JP2001350105A - Optical switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems of a conventional 2×2 type optical switch that the parallelism and interval of the opposite surfaces of a diamond prism need to have high processing precision, the precision of the optical axis between collimators arranged opposite to each other should be extremely high, and the adjacent interval precision of the adjacently arranged collimators should also be made extremely high so as to reduce coupling loss with good reproducibility since the conventional optical switch switches an optical coupling state by using two states, that is, a state wherein one diamond prism is inserted between the collimators to be optically coupled and a state wherein the prism is not inserted and also to solve such a problem that the generation of PDL characteristics cannot be prevented in principle. SOLUTION: The optical switch is provided which switches the optical coupling state by using two states, that is, the state wherein two total reflecting prisms are inserted between the two collimators to be optically coupled and the state wherein they are not inserted. An optical switch of this configuration which has low coupling loss and good reproducibility and prevents PDL characteristics from being generated can be provided at a low price with good mass-productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical switch for switching an optical fiber transmission line in optical communication using an optical fiber as a transmission line. Hereinafter, unless otherwise specified, the optical fiber means a general-purpose optical fiber that is not a polarization maintaining fiber.

[0002]

2. Description of the Related Art In optical communication using an optical fiber for a transmission line, various optical switches have been devised as means for mechanically switching an optical signal on one optical fiber transmission line to another optical fiber transmission line. Has been put to practical use. Among these, the optical signal input to one of the two input ports is selectively coupled to an arbitrary output port, and the optical signal input to the other input port is similarly coupled to the above. There is an optical switch function that can be selectively coupled to an arbitrary output port, that is, a 2 × 2 optical switch function. That is, the 2 × 2 type optical switch causes optical coupling by mechanically arbitrarily switching an optical signal input to any one of the two input ports to any of the two output ports. Similarly, the optical signal light input to the other input port also has a function of being optically coupled to any of the two output ports and output.

An optical switch such as a conventional 2 × 2 type optical switch is disclosed in, for example, the document “Y-asuaki Ta”.
mura: "Single Mode Fiber W
DMin the 1.2 / 1.3 μm Wavele
Nthth Region ", Journal of L
lightwave Technology, Vol. L
T-4, no. 7, July, pp. 841-845 "
Is disclosed. Hereinafter, an outline of the configuration and the principle operation will be described with reference to FIG.

FIG. 6 is a view for explaining a conventional optical switch. FIG. 6A is a view showing a state where an optical path is in a bar state described later.
(B) is a diagram showing a state where the optical path is in a cross state described later.
In FIG. 6, reference numeral 600 denotes an optical switch,
8 is an optical fiber, 611 to 614 are lenses, 601 to 6
04 is a collimator composed of an optical fiber and a lens, 6
10 is a rhombic prism, 6101 to 6104 are surfaces of the rhombic prism 610, and 609 is a housing.

In FIG. 6A, as shown in the figure, a collimator 601 and a collimator 603 are provided to face each other to form an optical coupling, and at the same time, a collimator 602 and a collimator 604 are provided to face each other. A bond has been formed. And, the rhombic prism 610 is not inserted in the optical path. This optical coupling state is called a bar state.
In FIG. 6B, as shown in the figure, the rhombic prism 610 is in the state of being inserted into the optical path, and the light emitted from the collimator 601 changes its course by being refracted by the rhombic prism 610. , The collimator 604 is optically coupled to the collimator 604, and similarly, the light emitted from the collimator 602 is refracted by the prism 610, changes its course, and is incident on the collimator 603. Collimator 60
2 is optically coupled to the collimator 603. This optical coupling state is called a cross state. That is, the prism 6
The optical path can be switched by inserting or not inserting the optical path 10 into the optical path.

[0006]

However, in the above conventional 2 × 2 type optical switch, the collimator 60
1 and the collimator 603 and the collimator 602 and the collimator 604, respectively, must be mounted with extremely high precision in the angle formed by the optical axes of these two optically coupled beams. To 0.
In order to suppress the difference to 5 dB or less, the allowable angle error between the optical axes of the two optically coupled beams must be 0.05 degrees or less (from the optical coupling characteristics of FIG. 4 in the literature).

