Optical switch and optical device

Abstract

An optical switch (SW) comprises a plurality of input ports (P1-P4) and a plurality of output ports (Q1-Q4). The plurality of input ports are arranged at equal intervals around a rotation axis, the plurality of output ports are arranged at equal intervals around the rotation axis, the plurality of input ports are configured from a first input port (P1) for external connection and second input ports (P2-P4) for internal connection other than the first input port, and the plurality of output ports are configured from a first output port (Q1) for external connection and second output ports (Q2-Q4) for internal connection other than the first output port. The second input ports and the second output ports are connected by optical fibbers(FB2-FB4), combinations of connections between the input ports and output ports are switched by rotation around the rotation axis, the plurality of input ports and the plurality of output ports are simultaneously connected, and an optical signal propagates between the connected input port and output port.

Description

Optical switches and optical devices

[0001] The present disclosure relates to optical switches and optical devices.

[0002] Non-Patent Document 1 discloses a technology for connecting optical fiber cores at optical nodes using an optical cross-connect consisting of multiple optical switches. According to this technology, a rotary optical switch, in which optical fibers are arranged circumferentially, is used as an optical switch suitable for use in optical nodes installed outdoors, from the viewpoints of power saving and miniaturization.

[0003] Non-Patent Document 2 discloses a technique relating to an optical device that utilizes a plurality of optical switches and is capable of variably adjusting an optical line.

[0004] Chisato Fukai et al., “Multi-core fiber rotated optical switch,” Optical Fiber Technology 81 (2023) 103470. Kazunori Katayama et al., “Study on hybrid delay adjustment method for optical fiber line hitless switching system,” Institute of Electronics, Information and Communication Engineers, Optical Fiber Application Technology Study Group OFT2012-60, 2013.

[0005] According to the technology described in Non-Patent Document 1, by rotating a rotary optical switch, it is possible to realize a function of switching the output destination of an optical signal from the input side according to the number of channels. For example, by using multiple rotary optical switches, it is possible to configure an optical cross-connect. However, this technology is limited in its function to switching the connections between multiple input destinations and multiple output destinations.

[0006] Furthermore, according to the technology described in Non-Patent Document 2, the optical device occupies a relatively large volume. Therefore, when there is a limit to the volume of the location where the optical device is installed, it becomes difficult to apply this technology.

[0007] As such, there is a problem in that it is not easy to provide an optical switch with functions other than switching the connections between multiple input destinations and multiple output destinations while suppressing an increase in the capacity of the entire device including the optical switch.

[0008] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an optical switch and an optical device that can provide an optical switch with functions other than switching connections between multiple input destinations and multiple output destinations, while suppressing an increase in the capacity of the entire apparatus including the optical switch.

[0009] In order to solve the above-mentioned problems, the optical switch according to the present disclosure includes a plurality of input ports and a plurality of output ports. The plurality of input ports are arranged at equal intervals around a rotation axis, and the plurality of output ports are arranged at equal intervals around the rotation axis, and the plurality of input ports are composed of a first input port for external connection and a second input port for internal connection other than the first input port. The plurality of output ports are composed of a first output port for external connection and a second output port for internal connection other than the first output port. The second input port and the second output port are connected by optical fibers, and rotation around the rotation axis switches the connection combination of the input ports and the output ports, so that the plurality of input ports and the plurality of output ports are simultaneously connected, and optical signals propagate between the connected input ports and output ports.

[0010] According to the present disclosure, it is possible to provide an optical switch with functions other than switching the connections between a plurality of input destinations and a plurality of output destinations, while suppressing an increase in the capacity of the entire device including the optical switch.

[0011] Fig. 1 is a diagram illustrating an example of the configuration of an optical switch according to the present disclosure; Fig. 2 is a schematic diagram illustrating an example of a connection between an optical switch and an optical fiber in an optical device according to the present disclosure; Fig. 3 is a schematic diagram illustrating a path change of an optical transmission path in an optical device according to the present disclosure; Fig. 4 is a diagram illustrating an example of a configuration in which optical devices according to the present disclosure are connected in series.

[0012] Next, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description, the same components are designated by the same reference numerals and redundant description will be omitted.

