JP2519233B2 - Multi-fiber batch switch for optical fiber - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber switch, and more particularly to a mechanical optical fiber switch capable of simultaneously switching single mode multi-core optical fibers.

(Prior Art and Its Problems) Generally, in a 1 × N switch for a single mode optical fiber, when N is set to about 100, practically necessary conditions are (1) low loss, and (2) vibration. It is stable against changes in the external environment such as temperature and temperature changes, (3) little crosstalk, and (4) high-speed switching. Especially for single mode (SM) fiber changeover switches, it is important to have low loss. To connect an SM fiber with a core diameter of 10 μm to 0.4 dB or less, the amount of misalignment between the two fibers must be adjusted. It is necessary to keep it below 1.5 μm.

An example of a conventional SM fiber changeover switch is shown in FIGS. 2 (a), (b), and (c), and its drawbacks will be described. 1A shows a waveguide type switch, in which 101 is a single-core optical fiber, 102 is a single-core optical fiber connector, 103 is an adapter, 104 is a substrate, 105 is a waveguide portion provided on the substrate 104, and 106. Is a switch section. The single-core optical fiber 101 can be switched from the connection state of # 1 → # 3, # 2 → # 4 to the connection of # 1 → # 4, # 2 → # 3 by the change of the refractive index of the switch unit 106. Yes (Reference: The Journal of the Institute of Electronics and Communication Engineers Vol.69, No, 3,
P279-280, March 1986).

This waveguide switch operates in 20 nsec by passing a current through the switch unit 106, but has the following drawbacks.

(1) The loss of the waveguide section 105 is as large as 3 to 6 dB.

(2) The waveguide 105 is connected to the optical fiber connector 102.
Since it is required on both sides of the connector, a loss of about 1 dB for two connectors is added, resulting in a large loss.

(3) The crosstalk of the switch unit 106 is as large as -20 dB.

(4) It is not easy to increase the number of terminals.

(5) There is a drawback that the connection state is inverted at a probability of 1/2 when the power source is cut off. Therefore, it is not practical at this point.

FIG. 2B shows a movable mirror type switch, which is 101 in the drawing.
Is a single-core optical fiber, 102 is a single-core optical fiber connector, 103
Is an adapter, 107 is a collimator lens, 108 is a case, 10
Reference numeral 9 indicates the movable mirror, and 110 indicates the moving direction of the movable mirror 109. In the figure, when the movable mirror 109 is at the position shown by the solid line, # 1 → # 2 of the single-core optical fiber 101 are coupled, but by moving the movable mirror 109 to the position shown by the broken line, the single-core optical fiber 101 is moved. The output port of can be switched to # 3 and # 4. This movable mirror switch has several
It operates at a relatively high speed in msec, but has the following drawbacks.

(1) Since the beam is collimated by the incident light by the collimator lens 107, the loss at the coupling portion between the lenses and the loss due to incomplete collimation are about 2 dB.

(2) 1d by connecting the connector of input port and output port
B loss occurs.

(3) Since the movable mirror 109 is used, the transmitted power fluctuates due to external vibration. Therefore, even if the case 108 is stuck with a finger, a variation of ± 0.5 dB occurs.

Therefore, the loss is large at 3 dB or more and the stability is low, which is not practical.

FIG. 1C shows a multi-core ferrule shift type switch, in which 101 is a single-core optical fiber, 102 is a single-core optical fiber connector, 103 is an adapter, 108 is a case, and 111 is a plurality of single-core optical fibers 101. Fixed sided multi-core ferrule, 1
12 is a shifting multi-core ferrule in which a plurality of single-core optical fibers 101 are arranged, 113 is a shifting direction, 114 is a drive coil for applying a shift force, 115 is a parallel leaf spring provided on both sides of the multi-core ferrules 111 and 112, 116 Is a driving iron core. In this switch, the tip of the optical fiber 101 incorporated in the shifting multi-fiber ferrule 112 arranged to face the multi-fiber ferrule 111 moves in the shift direction indicated by 113, so that # 2 of the single-fiber optical fiber 101 → From the state of # 6, # 1 →
The connection state can be switched to # 4, # 2 → # 5, # 3 → # 6. This multi-core ferrule shift type switch is about 10
It operates at a high speed of msec, but has the following drawbacks.

