JP2001242397A - Optical switch and optical switch module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical switch usable without impediment within a fixed temperature range even in a cold district. SOLUTION: This switch is the optical switch provided with an optical fiber switch means for moving/connecting at least one line of movable side optical fiber for plural fixed side optical fibers and a package for housing the optical fiber switch means, and uses the optical switch provided with a lagging member in the package. As the lagging member, a heat insulator or a heater is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical switch used in the field of optical communication. In particular, the present invention relates to an optical switch that can be stably installed on a printed circuit board.

[0002]

2. Description of the Related Art With the development of optical communication, optical fiber communication networks have long optical paths and complicated branches. In such an environment, the use of switching the optical path (transmission path) of an optical fiber between lines in an optical communication device or an optical transmission device is increasing, and many optical switches are used. Looking at the optical switch in the switching method, there is a type that switches the traveling direction of light by changing the refractive index and phase of the optical path electrically or optically, or switches the traveling direction of light by moving the optical path mechanically Methods and the like have been developed. As a low-loss optical switch that realizes precise driving, the latter mechanical optical switch is promising. In terms of the number of branches of an optical switch, a 1 × 2 type optical switch in which one input optical fiber is switched by two output optical fibers, a 1 × m type optical switch in which the end faces of a large number of optical fibers face each other, or n × m Type optical switch. In addition to the purpose of switching, in addition to normal line switching, failure recovery is used for switching a disconnected transmission path to another unbroken path, and maintenance and inspection is used for switching optical communication network lines in a building or area. Etc. are also used.

A conventional optical switch is disclosed in, for example,
No. 85522. This optical switch is an optical switch that switches two optical paths by moving two plugs, which position and fix an optical fiber, in contact with each other and moving one plug in parallel with the other plug.
It has a guide pin, a hole for holding the guide pin, and a hole for sliding the guide pin inside for realizing precise parallel movement. In this configuration, the switching mechanism of the optical switch is housed in an open container. There is a configuration in which the parallel movement of the plug is performed by an actuator using electromagnetic force.

[0004]

In a cold region, the dimensions and characteristics of each member used in an optical switch are changed as compared with a temperature near room temperature. Therefore, the mechanical operation speed and optical characteristics of the optical switch may be reduced. SUMMARY OF THE INVENTION An object of the present invention is to provide an optical switch that can be used without any trouble in a constant temperature even in a cold region.

[0005]

An optical switch according to the present invention comprises:
An optical switch comprising: an optical fiber switching unit that moves and connects at least one movable optical fiber to a plurality of fixed optical fibers; and a package that stores the optical fiber switching unit, wherein the package includes a heat insulating unit. Is provided.

Another optical switch according to the present invention is characterized in that in the above-mentioned present invention, the heat retaining means is a heater. Here, the heater refers to a member that generates heat by passing an electric current. The heater is set to a package temperature of 0
It is also possible to replace with a thermostat that maintains the temperature within the range of 40 ° C. to 40 ° C. This heater stabilizes the temperature of the optical switch at room temperature or within a temperature range near the room temperature.
Variations in optical characteristics can be suppressed. A configuration (for example, a waveguide type optical switch) that switches an optical path by moving or changing the phase of the refractive index matching material by local heating is different from the configuration of the present application.

Another optical switch of the present invention is characterized in that, in the above-mentioned present invention, the heat retaining means is a heat insulating material.
This heat insulating material covers the surface of the package. It is preferable to cover the entire optical switch or to cover a portion other than the conductive path (electrode pin or electric wire) connected to the optical switch with a heat insulating material in order to keep the temperature.

In another optical switch according to the present invention, in the optical switch according to the present invention, the optical fiber switching means includes: a fixed block for fixing a fixed optical fiber; a movable block for supporting an end of the movable optical fiber; A magnetic circuit for moving the block in parallel may be provided on one surface of the substrate, and the heater may be provided on the other surface of the substrate.

