimator 11- The light emitted from 1 is optically coupled through this optical path so as to enter the optical collimator 12-1. Such two optically coupled optical collimators will be referred to herein as optical collimator pairs. Similar to the optical collimators 11-1 and 12-1, the other optical collimators arranged opposite to each other constitute an optical collimator pair. As a whole, these eight optical collimator pairs constitute an 8-channel working line. Here, the optical collimators 11 and 12, that is, the eight optical collimator pairs are all arranged on the same plane. In FIG. 1, only the optical path between the optical collimators 11-1 and 12-1 is illustrated, but the optical path can be considered similarly for other optical collimator pairs.

  A stage 32 having a long side in the column direction of the optical collimator is disposed between the optical collimator 11 and the optical collimator 12. The stage 32 is provided with rails 30 extending from one end of the stage 32 to the other end, extending in the column direction of the optical collimator. A moving body 40 is disposed on the rail 30. The moving body 40 is driven by the moving body driving means 42 and moves using the rail 30 as a moving path. The moving body drive means 42 is, for example, a motor or a motor drive circuit. Here, the moving direction of the moving body 40 is a direction perpendicular to the optical path 15 of the optical collimator. Hereinafter, the direction of the optical path 15 is referred to as an optical path direction, and the direction in which the moving body 40 moves is referred to as a movement direction.

  An alternative optical collimator 13 and a column 44 are placed on the moving body 40. The partial side view which shows the structure of the moving body 40 and its periphery is shown in FIG. 2, FIG. FIG. 2 is a view seen from the moving direction, and FIG. 3 is a view seen from the optical path direction. As can be seen from FIG. 2, the alternative optical collimator 13 is disposed below the optical collimators 11 and 12. That is, the substitute optical collimator 13 is not arranged on the plane on which the optical collimators 11 and 12 are arranged. With this configuration, the alternative optical collimator 13 can be located in the space between the eight optical collimator pairs and always located outside the optical path of the eight optical collimator pairs.

  The support shaft 44 is provided with a rotating shaft 46, and a prism 50 is provided at the tip of the rotating shaft 46. The replacement optical collimator 13, the support column 44, the rotation shaft 46, and the prism 50 move along the rail 30 integrally with the moving body 40. The axis defined by the rotation axis 46 is at a position penetrating the center of the prism 50. The prism 50 is configured to be rotatable around the rotation shaft 46 as an axis. Further, the prism 50 has reflection surfaces parallel to each other having an inclination angle with respect to the optical path direction at both ends thereof. As indicated by a line with an arrow in FIG. 2, when a light beam incident on the prism 50 is reflected by one reflecting surface and then reflected by the other reflecting surface and is emitted from the prism 50, the incident light beam and the outgoing light beam are emitted. The rays become parallel.

  As shown in FIG. 3, by rotating the prism 50, the reflecting surface of the prism 50 can be inserted into and removed from the optical path of the optical collimator pair. As shown by the solid line in FIG. 3, when one of the reflecting surfaces of the prism 50 is inserted in the optical path between the optical collimators 11 and 12, the other reflecting surface is configured to face the alternative optical collimator 13. Yes. At this time, the light emitted from the alternative optical collimator 13 is reflected by the two reflecting surfaces of the prism 50 as shown by the line with the arrow in FIG. The dotted line in FIG. 3 shows a state in which the prism 50 is rotated and the prism 50 is removed from the optical path between the optical collimators 11 and 12. At this time, the light emitted from the optical collimator 11 travels along a path that linearly connects the optical collimators 11 and 12, that is, the optical path 15, and enters the optical collimator 12. That is, the path of the optical signal incident on the optical collimator 12 is changed by inserting / removing the prism 50 with respect to the optical path. As described above, the prism 50 functions as a path switching unit. In order to determine the position of the prism 50 that realizes the two states with high reproducibility, a stopper 48 that restricts the rotation of the prism 50 is provided.

  The operation of the optical switch having the above configuration will be described. In a normal state, an optical signal is transmitted from the outside to each connector 20, optical signals are transmitted and received between the working line optical collimators 11 and 12, and each working line optical collimator pair is optically coupled. It becomes a state. For example, in a pair of optical collimators including optical collimators 11-1 and 12-1, light input from the connector 20 to the optical collimator 11-1 exits from the optical collimator 11-1, and then travels straight above the stage 32 to be light. The light enters the collimator 12-1 and is output from the connector 20 to the outside. The same applies to the other pairs of optical collimators. At this time, the prism 50 is in the state indicated by the dotted line in FIG. 3 and is not inserted in the optical path of the optical collimator pair, so that the optical coupling of each optical collimator pair is not blocked.