[0013] 1 is a diagram showing an example of the configuration of an optical switch according to the present disclosure. The optical switch SW includes a plurality of input ports and a plurality of output ports.

[0014] 1 shows that the optical switch SW has input ports P1 to P4 and output ports Q1 to Q4. The number of input ports provided in the optical switch SW is not limited to four and may be two or more. The number of output ports provided in the optical switch SW is not limited to four and may be two or more.

[0015] The plurality of input ports P1 to P4 are arranged at equal intervals around the rotation axis AS, and the plurality of output ports Q1 to Q4 are arranged at equal intervals around the rotation axis AS.

[0016] For example, as shown in Fig. 1, the optical switch SW may have a rotation mechanism, and the input ports P1 to P4 and the output ports Q1 to Q4 may be arranged at equal intervals along the direction of rotation of the rotation mechanism. In Fig. 1, the input ports P1 to P4 are arranged at 90-degree intervals around the rotation axis AS of the rotation mechanism. Similarly, the output ports Q1 to Q4 are arranged at 90-degree intervals around the rotation axis AS of the rotation mechanism.

[0017] The rotation mechanism rotates gears using, for example, a motor (not shown) to change the angular positions of the output ports Q1 to Q4 relative to the input ports P1 to P4 around the rotation axis AS. In Fig. 1, the output ports Q1 to Q4 are arranged to face the input ports P1 to P4 in the direction of the rotation axis AS of the rotation mechanism.

[0018] 1, optical signals input to the input ports P1 to P4 are output from the output ports Q1 to Q4, respectively. This state corresponds to the state ST1 shown in FIG.

[0019] When the angular positions of the output ports Q1 to Q4 are changed by 90 degrees in the direction of rotation by the rotation mechanism from the state shown in Figure 1, the output ports Q2, Q3, Q4, and Q1 will face the input ports P1 to P4, respectively. This state corresponds to state ST2 shown in Figure 3.

[0020] When the angular positions of the output ports Q1 to Q4 are changed by 180 degrees in the direction of rotation by the rotation mechanism from the state shown in Figure 1, the output ports Q3, Q4, Q1, and Q2 will face the input ports P1 to P4, respectively. This state corresponds to state ST3 shown in Figure 3.

[0021] When the angular positions of the output ports Q1 to Q4 are changed by 270 degrees in the direction of rotation by the rotation mechanism from the state shown in Figure 1, the output ports Q4, Q1, Q2, and Q3 will face the input ports P1 to P4, respectively. This state corresponds to state ST4 shown in Figure 3.

[0022] As described above, optical signals are propagated between the opposing input and output ports. In this way, the rotation around the rotation axis AS switches the connection combinations of the input ports P1 to P4 and the output ports Q1 to Q4. Multiple input ports P1 to P4 and multiple output ports Q1 to Q4 are simultaneously connected, and optical signals are propagated between the connected input and output ports.

[0023] [Configuration of Optical Device] Fig. 2 is a schematic diagram showing an example of a connection between an optical switch and an optical fiber in an optical device according to the present disclosure. The optical device includes an optical switch SW and an optical fiber.

[0024] The plurality of input ports P1 to P4 are configured from a first input port P1 for external connection and second input ports P2 to P4 for internal connection other than the first input port P1.

[0025] The plurality of output ports Q1 to Q4 are configured from a first output port Q1 for external connection and second output ports Q2 to Q4 for internal connection other than the first output port Q1.

[0026] The second input ports P2 to P4 and the second output ports Q2 to Q4 are connected by optical fibers. In Fig. 2, the input port P2 and the output port Q3 are connected by the optical fiber FB2. The input port P3 and the output port Q4 are connected by the optical fiber FB3. The input port P4 and the output port Q2 are connected by the optical fiber FB4.

[0027] Here, the connection relationship between the second input ports P2 to P4 and the second output ports Q2 to Q4 via optical fibers will be expressed as "Q2→P4, Q3→P2, Q4→P3."

[0028] The connection relationship between the second input ports P2 to P4 and the second output ports Q2 to Q4 is not limited to the example given here.