(1) The reproducibility of the shift amount of the multi-fiber ferrule is limited to about 2 μm, and it is difficult to provide the reproducibility of 1 μm or less required for the SM fiber, and therefore it cannot be applied to the SM fiber.

(2) The number of core wires to be switched is limited by the number of fibers that can be mounted on the multi-core ferrule.

(3) Since it has a movable portion, output fluctuations occur due to external vibration.

(4) Since the drive coil and the parallel leaf spring are used in the drive unit, there is a drawback that the connection state may be reversed at the time of power failure. Therefore, it has been difficult to realize a 1 × N (N is about 100) type low loss and stable switch for SM fiber by using a conventional switch.

An object of the present invention is to solve the above-mentioned drawbacks and provide a mechanical multi-fiber batch changeover switch for SM fibers, which has low loss, good reproducibility, is stable against external vibration, and operates at a relatively high speed. It is in.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a plurality of multi-fiber connector ferrules in which fitting pin holes and optical fibers with a large number of fibers are arranged are arranged in a predetermined direction. A fixed-side multi-fiber connector ferrule group; and a movable-side multi-fiber connector ferrule having the same configuration as the fixed-side multi-fiber connector ferrule and facing the fixed-side multi-fiber connector ferrule and movable in its array direction, One of the fitting pin holes on the moving or fixed multi-core connector ferrule has a fitting pin hole that can be inserted into and removed from the mating pin hole on the mating side, and the fitting pin hole reciprocates. We propose a multi-fiber batch switch for optical fibers, in which an operating mechanism for inserting and removing by movement is integrally connected.

(Operation) According to the present invention, the multicore connector ferrule to be switched and connected is selected by moving the moving side multicore connector ferrule, and the highly accurate axis alignment of the opposing multicore connector ferrules is performed by the reciprocating motion. The operation mechanism for performing is performed by the insertion plate of the fitting pin integrally connected. Further, when the switching operation is not performed, the connection state of the multi-fiber connector ferrule is locked by the fitting pin.

(Embodiment) FIG. 1 is a diagram for explaining a first embodiment of the present invention.
FIG. 3 is an explanatory view of the main parts used in the first embodiment, and FIG. 4 is an operation explanatory view of the first embodiment. In the figure, 1 is an optical fiber, 2 is a tape core wire in which 5 optical fibers 1 are arranged, 3 is a moving side multi-core connector ferrule, 4 is a moving case, 5 is a moving case mounting screw, 6 is a parallel movement bearing, and 7 Is a guide rail, 8 is a thin steel plate belt, 9 is a pulley, 10 is a DC servo motor, 11 is an optical rotary encoder that shares a rotation axis with the DC servo motor 10, 12 is a lead wire for a motor drive circuit, and 13 is a rotation speed. Lead wire for detection circuit, 14 fixed-side five-core connector ferrule, 15 fitting pin insertion hole, 16 fitting pin, 17 fitting pin clamp plate, 18 electromagnetic piston for extracting fitting pin, 18 ' Is a fitting pin insertion spring, 19 is an electromagnetic piston drive circuit lead wire, 20 is a fitting pin tip taper, 21 is an optical fiber end face, 22 is a slight gap, 23 is a fitting pin withdrawal movement amount, 24 Is the parallel movement of the moving side 5 core connector ferrule , 25 movement amount error, 26
Indicates the insertion movement amount of the fitting pin, and 27 indicates the force acting on the ferrule by the insertion of the fitting pin.