In another optical switch according to the present invention, in the optical switch according to the present invention, the package includes a housing and a lid, and the heater is provided on at least one inner surface of the housing or the lid. It can be configured. Providing a heater on the inner surface rather than the outer surface of the package makes the shape compact and improves the efficiency of warming the optical switch.

In a conventional optical switch, an optical signal is transmitted between opposed optical fibers via air. Then
A difference in the refractive index between air and an optical fiber may cause a loss of an optical signal. In order to suppress such a loss, a refractive index matching agent is provided between opposing optical fibers. However, the temperature around the optical switch is minus 10
When the temperature is lower than or equal to ° C., the viscosity of the refractive index matching agent increases. At this time, the load on driving the optical fiber switching means (for example, the actuator) increases, and a large current flows through the actuator, which is not preferable. In another optical switch according to the present invention, by providing a heat retaining means to keep the temperature of the optical switch at room temperature or a temperature in the vicinity thereof, the load on the actuator can be suppressed to a predetermined range.

An optical switch module according to the present invention is an optical switch module provided with any one of the optical switches according to the present invention, wherein: a means for measuring a temperature inside or near the optical switch; In this case, there is provided a means for supplying a warm-up current to the heater. As means for measuring the temperature,
A general temperature sensor or a configuration in which the temperature is converted from the electric resistance value of a heater and used as a temperature sensor can be used. The means for supplying current may be any of a type that continues to supply current while the temperature is equal to or lower than the threshold, a type that supplies current for a certain period of time, and a type that stops supply of current when the temperature reaches another threshold. Or can be.
Further, the threshold value can be set to various values because the radiation efficiency varies depending on the ambient temperature, the material of the package, the viscosity characteristics of the refractive index matching agent filled in the package, the shape and material of the module, and the like. For example, it is preferable that the temperature is set in the range of 0 ° C. to 10 ° C.

Another optical switch module according to the present invention is an optical switch module provided with any one of the optical switches according to the present invention, wherein an external sensor for measuring a temperature near the optical switch module and a temperature inside the optical switch are provided. An internal sensor that measures the temperature of the heater when the temperature detected by the external sensor is equal to or lower than a threshold, the heater is energized, and when the temperature detected by the internal sensor is equal to or higher than the driving temperature, It is characterized by including a control circuit for stopping energization. For example, if the control circuit is 1
Individual IC packages can also be used.

Another optical switch module according to the present invention is an optical switch module provided with any one of the above optical switches according to the present invention, wherein the optical switch module receives a drive signal for switching an optical path of the optical switch and measures the temperature of the optical switch. A control circuit for performing, a switching current supply unit for the optical fiber switching unit, and a heating current supply unit for the heater, the control circuit turning on and off the switching current supply unit and turning on and off the heating current supply unit. It is characterized by performing. A delay circuit that delays the supply of the switching current more than the supply of the warm-up current may be provided. Further, the delay circuit may be incorporated in an IC of the control circuit. Also, the configuration of the optical switch module can be simplified by combining the current supply means into one and changing the path to be energized by the electric circuit or the electronic circuit.

According to another aspect of the present invention, there is provided an optical switch module provided with any one of the above-described optical switches, wherein the temperature inside or near the optical switch is within a predetermined temperature range. To detect
It is characterized by comprising means for outputting or displaying a signal.

Another optical switch module according to the present invention is an optical switch module provided with any one of the optical switches according to the present invention, wherein a temperature inside or near the optical switch is detected, and the detected temperature is within a predetermined range. When it is not inside, an interlock that does not receive the switching signal of the optical switch is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical switch according to the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of an optical switch according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the optical switch of FIG. 1 along the directions of the optical fibers 1f and 1g. FIG. 3 is a sectional view of an optical switch according to another embodiment of the present invention. FIG. 4 is a cross-sectional view of the optical switch of FIG. 3 as viewed along the directions of the optical fibers 1f and 1g.
FIG. 5 is a schematic diagram illustrating a heater used in the embodiment of the present invention. FIG. 6 is a flowchart illustrating an operation example of the optical switch module. FIG. 7 is a schematic diagram of an optical switch module according to one embodiment of the present invention. FIG. 8 is a flowchart illustrating an operation example of the optical switch module.