[0029] The optical fibers FB2 to FB4 included in the optical device may differ from each other in at least one of the line length, the magnitude of optical loss, and the wavelength band in which light can propagate. In this way, each optical fiber may have different optical characteristics.

[0030] For example, the optical fibers FB2 to FB4 may have different line lengths. More specifically, the optical fibers FB2 to FB4 may have different lengths.

[0031] Furthermore, the optical fibers FB2 to FB4 may have different optical loss magnitudes. More specifically, optical attenuators that impart optical loss may be provided midway through the optical fibers FB2 to FB4. The magnitude of optical loss caused by the optical attenuators may differ for each optical fiber.

[0032] Furthermore, the optical fibers FB2 to FB4 may have different wavelength bands as the wavelength bands that can propagate. More specifically, different wavelength filters may be provided midway along the optical fibers FB2 to FB4.

[0033] Next, let us consider the size of the optical device. In the optical device according to the present disclosure, the second input ports P2 to P4 and the second output ports Q2 to Q4 are connected by optical fibers. For example, the size of the housing that houses the optical fibers is determined according to the distance between the second input port and the second output port in the optical switch SW and the allowable bending radius of the optical fibers.

[0034] More specifically, if the distance between the second input port and the second output port in the optical switch SW is about 7 cm and the allowable bending radius of the optical fiber is about 15 mm, the size of the housing that houses the optical fiber needs to be about 10 cm. Also, assuming that the housing has a size sufficient to accommodate the internal optical fiber wound therein, a dimension of 1 cm is required in the height direction of the housing from the outer dimensions of one optical switch SW. Assuming a storage configuration requiring multiple optical SWs, and assuming the height of a housing with 10 housings stacked on top of each other, one side of the housing in the height direction will be 10 cm. Therefore, the size of the housing for the optical device is 1L (1000 cm ３ ) is necessary.

[0035] For example, according to the technology described in Non-Patent Document 2, the volume occupied by an optical device is 496 L (496,000 cm ３ In comparison with this capacity, the estimated value of the housing size of the optical device according to the present disclosure, 1 L (1000 cm ３ ) is found to be sufficiently small.

[0036] 3 is a schematic diagram showing a change in the path of the optical transmission path in the optical device according to the present disclosure. Note that in state ST1, the connections between the second input ports P2 to P4 and the second output ports Q2 to Q4 are indicated by dotted lines, but in states ST2 to ST4, the connections are omitted.

[0037] In state ST1, output ports Q1 to Q4 are arranged to face input ports P1 to P4. State ST1 is represented by "P1⇒Q1, P2⇒Q2, P3⇒Q3, P4⇒Q4".

[0038] In state ST1, when observing the path from the first input port P1 for external connection to the first output port Q1 for external connection, it is "P1 ⇒ Q1." In other words, it is clear that the optical signal does not propagate through the optical fiber.

[0039] In state ST2, the output ports Q2, Q3, Q4, and Q1 face the input ports P1 to P4, respectively. State ST2 is expressed as "P1⇒Q2, P2⇒Q3, P3⇒Q4, P4⇒Q1."

[0040] In state ST2, when observing the path of an optical signal input from the first input port P1 for external connection until it is output from the first output port Q1 for external connection, it is found to be "P1 ⇒ Q2 ⇒ P4 ⇒ Q1." In other words, it is clear that the optical signal propagates through the optical fiber FB4.

[0041] In state ST3, the output ports Q3, Q4, Q1, and Q2 face the input ports P1 to P4, respectively. State ST3 is expressed as "P1⇒Q3, P2⇒Q4, P3⇒Q1, P4⇒Q2."

[0042] In state ST3, when observing the path of an optical signal input from the first input port P1 for external connection until it is output from the first output port Q1 for external connection, it is found to be "P1 → Q3 → P2 → Q4 → P3 → Q1." In other words, it can be seen that the optical signal propagates through the optical fiber FB2 and the optical fiber FB3.

[0043] In state ST4, the output ports Q4, Q1, Q2, and Q3 face the input ports P1 to P4, respectively. State ST4 is expressed as "P1⇒Q4, P2⇒Q1, P3⇒Q2, P4⇒Q3."