Similarly, the collimator 601 and the collimator 6
02 must also be mounted with high accuracy. For example, in order to suppress the coupling loss deterioration amount to 0.5 dB or less, it is necessary to set the allowable adjacent space accuracy to 55 μm or less ( (From FIG. 4 of the aforementioned document).

Further, the opposing parallel surfaces 6101 and 6104 and 6102 and 61 of the rhomboid prism 610
High precision processing is also required for the parallelism of 03 and the thickness accuracy of the prism. The reason why the coupling loss increases unless each of them is mounted and processed with high precision will be described below.

First, in the case of a bar state as shown in FIG. 6A, after the collimator 601 is fixed to the housing 609 first, the collimator 603 is opposed to the collimator 601 in a state where the collimator 603 is opposed to the collimator 601. It can be realized without any problems. Similarly, disposing the collimator 604 in opposition to the collimator 602 can be realized without any problem.

Next, when a rhombic prism 610 is inserted into a cross state on the optical path as shown in FIG.
The light emitted from the collimator 601 is
The light refracts at the first surface 6101 to change the optical path, reaches the surface 6104 of the rhombic prism 610, refracts again, and travels toward the collimator 604. At this time, in order for the position and angle of the optically coupled beam to be optically coupled to the collimator 604, the allowable deviation amount of the optical axis of the optically coupled beam must be equal to or less than the value described in the above description (for the rhombic prism 610). Face 61
The position and angle of the light emitted from the rhombic prism 6
(Depending on the distance between the opposing faces 6101 and 6104 and the angle between them)). Light emitted from the collimator 602 is refracted by the surface 6102 of the rhombic prism 610, reaches the surface 6103, is refracted again, and is collimated by the collimator 603.
Head for. The same applies to the relationship of the allowable deviation of the optical axis of the optically coupled beam at this time.

As described above, an optical switch having a configuration represented by a 2 × 2 type optical switch using a rhombic prism as shown by a rhombic prism 610 in FIG. In order to provide the same, surprisingly high precision is required for the opposing arrangement of the collimator and the processing accuracy of the rhombic prism, the manufacturing cost is high, the yield is low, and the quality is likely to be uneven.

Further, when the optical path is in a cross state, the light from the collimator 601 is applied to the surface 610 of the rhombic prism 610.
When the light is incident on 1, the incident angle is not 0 degree in principle, which means that, as is well known, the refracted light traveling inside the rhombic prism 610 varies its intensity depending on the polarization state of the incident light. . Then, this refracted light is converted into a rhombic prism 6.
The same applies to the case where the light is emitted from the surface 6104 of No. 10. That is, in optical coupling between the collimator 601 and the collimator 604, a PDL (polarization depen- dation) having a different coupling loss depending on the polarization state of the incident light.
It is impossible in principle to make the dent loss) characteristic zero. The collimator 602 and the collimator 6
The same applies to the optical coupling of No. 03, and such a conventional optical switch has a disadvantage that PDL characteristics occur in principle.

As described above, this conventional optical switch requires extremely high processing accuracy required for optical components and extremely high adjacent spacing accuracy required for mounting a collimator. This type of conventional optical switch has the drawbacks that not only the manufacturing cost is extremely high, but also that the quality varies greatly and that PDL characteristics, which is one of the important characteristics of the optical switch, occur.

The present invention has been made in view of the above points, and an object of the present invention is to eliminate the use of specially machined mechanical parts and optical parts and to reduce the mounting restrictions of the collimator. Even low loss coupling can be ensured,
An object of the present invention is to provide an optical switch that has good switching reproducibility and does not generate PDL characteristics at a high production yield and at low cost.