(Embodiment 1) An optical switch of the present invention is shown in an exploded state in a perspective view of FIG. In the figure, the optical switch is configured such that a lid 3 provided with a pair of electrode pins 2a and a heater 1p is provided on a ceramic housing 1 having a pair of electrode pins 2b and optical switch switching means. Although the state where the lid 3 is removed is shown to facilitate the explanation of the internal configuration of the optical switch, the lid 3 is actually joined to the housing 1 along the dotted line. This optical switch drives the optical fiber switching means by changing the direction of the current flowing through the electrode pin 2b,
By changing the combination of the fixed-side optical fiber 1g and the movable-side optical fiber 1f, the optical path of the laser light incident from the movable-side optical fiber is switched.

The recess provided on one side of the lid 3 is
It corresponds to a pair of electrode pins 2b provided on the housing 1. Two metal films 2c are provided on the other side surface of the lid.
The metal film 2c wrapped around the front and back surfaces of the lid. The electrode pins 2a were joined to the front surface side, and the heater 1p was joined to the back surface side. A current (current for warming-up) was supplied to the electrode 2a thus configured for a predetermined time, and the electrode 2a was used for warming up the optical switch. Here, the warm air means that the temperature inside the optical switch is in a range of about 0 ° C. to 40 ° C. In the figure, since the zigzag-shaped heater 1p is provided on the back surface of the lid 3, it is shown by a dotted line. Although not shown, a space between the optical fibers 1f and 1g arranged opposite to each other is filled with a refractive index matching agent, and a portion where the optical fiber is led to the outside so as not to leak out, and a joint portion between the housing 1 and the lid 3 are formed. It was sealed with an adhesive.

The optical fiber switching means of the optical switch shown in FIG. 1 will be described in detail. The optical fiber switching means provided inside the housing 1 includes a fixed block 1c and a movable block 1c.
b, fixed block 1d, electromagnet 1y for moving movable block 1b along the x-axis, terminal 1h connecting electromagnet 1y and electrode pin 2b, movable optical fiber 1f for inputting an optical signal, and fixed for outputting an optical signal. A side optical fiber 1g is provided. The two movable-side optical fibers 1f are fixed to a fixed block 1c on the way, and the tips are provided on the movable block 1c. The four fixed-side optical fibers 1g had their tips provided on the fixed block 1g. The movable block 1c and the fixed block 1d are respectively provided with optical fibers 1f and 1g provided respectively.
And the end face of the same. An optical signal (laser light) can be transmitted between the opposing optical fibers. Electromagnet 1y
Has a configuration in which a coil is wound around a U-shaped magnetic yoke, and a fixed block 1d and a permanent magnet 1e are arranged between the ends of the U-shape. By changing the direction of the current flowing through the coil wound around each of the arms of the magnetic yoke, the movable block 1b is moved in parallel between the tips of the magnetic yoke, and the combination of the opposing connections of the optical fiber 1f and the optical fiber 1g is changed. Could be changed. Two protruding carbide pins were provided on the movable block 1b as stoppers for parallel movement. The fixed block 1d was provided with two wide holes for inserting the carbide pins. By the parallel movement of the carbide pin inside the wide hole, when the movable block moved in parallel, it was possible to approach the magnetic yoke while leaving a gap with one end of the magnetic yoke. In order to make the description easy to understand, in FIG. 1, the optical fibers 1f and 1g are shown.
The description of the coating covering is omitted.