[0044] In state ST4, when observing the path taken by an optical signal input from the first input port P1 for external connection until it is output from the first output port Q1 for external connection, it is found to be "P1 → Q4 → P3 → Q2 → P4 → Q3 → P2 → Q1." In other words, it can be seen that the optical signal propagates through the optical fiber FB3, the optical fiber FB4, and the optical fiber FB2.

[0045] As described above, the optical fibers connected between the first input port and the first output port are changed by the rotation of the optical switch SW about the rotation axis AS. For example, in state ST1, the number of optical fibers connected between the first input port and the first output port is 0, whereas in states ST2 to ST4, the number of optical fibers connected between the first input port and the first output port is changed between 1, 2, and 3, respectively.

[0046] Thus, rotation about the axis of rotation can change the optical properties of the path formed between the first input port and the first output port of the optical switch.

[0047] [Configuration of Series Connection of Optical Devices] Fig. 4 is a diagram showing an example of a configuration in which optical devices according to the present disclosure are connected in series. In Fig. 4, the optical device includes optical switches SW1 to SW3.

[0048] The output port Q1 of the optical switch SW1 is connected to the input port P1 of the optical switch SW2. The output port Q1 of the optical switch SW2 is connected to the input port P1 of the optical switch SW3. In this way, the multiple optical switches SW1 to SW3 are connected in series via the first input ports and first output ports.

[0049] The number of optical switches included in the optical device is not limited to 3, and may be any number equal to or greater than 2. In other words, in the optical device, n optical switches (n is a natural number equal to or greater than 2) are connected in series via the first input port and the first output port.

[0050] Each of the optical switches SW1 to SW3 has m input ports and m output ports (m is a natural number). In Fig. 4, the optical switches SW1 to SW3 are shown to have four input ports and four output ports.

[0051] In addition, among the n optical switches, the line length of each optical fiber (line length of each optical fiber) connected to the second input port and the second output port of the jth optical switch (j is a natural number in the range of 1≦j≦n) is "m ｊ－１ ×L" (L is a predetermined length).

[0052] When the optical device has one optical switch, the line length of each optical fiber (line length of each optical fiber) connected to the second input port and the second output port is set to "L" (L is a predetermined length).

[0053] In this way, in a configuration in which optical switches are connected in series, by switching the combination of connections of input ports and output ports in each optical switch, the line length of the optical fiber connected between the first input port and the first output port in the j-th optical switch (j is a natural number in the range of 1≦j≦n) can be set to "m ｊ－１ ×L×k” (k is an integer in the range of 0≦k≦m−1).

[0054] Furthermore, when viewing the entire optical device, the line length of the optical fiber connected between the first input port of the first optical switch (optical switch SW1) and the first output port of the last optical switch (optical switch SW3) among the optical switches connected in series is defined as "L×k" (k is 0≦k≦m ｎ It can be set as an integer in the range of -1.

[0055] The number of input ports and output ports provided may differ for each optical switch.

[0056] [Effects of the Embodiments] As described in detail above, the optical switch according to the present disclosure includes a plurality of input ports and a plurality of output ports. The plurality of input ports are arranged at equal intervals around the rotation axis, and the plurality of output ports are arranged at equal intervals around the rotation axis. The plurality of input ports are composed of a first input port for external connection and a second input port for internal connection other than the first input port. The plurality of output ports are composed of a first output port for external connection and a second output port for internal connection other than the first output port. The second input port and the second output port are connected by optical fibers, and rotation around the rotation axis switches the connection combinations of the input ports and the output ports, so that the plurality of input ports and the plurality of output ports are simultaneously connected, and optical signals propagate between the connected input ports and output ports.

[0057] This allows the optical switch to have functions other than switching between multiple input and output destinations, while suppressing the increase in capacity required by the entire device including the optical switch.By expanding the functionality of the rotary optical switch, it is possible to configure an optical device that can switch the state of the optical fiber between the input and output sides using only a single rotary optical switch.

[0058] An optical device according to the present disclosure includes the optical switch described above and optical fibers, each of which may have a different line length, a magnitude of optical loss, or a wavelength band that can be propagated.