[0015]

In order to achieve the object of the present invention, in the example of the optical switch of the present invention, one side of a housing (also referred to as a case) (hereinafter, also referred to as side 1).
At least one collimator composed of a lens and an optical fiber (hereinafter, simply referred to as a collimator)
And one of a plurality of collimators arranged on a side surface (hereinafter, also referred to as a side surface 2) different from the side surface 1 of the housing.
An optical switch for optically coupling the two, wherein the optical switch has a movable pedestal equipped with at least two total reflection prisms, and by moving the movable pedestal,
The optical coupling between one collimator disposed on the side surface 1 and one of the plurality of collimators disposed on the side surface 2 is performed by using an optical path between the collimators among at least two total reflection prisms mounted on the movable pedestal. Optical coupling is performed by inserting two total reflection prisms, and the one collimator arranged on the side surface 1 and one collimator different from the one collimator among the plurality of collimators arranged on the side surface 2 are combined. The optical coupling is characterized in that the optical coupling is switched by a method of performing optical coupling by not inserting a total reflection prism mounted on the movable pedestal into an optical path between the collimators.

According to the embodiment of the present invention, the side surface 1
In addition, two collimators can be arranged on each of the side surfaces 2, and according to the example of the present invention, one collimator can be arranged on the side surface 1 and three collimators can be arranged on the side surface 2.

In the optical switch of the present invention, the total reflection prism is mounted on a support having at least a part of a spherical shape, for example, a hemispherical rigid body having a flat portion. The hemispherical rigid spherical surface is in line contact with one surface of a cylindrical object provided on the movable pedestal, for example, a cylindrical rigid body, and the hemispherical rigid body and the cylindrical shape The arrangement of the total reflection prism is adjusted by the rigid body, and the prism is mounted on the movable base. The total reflection prism is a right-angle prism having one total reflection surface and two surfaces acting as light transmission surfaces.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure used for the description has dimensions and dimensions of each component so that these inventions can be understood.
The shape, arrangement, and the like are schematically shown. In particular, the shape and size of each component may be partially enlarged or reduced as appropriate for convenience of explanation, and are not necessarily similar to the actual product. In addition, in each of the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

FIG. 1 is a diagram for explaining an optical switch of the present invention. FIG. 1A is a front view of an optical switch 100, and FIG.
FIG. 2B is a cross-sectional view of the optical switch 100 shown in FIG. FIG. 2 is a diagram for explaining an operation state of the optical switch 100 of FIG. 1, and FIG.
FIG. 2B is a diagram illustrating the operation of the optical switch 100 in the cross state, and FIG. 2B is a diagram illustrating the operation of the optical switch 100 in the bar state. 1 and FIG.
Reference numeral 00 denotes an optical switch, reference numerals 101 to 104 denote collimators each composed of an optical fiber and a lens in the same manner as described with reference to FIG. 6, reference numerals 105 to 108 denote right-angle prisms (hereinafter, also simply referred to as prisms), and reference numerals 1051 to 1053. 1061
-1063, 1071-1073, 1081-1083
Are the surfaces of the prisms 105, 106, 107 and 108, respectively, and 1111 to 1114 are the prisms 105 to 1 respectively.
08 has a flat surface, and the lower part is a hemispherical holder as a prism support, 1121 to 1124 are cylindrical holders, 120 is a movable pedestal, 130 is a housing, 131 and 132 are side surfaces of the housing 130, 140 Is a dashed line showing a cross-sectional portion of the cross-sectional view of FIG. 2 (B), 150 is an arrow showing a moving direction of the movable base 120, 201 to 208 are dashed lines showing an optical path,
Arrows 211 to 213 indicate the directions of the coordinate axes.