FIG. 2 is a sectional view of FIG. 1 taken along the y-axis and the z-axis. The housing 1 and the lid 3 were joined, and the inside thereof was filled with a refractive index matching agent 4. The heater 1p was provided so as to substantially cover the inner surface of the lid 3 (a flat portion on the back surface). The fixed block 1c, the fixed block 1d, the permanent magnet 1e, and the magnetic yoke 1y were fixed on the glass substrate 1k joined in the housing. The end face of the fixed-side optical fiber 1g fixed by the fixed block 1d was opposed to the end face of the movable-side optical fiber 1f provided with the movable block 1b. As another embodiment, a configuration in which the outer surface of the package is covered with a sheet-like heat insulating material instead of providing a heater in the optical switch of FIG. 1 was studied. At this time, the outer surface of the optical switch was covered with the heat insulating material so that the electrode pins protruded from the heat insulating material. In this way, a decrease in the internal temperature of the optical switch can be suppressed without connecting a plurality of power supplies to the optical switch. Furthermore, it goes without saying that by providing both the heat insulating material and the heater in the optical switch, a decrease in the internal temperature of the optical switch can be more effectively suppressed.

(Embodiment 2) FIG. 3 is a perspective view and FIG. 4 is a sectional view of another embodiment of the optical switch.
This optical switch had the same function as that of FIG. 1 in switching the optical fiber. However, the difference is that the heater 1p is provided on the glass substrate 1k housed in the housing 1 and that the electrode pins 2a 'for supplying electricity to the heater are provided not on the lid but on the housing. The optical switch shown in FIG.
A glass substrate provided with optical switch switching means and the like was provided inside a ceramic housing 1 in which b and a pair of electrode pins 2a 'were bonded, a lid 3 was bonded to the housing 1, and the inside was filled with a refractive index matching agent. The configuration was adopted. The electrode pin 2b supplies current to the optical switch switching means, and the electrode pin 2a 'supplies current to the heater.

As shown in FIGS. 3 and 4, the optical switch switching means is provided on one surface of the glass substrate 1k.
c, a movable block 1b, a fixed block 1d, an electromagnet 1y for moving the movable block 1b along the x axis, and an electromagnet 1
A terminal 1h connecting y to the electrode pin 2b, a movable optical fiber 1f for inputting an optical signal, and a fixed optical fiber 1g for outputting an optical signal are provided. Further, a heater 1p for heating the optical switch was fixed to the other surface of the glass substrate 1k with an adhesive. Thus, the glass substrate 1 k provided with the optical switch switching means and the heater is provided in the housing 1, and the cover 3 is provided.
After bonding, the inside was filled with a refractive index matching agent 4 and sealed. The heater 1p and the housing 1 were joined via an adhesive.

FIG. 5 is a schematic view showing an example of a heater applied to the present invention. FIG. 5A shows a resistance pattern 42 mainly composed of carbon or silicon carbide on a glass substrate 41.
This is a heater formed with. The optical switch provided with the glass substrate can heat the refractive index matching agent in the package and heat up the entire optical switch by supplying electricity from the terminal 43. In FIG. 5B, a thin film 42a made of a material having a high electric resistance is formed and patterned on a ceramic substrate 41a by sputtering, and a conductive wire 46 is provided as a heater. Further, a thin film resistor 47 whose electric resistance value shows temperature dependency is formed and patterned by sputtering, and an electrode conductor 48 is provided to form a temperature sensor. Here, a silicon carbide-based material having high electric resistance was used as a sputtered film used as a heater. The specific resistance of silicon carbide is 0.08
２2 (Ω · cm), and the resistance value is larger than that of the NiCr alloy material or the carbon film by two digits or more.