In FIG. 1, the moving-side five-core connector ferrule 3 is housed in a moving case 4, the moving case 4 is integrated with a parallel movement bearing, and is fixed to a thin steel plate belt 8 by a fixing screw 5. . The thin steel plate belt 8 is kept parallel to the guide rail 7 by a pulley 9 pivotally supported by the machine frame A, and is connected to the pulley 9 by a DC servo motor.
Driven by 10. DC servo motor 10 rotation angle is DC
It is detected by an optical rotary encoder 11 directly connected to the axis of the servo motor 10. A plurality of fixed-side five-core connector ferrules 14 are arranged in a row on the support base B, and the end face thereof is several μm between the end face of the moving-side five-core connector ferrule 3
Located through a slight gap in. Fixed side 5-core connector Ferrule 14 has a mating pin insertion hole 15 with a diameter of 0
A fitting pin 16 having a small diameter of about 0.5 μm is inserted. Every 6 fitting pins 16 are clamped by a fitting pin clamp plate 17, and the clamp plate 17 is an electromagnetic pin for extracting the fitting pin. The fixed piston 5 and the fitting pin insertion spring 18 'allow the fixed-side five-core connector ferrule 14 to project or dent from the end surface. The piston 18 contains a solenoid coil and is driven by passing a current through a lead wire 19 for a solenoid drive circuit.

FIG. 3 (a) is an explanatory view of the 5-core connector ferrule 3 or 14 incorporated in FIG. Mating pin insertion hole
15 is a hole diameter having a clearance of 0 to 1 μm with the fitting pin 16. The optical fiber end surface 21 of each single-core optical fiber 1 arranged in the center of the pair of fitting pin insertion holes 15 is located on the same plane as the ferrule end surface, and is perpendicular to the axis of the fitting pin insertion hole 15. Has become.

FIG. 3 (b) is an explanatory view of the fitting pin drive unit incorporated in FIG. In the figure, the fixed side five-core connector ferrule 14 has a fitting pin 16 inserted from below, and a plurality of fitting pins are inserted through a fitting pin clamp plate 17.
16 is simultaneously driven by an electromagnetic piston 18. A taper 20 is formed on the tip of the fitting pin 16, and the movable side 5-core connector ferrule 3 and the fixed-side 5 core connector ferrule 14 can be positioned by the DC servo motor 10 so that they face each other.
Even if there is an error of about 100 μm, the fitting pin 16 can be inserted into the movable-side five-core connector ferrule 3.

The operation of the optical switch according to the present invention will be described below with reference to FIG. The switching operation is shown in (a), (b),
The steps (c) and (d) are performed in this order. FIG. 4 (a) shows the state before switching. Opposing optical connector ferrules 3 and 14
The end faces face each other through a slight gap 22, and the fitting pin 16 aligns the optical axes of the optical fibers (not shown in the figure) of the two ferrules 3 and 14 with high precision. At this time, when the slight gap 22 is about 10 μm, in the SM fiber having a core diameter of 10 μm, the splice loss increase amount is about 0.01 by applying the refractive index matching agent in this gap.
It can be dB. A loss of about 0.01 dB is not a practical problem.

FIG. 6B shows a state in the middle of switching, in which the fitting pin 16 is moved by the amount of the arrow indicated by the reference numeral 23 by the movement of the electromagnetic piston 18, and the fitting pin 16 is lowered from the end face of the ferrule. .

Next, FIG. 6C shows a state in the middle of switching, in which the moving ferrule 3 has moved by the amount indicated by the arrow 24, and the amounts of the moving ferrule 3 and 14 on the moving side and the fixed side by the amount indicated by 25. It is out of alignment.

FIG. 7D shows a state in which the switching has been completed, the solenoid current of the electromagnetic piston 18 is cut off, and the spring 18 'operates to insert the fitting pin 16 into the moving ferrule 3 by the distance indicated by the arrow 26. As a result, the moving ferrule 3 moves in the direction indicated by the arrow 27, and the error 25 in the moving amount is eliminated.

Through the above process, the operation of the optical changeover switch according to the present invention is completed. The switching required time in this embodiment is about 5 msec for each operation of withdrawal and insertion of the fitting pin, the moving side ferrule is about 75 mm from the No. 1 ferrule on the fixed side to the No. 30 on the other end for about 75 mm. It was 15 msec, and the total operation time was about 30 msec.