  Next, let us consider a case where some abnormality occurs in one of the working lines. As an example, let us consider a case where an abnormality occurs in the line to which the optical collimator 11-2 is connected. When such an abnormality occurs, the optical collimator 11-2 of the line in which the abnormality has occurred is switched to the spare optical collimator 13 for the spare line, and is replaced with the optical collimator 12-2 that was the coupling partner of the optical collimator 11-2. The optical collimator 13 is coupled. First, the moving body 40 is moved along the rail 30 by the moving body driving means 42, and the moving body 40 is stopped at a position where the optical collimator 12-2 and the alternative optical collimator 13 can be optically coupled. Since the prism 50 is in the state indicated by the dotted line in FIG. 3 while the moving body 40 is moving, the optical coupling of each pair of optical collimators is not blocked by the movement of the moving body 40. Thereafter, the prism 50 is rotated so that the state shown by the solid line in FIG. 3 is inserted, and the reflecting surface of the prism 50 is inserted into the optical path between the optical collimator 11-2 and the optical collimator 12-2. As a result, the light emitted from the alternative optical collimator 13 is sequentially reflected by the two reflecting surfaces of the prism 50 and then enters the optical collimator 12-2. That is, the substitute optical collimator 13 and the optical collimator 12-2 are optically coupled. In this way, it is possible to easily switch the connection of the optical signal that has been performed on the working line to one of the working line and the protection line. By moving the moving body 40, not only the optical collimator 11-2 but also other optical collimators can be switched in the same manner.

  Thereafter, when the optical collimator 11-2 is restored, the optical collimator 11-2 and the optical collimator 12-2 can be optically coupled by rotating the prism 50 so as to be detached from the optical path. In this way, switching from the protection line to the working line can be easily performed.

  As described above, according to the present embodiment, the path of the optical signal can be changed by the rotation of the prism 50 to switch between the alternative optical collimator 13 and the desired single optical collimator for the working line. The prism 50 can be rotated as necessary to be inserted into and removed from the optical path, and the substitute optical collimator 13 is always located outside the optical path between the pair of optical collimators. The pair of signals is not momentarily interrupted. Further, since the replacement optical collimator 13 is not fixedly arranged and can be moved in the column direction of the pair of optical collimators by the moving body 40, the replacement optical collimator 13 and the coupling partner optical collimator The coupling distance of is constant. Conventionally, since the coupling distance differs depending on the optical collimator of the coupling partner, the light beam cannot be optimized and a large coupling loss occurs. However, according to the present embodiment, since the coupling distance is constant, one optimized coupling distance can be adopted, and therefore, coupling loss can be kept low. For example, even when the number of channels increases, the coupling distance can be made constant by moving the substitute optical collimator 13 to a desired position. Therefore, according to the present embodiment, since there is no problem of coupling loss due to the increase in the number of channels as in the prior art, it is possible to provide an optical switch that can handle the increase in the number of channels. If it is desired to increase the number of channels, the number of optical collimators can be increased, and the length of the optical fiber of the rail and the alternative optical collimator 13 can be increased, so that the number of channels can be easily increased.

  By the way, in the above embodiment, if there is an optical path of an optical signal normally communicating within the moving range of the rotating prism 50, the optical signal line is disconnected, which is not preferable. Therefore, it is necessary to arrange the optical collimator for the working line in consideration of the interval of the optical collimator for the working line so that the adjacent optical collimator for the working line is not located within the movement range of the prism 50. However, if the moving range of the prism 50 is large, the interval between the adjacent optical collimators for the working line is widened, which is against the downsizing of the apparatus, which is not preferable. The modifications described below are configured in consideration of this point.

  FIG. 4 is a partial side view showing the configuration of an optical switch according to a modification of the above embodiment, and is a view seen from the optical path direction as in FIG. In this modification, a support rod is provided between the prism and the rotating shaft, and this is a feature that is different from the above embodiment. Hereinafter, description will be made by paying attention to this point, and redundant description of the same configuration will be omitted.

  In the modification shown in FIG. 4, a switching optical collimator 113 and a column 144 are placed on the moving body 40. The switching optical collimator 113 has the same configuration as that in the above embodiment, and is not located on the plane on which the eight optical collimator pairs are arranged, as in the above embodiment. It is always located outside the optical path between the collimator pair. However, as shown in FIG. 4, the positional relationship between the switching optical collimator 113 and the column 144 is different from that of the above embodiment.