(Embodiment 3) FIG. 6 illustrates the operation of an optical switch module according to an embodiment of the present invention. In this optical switch module, the optical switch of the first embodiment is controlled by a control circuit. First, a switching signal for instructing switching of an optical switch is transmitted from an optical communication network incorporating an optical switch module to a control circuit. Next, the control circuit that has received the switching signal measures the electric resistance value of the heater provided in the optical switch, and measures the temperature inside the optical switch by converting the resistance value into a temperature.
Next, the control circuit determines whether or not the measured temperature is a temperature (driving temperature) sufficient to switch the optical switch (6-a). If the temperature is sufficient (ie, YES),
An optical switch is switched by supplying a switching current to the optical fiber switching means. Conversely, if the temperature is not sufficient (ie, N
O), a current for warming is supplied to the heater for a predetermined time, and the temperature is measured again. Here, the drive temperature is determined (6-b), and the switching current is supplied.

(Embodiment 4) FIG. 7 shows the configuration of an optical switch module according to another embodiment. The optical switch module 50 includes an optical switch 5 on a printed circuit board 51.
2, a control IC 62, an external temperature sensor 63, a switching current supply unit 64, and a warm-up current supply unit 65. The optical switch 52 has a pair of terminals 53 for supplying a switching current to the optical fiber switching means, a heater 54 provided in the optical switch, and an internal temperature sensor 55. The driving IC 62 was connected via a wiring 67 so that an electric signal could be sent to each component. FIG. 7 shows a state in which the input light (laser light) introduced from the input side optical fiber 58 is output to one output side optical fiber 56 by an optical switch as an initial state.

FIG. 8A shows a procedure for keeping the temperature of the optical switch constant by the external temperature sensor and the internal temperature sensor so as not to drop below a predetermined value in the state of FIG. First, in a state of waiting for a switching signal, the temperature of the optical switch module is measured by the external temperature sensor 63. The control IC 62 determines whether or not this temperature is lower than a preset threshold (8-a). If the temperature is suitable for driving, the switching signal wait state is maintained. However, if the temperature is not suitable for driving or the speed of the temperature decrease is remarkable, the warm-up current is set to be supplied. Control IC 62
When a signal for instructing energization is sent to the warm-up current supply unit 65 from the, the warm-up current flows from the warm-up current supply unit 65 to the heater 54 for a predetermined time. Next, the temperature inside the optical switch is measured by the internal temperature sensor 55. This temperature is determined by the control IC 62 (8-b). If the temperature is equal to or higher than the temperature suitable for driving (driving temperature), the process returns to the switching signal waiting state. If the temperature is lower than suitable for driving, the process for supplying the warm-up current is set to be repeated.
By maintaining the temperature in the optical switch in this manner, when a switching signal for instructing switching of the optical switch is transmitted from the signal terminal 66 to the control IC 62, the control IC sends the switching current supply means 64 A signal for instructing energization is transmitted, and a switching current flows from the switching current supply unit 64 to the terminal 53. Thus, the optical switch smoothly switches as shown in FIG. 8B, and the input light introduced from the input optical fiber 58 is output to the other output optical fiber 57.

(Embodiment 5) The operation of an optical switch module according to another embodiment of the present invention will be described. The optical switch module includes an optical switch, a heater provided in the optical switch, a warm-up current supply unit that supplies electricity to the heater, a switching current supply unit that supplies electricity to an optical fiber switching unit in the optical switch, and a delay circuit. A temperature sensor provided near the optical switch is provided on a printed circuit board. With this configuration, when a decrease in the outside air temperature is detected by the temperature sensor, first, a warm-up current is supplied from the warm-up current supply unit to the heater for a predetermined time. At this time, the switching current supply means is set to operate after a predetermined time has elapsed since the warm-up current supply means was operated using the delay circuit.

[0028]

As described above, by using the configuration of the present invention, it is possible to obtain an optical switch which can be used within a constant temperature even in a cold region and has a reduced load on the optical fiber switching means.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an optical switch according to the present invention.

FIG. 2 is a sectional view of the optical switch of FIG. 1;

FIG. 3 is a sectional view of another optical switch according to the present invention.