In this embodiment, high-speed movement of the moving-side ferrule for selecting the ferrules to be switched and connected is performed by a positioning method with coarse resolution by controlling the motor rotation angle, and high-precision axis alignment of the opposing ferrules is fitted. By connecting and disconnecting pins, high-speed and highly accurate switching connection between multi-core ferrules is realized. In this embodiment, the overrun of the parallel movement amount of the ferrule and the positioning error due to the vibration, which occur when the positioning is roughly performed only by controlling the motor rotation, are instantaneously corrected by the forced high-precision axis alignment operation by inserting the fitting pin. Since it is possible to shift to a stable connection state between ferrules, stable switching operation is possible, and in the state where switching operation is not performed, the connection state of the ferrule is locked by the fitting pin, It has the feature that the connection status does not change even when vibration is applied to the device from the outside or the power is turned off. In addition, the optical loss of this switching device is only the splice loss between ferrules, and the average loss is about 0.5 dB in SM fiber.

As described above, the optical fiber mechanical switch according to the present invention has a high speed switching operation of several tens of msec, stability against external vibration, and low optical loss characteristics of about 0.5 dB.

In the present embodiment, the third (b) ferrule in which a 5-fiber optical fiber is mounted is used as the ferrule, but as an application, the adapter type ferrule 40 shown in FIG. 6 is used to become the standard of NTT. Switching of the single-core ferrule 41 for FC connector which is used can be performed in the same manner.

As yet another application, a configuration in which the fitting pin 16 and the electromagnetic piston 18 are attached to the moving ferrule 3 can be realized. In such a case, if the weight of the moving body can be reduced, high speed switching can be performed as in the embodiment of FIG. In this case, since the fitting pin only needs to be provided in the moving ferrule, the mounting of the fixed ferrule can be simplified.

FIG. 5 shows a second embodiment of the present invention. Fig. 5 (a)
In, the moving-side five-core connector is mounted on the moving-side multi-core connector ferrule insertion / extraction drive unit 28. No fitting pin or the like is inserted behind the fixed-side five-core connector ferrule 14. Other configurations are the same as those in FIG. Unit 28 is a translation bearing 6
It can be moved to any fixed 5-core connector ferrule position. FIG. 5 (b) is a perspective view of the unit 28 as seen from below. The ferrule 33, into which the fitting pin 34 is inserted and fixed, is mounted so that it can enter and leave the unit. Figure 5 (c) shows the unit
28 internal structure. The 5-core connector ferrule 33 is fixed to the parallel slide 30. The parallel slide 30 is supported by a parallel slide support rod 31 and moves in parallel in the vertical direction. Further, since the parallel slide 30 is pressed downward by the coil spring 32, it is pressed downward when the electromagnetic piston 29 is not operating. Therefore, the moving ferrule 33 is the fixed ferrule.
Mated and connected with 14. The electromagnetic piston 29 causes the lever 35 to move when an electric current is applied to the lead sensor connected to the power supply.
The driving point 37 of the is pulled in the direction of 39, and the parallel slide 30 is pushed upward at the position of the action point 38 of the lever. This lever
The use of 35 is a characteristic of the operation of the electromagnetic piston 29,
This is because the driving stroke length of the electromagnetic piston 29 needs to be shortened when a large pulling force and high-speed operation are required. Because of the above configuration, in order to perform the switching operation of the optical connector by this device, first, the electromagnetic piston 29 is driven so that the fitting pin 34 of the moving side ferrule 33 is completely removed from the fixed side ferrule 14. Push up the ferrule 33 on the moving side until it comes out.

Next, the unit 28 is moved along the slide 6 by the motor 10 to a designated position.

The drive current of the electromagnetic piston 9 is cut off. Then, the new fixed ferrule 14 is moved to the moving ferrule 33.
Of the movable ferrule 33 and the end surface of the fixed ferrule 14 are butted against each other,
Connections between the core fibers are made.

 This completes the operation.

Similar to the first embodiment, by using a light alloy, plastic, or the like as the material of the moving body, the ferrule itself which is driven up and down, the driving electromagnetic piston, and the like, the weight is reduced to realize a high-speed optical switch operation. Is possible. In any of these embodiments, as in the first embodiment of the present invention, it is possible to take advantage of the feature that the moving ferrule can be moved at high speed and the fitting pin can perform highly accurate positioning. Therefore, it is possible to operate multimode batch switch of single mode fiber with low loss of about 0.5 dB due to high speed in several tens of milliseconds.