  The support shaft 144 is provided with a rotation shaft 146. The rotating shaft 146 is provided with an elongated support rod 147 having a long axis in the radial direction of rotation, and a prism 150 is fixed to the tip of the support rod 147. The prism 150 has the same reflective surface as the prism 50 in the above embodiment. In the present modification, since the support rod 147 is provided between the prism 150 and the rotation shaft 146, the axis defined by the rotation shaft 146 does not penetrate the prism 150 and is located away from the prism 150. ing. The distance between the rotation shaft 146 and the prism 150 is specified by the support bar 147. The support rod 147 and the prism 150 can rotate integrally around the rotation shaft 146 with the rotation shaft 146 as an axis.

  Also in this modification, by rotating the prism 150 around the rotation axis 146, the alternative optical collimator 13 and the optical collimator 12 can be optically coupled or uncoupled. In FIG. 5, the prism 150 and the support rod 147 in a state where the switching optical collimator 113 and the optical collimator 12 are coupled are indicated by solid lines, and the prism in a state where the switching optical collimator 113 and the optical collimator 12 are not coupled. 150 and the support rod 147 are indicated by dotted lines. In this modification, the combined state is when the long side of the prism 150 is in a direction substantially perpendicular to the surface of the moving body 40. In order to determine the position of the prism 150 in the coupled state and the uncoupled state, stoppers 148 for restricting the rotation of the prism 150 are provided at two locations on the rotation path of the prism 150.

  The space required for the rotation of the prism 150 for forming the coupled state and the uncoupled state, that is, the movement range of the prism 150 varies depending on the distance between the rotation shaft 146 and the prism 150. The distance between the rotation shaft 146 and the prism 150 appears as the length of the support bar 147, and the support bar 147 functions as an adjusting unit that adjusts the moving range of the prism 150. In this modification, by providing the support rod 147, the distance between the rotating shaft 146 and the prism 150 is made longer than in the above embodiment. As a result, as shown in FIG. 4, the movement range of the prism 150 in this modification is smaller than that of the above embodiment. If the movement range of the prism 150 is small, the interval between the adjacent optical collimators for the working line can be narrowed for the reason described above. Since the component arrangement interval can be narrowed in this way, in this modified example, an effect that the apparatus can be further reduced in size as compared with the above embodiment can be obtained.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  In the above description, the input port group, the output port group, and the substitute port are configured by the optical collimator. However, the present invention is not limited to this. Further, although the case where the alternative optical collimator is switched to the optical collimator of the input port group has been described, the present invention is naturally applicable even when the light traveling direction is reversed, and the alternative optical collimator is used as the output port group. The optical collimator may be switched. The number of optical collimators constituting the input port group and the output port group is not limited to that described above, and can be arbitrarily determined.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a mechanical optical switch that switches connection between input and output of an optical signal, and in particular, to an optical switch that switches a part of a working line and a protection line in a system that transmits and receives multi-channel optical signals. Is possible.

It is a top view which shows the structure of the optical switch concerning embodiment of this invention. It is a partial side view which shows the structure of the optical switch of FIG. It is a partial side view which shows the structure of the optical switch of FIG. It is a partial side view which shows the structure of the optical switch concerning the modification of this invention. It is a top view which shows the structure of the conventional optical switch.

Explanation of symbols

1, 2, 11, 12 Optical collimator 4,40 Moving body 5,50 Prism 3,13 Replacement optical collimator 15 Optical path 20 Connector 30 Rail 32 Stage 42 Moving body driving means 44 Post column 46 Rotating shaft 48 Stopper

Claims (7)

A first port group comprising a plurality of ports through which optical signals are input and output, and a second port comprising a plurality of ports optically coupled to each port of the first port group by a predetermined distance and a predetermined optical path An optical switch for optically switching between at least one port of the group and a substitute port;
The replacement port located outside the optical path between the first port group and the second port group and moving in a direction intersecting the optical path;
An optical switch comprising: path switching means for switching the optical signal by changing the path of the optical signal by being inserted into and removed from the optical path. 2. The optical switch according to claim 1, wherein the first port group and the second port group are arranged on the same plane, and the substitute port is not arranged on the plane. The optical switch according to claim 1, wherein the first port group and the second port group are arranged in parallel, and the substitute port moves in the column direction. The optical switch according to claim 1, wherein the path switching unit has two parallel reflecting surfaces and rotates around a predetermined axis. 5. The optical switch according to claim 4, wherein the path switching unit is a prism formed with the two reflecting surfaces. 6. The optical switch according to claim 4, further comprising an adjusting unit that specifies a distance between the axis and the path switching unit and adjusts a moving range of the path switching unit. The optical switch according to claim 1, wherein the substitute port includes an optical fiber and collimating means for collimating light from the optical fiber.

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