FIG. 4 is a sectional view of the optical switch of FIG. 3;

FIG. 5 is a schematic diagram illustrating a heater used in the embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation example of the optical switch module according to the embodiment of the present invention.

FIG. 7 is a schematic view of an optical switch module according to one embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation example of the optical switch module according to the embodiment of the present invention.

[Explanation of symbols]

1 housing, 1b movable block, 1c fixed block,
1d fixed block, 1e permanent magnet, 1f movable optical fiber, 1g fixed optical fiber, 1k glass substrate, 1h terminal, 1y magnetic yoke, 1p heater, 2a electrode pin, 2a 'electrode pin, 2b electrode pin, 2C metal film, 3 Lid, 4 index matching agent, 50
Optical switch module, 51 Printed circuit board, 52 Optical switch, 53 terminal, 54 Heater, 55 Internal temperature sensor, 56 57 Output side optical fiber, 58
Input side optical fiber, 62 Control IC, 63 External temperature sensor, 64 Switching current supply means, 65 Warm current supply means, 66 Signal terminal, 67 Wiring

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masaya Horino 502, Kandachicho, Tsuchiura-shi, Ibaraki F-term in Machinery Research Laboratory, Hitachi, Ltd. (Reference) 2H041 AA14 AB19 AC04 AZ06 5K002 AA07 BA06 CA11 FA01

Claims (11)

[Claims] 1. An optical switch comprising: an optical fiber switching means for moving and connecting at least one movable optical fiber to a plurality of fixed optical fibers; and a package containing the optical fiber switching means. An optical switch, wherein the package is provided with heat retaining means. 2. The optical switch according to claim 1, wherein said heat retaining means is a heater. 3. The optical switch according to claim 1, wherein said heat retaining means is a heat insulating material. 4. The optical switch according to claim 2, wherein
The optical fiber switching means has, on one surface of the substrate, a fixed block for fixing the fixed-side optical fiber, a movable block for supporting the end of the movable-side optical fiber, and a magnetic circuit for moving the movable block in parallel. An optical switch, wherein the heater is provided on the other surface of the substrate. 5. The optical switch according to claim 2, wherein
The optical switch, wherein the package comprises a housing and a lid, and the heater is provided on at least one inner surface of the housing or the lid. 6. An optical switch module provided with the optical switch according to claim 2, wherein a means for measuring a temperature inside or near the optical switch, wherein the temperature is equal to or less than a threshold value An optical switch module comprising means for supplying a warm-up current to the heater when the above condition is satisfied. 7. An optical switch module provided with the optical switch according to claim 2, wherein an external sensor for measuring a temperature near the optical switch module and a temperature inside the optical switch. An internal sensor for measuring, energizing the heater when the temperature detected by the external sensor is equal to or lower than a threshold, and energizing the heater when the temperature detected by the internal sensor is equal to or higher than the driving temperature. An optical switch module comprising a control circuit for stopping the operation. 8. An optical switch module provided with the optical switch according to claim 2, wherein the optical switch module receives a drive signal for switching an optical path of the optical switch and measures the temperature of the optical switch. Circuit, a switching current supply unit for the optical fiber switching unit, and a heating current supply unit for the heater, wherein the control circuit turns on and off the switching current supply unit and turns on and off the heating current supply unit. An optical switch module characterized by the above-mentioned. 9. The optical switch module according to claim 8, further comprising a delay circuit that delays the supply of the switching current from the supply of the warm-up current. 10. The optical switch module according to claim 6, wherein a temperature inside or near the optical switch is within a predetermined temperature range, and a signal output or display is performed. An optical switch module comprising means for performing the operation. 11. The optical switch module according to claim 6, wherein a temperature inside or near the optical switch is detected, and when the temperature is not within a predetermined range, an optical switch switching signal. An optical switch module, comprising an interlock that does not receive a signal.