(Effects of the Invention) As described above, according to the present invention, the moving-side multi-fiber connector ferrule is made to face the fixed-side multi-fiber connector ferrule to be connected at high speed, and the height of the opposing multi-fiber connector ferrules is increased. Since accurate axis alignment is performed at high speed by inserting / removing the mating pin, a high-speed and highly-accurate multi-fiber connector ferrule changeover switch operation is possible, and the mating pin has an operating mechanism that performs reciprocating motion of the mating pin. Since they are integrally connected, a new pin is inserted into the fitting hole and the old pin is pushed out every time the connection is switched, and the expensive fitting pin that requires high work precision is made disposable. There is no waste, and there is no fear that the pushed out fitting pin will hinder the movement of the multi-fiber connector ferrule. In addition, since the mechanism is a mechanism that locks the axial alignment state between the facing ferrules with a mating pin, compared to conventional mechanical switches, some type of optical signal is generated even when external vibration or power is cut off. It has the advantage that it is not affected by fluctuations.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of the first embodiment of the present invention. FIG. 2 (a) is an explanatory view of a conventional waveguide type switch,
FIG. 2B is an explanatory view of a conventional movable mirror type switch,
FIG. 2C is an explanatory diagram of a conventional multi-core ferrule shift type switch. 3 (a) and 3 (b) are perspective views of the main parts used in the first embodiment of the present invention. 4 (a), (b), (c), and (d) are operation explanatory views of the first embodiment of the present invention. FIG. 5 is an explanatory view of a second embodiment of the present invention, FIG. 5 (a) is an external perspective view, FIG. 5 (b) is a perspective view of a moving side five-core connector ferrule insertion / extraction drive unit, FIG. 5C is a sectional view of the moving-side five-core connector ferrule insertion / extraction drive unit. FIG. 6 is a perspective view showing another embodiment of the moving side connector ferrule. 1 ... Optical fiber, 2 ... Tape core wire, 3 ... Moving side multi-fiber connector ferrule, 4 ... Moving case, 5 ... Fixing screw, 6 ... Parallel moving bearing, 7 ... Guide rail, 8 ...... Thin steel sheet belt, 9 …… Pulley, 10 …… DC servo motor, 11 …… Optical rotary encoder, 12 ……
Lead wire for motor drive circuit, 13 ... Lead wire for rotation speed detection circuit, 14 ... Fixed 5-core connector ferrule, 15 ...
Mating pin insertion hole, 16 …… Mating pin, 17 …… Mating pin clamp plate, 18 …… Electromagnetic piston for extracting mating pin, 18 ′…
… Mating pin insertion spring, 19 …… Electromagnetic piston drive circuit lead wire, 20 …… Mating pin tip taper, 21 …… Optical fiber end face, 22 …… Slight gap, 23 …… Mating pin Pull-out movement amount, 24 …… Movement side 5-core connector ferrule parallel movement amount, 25 …… Movement error, 26 …… Mating pin insertion movement amount, 27 …… Force acting on ferrule by inserting mating pin .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Nagasawa 162 Shirane, Shirahoji, Tokai-mura, Naka-gun, Ibaraki Prefecture Nippon Telegraph and Telephone Corporation, Ibaraki Dentsu Communication Laboratory (56) Reference JP-A-63-170606 (JP, A)

Claims (1)

(57) [Claims] 1. A fixed-side multi-fiber connector ferrule group in which a plurality of multi-fiber connector ferrules in which fitting pin holes and a large number of optical fibers are arranged are arranged in a predetermined direction, and the fixed-side multi-fiber connector ferrule. And a movable side multi-core connector ferrule facing the fixed side multi-core connector ferrule and movable in the arrangement direction, one of the fitting pin holes of the movable side or the fixed side multi-core connector ferrule A fitting pin that can be inserted into and removed from the mating pin hole on the mating side is inserted into the mating pin hole, and an operating mechanism that performs an inserting and extracting operation by reciprocating motion is integrally connected to the mating pin hole. A multi-fiber batch switch for optical fibers.