[0059] This makes it possible to configure an optical device that can change the state of the optical fiber, such as the line length, optical loss, and return loss of the optical fiber.

[0060] Furthermore, in the optical device according to the present disclosure, the optical switch may include m input ports and m output ports (m is a natural number), and the line length of each optical fiber connected to the second input port and the second output port in the optical switch may be "L" (L is a predetermined length), and the line length of the optical fiber connected between the first input port and the first output port may be set to "L×k" (k is an integer in the range of 0≦k≦m−1) by rotation around the rotation axis.

[0061] This makes it possible to configure a small optical device using an optical fiber line, in which the line length can be adjusted continuously over a wide dynamic range.

[0062] In addition, in the optical device according to the present disclosure, n optical switches (n is a natural number of 2 or more) may be connected in series via first input ports and first output ports. The optical switches may include m input ports and m output ports (m is a natural number), and the line lengths of the optical fibers connected to the second input ports and the second output ports of the jth optical switch (j is a natural number in the range of 1≦j≦n) may be "m ｊ－１× L (L is a predetermined length), and the line length of the optical fiber connected between the first input port and the first output port of the j-th optical switch is "m ｊ－１ ×L×k (k is an integer in the range of 0≦k≦m−1).

[0063] This makes it possible to configure a small optical device using optical fiber lines with a wide dynamic range and continuously adjustable line length by combining multiple functionally expandable rotary optical switches.

[0064] Although the contents of the present disclosure have been described above based on the embodiments, the present disclosure is not limited to these descriptions, and various modifications and improvements are possible, which will be apparent to those skilled in the art. The descriptions and drawings that form part of this disclosure should not be understood as limiting the present disclosure. Various alternative embodiments, examples, and operating techniques will be apparent to those skilled in the art from this disclosure.

[0065] Of course, the present disclosure includes various embodiments not described herein. Therefore, the technical scope of the present disclosure is defined only by the invention-specifying matters according to the scope of the claims that are appropriate from the above description.

[0066] AS Rotation axis FB2 to FB4 Optical fiber P1 to P4 Input port Q1 to Q4 Output port SW, SW1 to SW3 Optical switch ST1 to ST4 Status

Claims

1. An optical switch having a plurality of input ports and a plurality of output ports, wherein the plurality of input ports are arranged at equal intervals around a rotation axis, and the plurality of output ports are arranged at equal intervals around the rotation axis, the plurality of input ports consisting of a first input port for external connection and a second input port for internal connection other than the first input port, and the plurality of output ports consisting of a first output port for external connection and a second output port for internal connection other than the first output port, the second input port and the second output port are connected by optical fiber, and the combination of connections of the input ports and the output ports is switched by rotation around the rotation axis, and the plurality of input ports and the plurality of output ports are connected simultaneously, and optical signals are propagated between the connected input ports and the output ports.

2. An optical device comprising the optical switch according to claim 1 and the optical fibers, wherein at least one of the line length, the magnitude of optical loss, and the wavelength band that can be propagated differs for each of the optical fibers.

3. An optical device comprising the optical switch according to claim 1 and the optical fiber, wherein the optical switch comprises m input ports and m output ports (m is a natural number), the line length of each of the optical fibers connected to the second input port and the second output port in the optical switch is "L" (L is a predetermined length), and the line length of the optical fiber connected between the first input port and the first output port is set to "L x k" (k is an integer in the range of 0≦k≦m-1) by rotation around the rotation axis.

4. An optical device comprising the optical switch according to claim 1 and the optical fiber, wherein n (n is a natural number of 2 or more) of the optical switches are connected in series via the first input port and the first output port, the optical switch comprises m (m is a natural number) of the input ports and m (m is a natural number) of the output ports, and the line length of each of the optical fibers connected to the second input port and the second output port of the jth (j is a natural number in the range of 1≦j≦n) optical switch is "m ｊ－１ × L (L is a predetermined length), and the line length of the optical fiber connected between the first input port and the first output port of the j-th optical switch is increased by rotation around the rotation axis by "m ｊ－１ ×L×k (k is an integer in the range of 0≦k≦m−1).

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