In FIG. 1, collimators 101, 102
Is fixed to the side surface 131 of the housing 130, and the collimators 103 and 104 are the side surfaces 13 of the housing 130 opposite to the side where the collimators 101 and 102 are fixed.
It is fixed to 2. Collimator 101 and collimator 1
03, and the collimator 102 and the collimator 104 are linearly opposed to each other, and the prisms 105 to 108
Is in a state where the optical path between the linearly opposed collimators is not blocked, an optical coupling type is formed between the linearly opposed collimators. A movable pedestal 120 is provided at the center of the housing 130. As shown in FIG. 1B, a cylindrical holder 1121 is fixed to the movable pedestal 120, and the cylindrical holder 1121 has a hemispherical holder. 1111 is fixed, and the prism 105 is fixed to the hemispherical holder 1111. Similarly, the cylindrical holder 112 is attached to the movable base 120.
2 to 1124 are fixed, and the cylindrical holder 112 is fixed.
2 to 1124 are hemispherical holders 1112 to 111, respectively.
4 are fixed, and the hemispherical holders 1112 to 111
4, prisms 106 to 108 are respectively fixed. The prisms 105 to 108, the hemispherical holders 1111 to 1114, and the cylindrical holders 1121 to 1
In the case where the movable base 124 and the movable pedestal 120 are fixed by, for example, an adhesive or a YAG laser, the angles and positions of the prisms 105 to 108 with respect to the movable pedestal 120 can be freely adjusted before fixing. It is possible to maintain low-loss coupling without using precision machined mechanical parts and optical parts and relaxing the mounting limit of the collimator. Further, the movable pedestal 120 can move linearly in the direction shown by the arrow 150, and the prisms 105 to 108 fixed on the movable pedestal 120 move in the direction shown by the arrow 150 while maintaining their relative positions to each other. It can move linearly. The prisms 105 to 108 constitute two split-type optical path changing prisms each including the prisms 105 and 108 and 106 and 107 as a pair.

The prisms 105 to 108, the hemispherical holders 1111 to 1114, and the cylindrical holder 112
1 to 1124 and the movable pedestal 120 can be fixed with an adjusting function so that the position of the prisms 105 to 108 in the optical path can be adjusted as necessary, and therefore, low loss coupling and high reliability can be achieved. An optical switch having a characteristic can be realized at low cost.

The operation of the optical switch 100 will be described below with reference to FIG.

When the optical switch 100 is in the cross state, the light emitted from the collimator 101 passes through the optical path indicated by the broken line 201 and passes through the prism 10 as shown in FIG.
5 enters the prism 105 from the surface 1051, and the surface 1
The light is totally reflected at 052 and the optical path is changed as shown by a broken line 202, and the light is emitted from the surface 1053 and travels to the prism 108. Then, the light enters the prism 108 from the surface 1081 of the prism 108, is totally reflected by the surface 1082, and
The optical path is changed as indicated by 03 and emitted from the surface 1083 and coupled to the collimator 104. At this time, the surface 105
1, 1081, the angle at which light is incident and the surfaces 1053, 1
Since the angle at which light is emitted from 083 can be almost 0 degrees, optical coupling can be performed without deteriorating PDL characteristics at the interface between the prisms 105 and 108. Furthermore, since the reflection of light on the surfaces 1052 and 1082 utilizes the total reflection effect, the light reflection loss at that portion is extremely small. Here, the prism 105
The positions and angles of the prism 108 are mounted and fixed so that optical coupling between the collimator 101 and the collimator 104 is formed. The positions and angles of the prism 105 and the prism 108 can be adjusted with high accuracy and easily as described with reference to FIG. Similarly, the light emitted from the collimator 102 passes through the optical path indicated by the broken line 204, enters the prism 106 from the surface 1061 of the prism 106,
The light is totally reflected by the surface 1062 and changes its optical path as indicated by a broken line 205, and is emitted from the surface 1063 toward the prism 107. Then, the light enters the prism 107 from the surface 1071 of the prism 107, is totally reflected by the surface 1072, changes the optical path as shown by a broken line 206, is emitted from the surface 1073, and is coupled to the collimator 103 (FIG. 1A). reference). Further, the prism 106 and the prism 1
07 are located in the collimator 102
And the collimator 103 are mounted and fixed so as to form an optical coupling with the collimator 103.

When the optical switch 100 is in a bar state, as shown in FIG.
The movable pedestal 120 on which is fixed the arrow 150 (FIG. 1).
(A), the prisms 105 to 108 move out of the optical path indicated by broken lines 207 and 208, and the light emitted from the collimator 101 Similarly, the light emitted from the collimator 102 passes through the optical path indicated by a broken line 208 and is coupled to the collimator 104 via the optical path indicated by 207.

Next, the movable base 1 of the optical switch 100
20, on the angles of the prisms 105-108,
A case where the position is adjusted will be described with reference to FIGS. 2, 3, and 4. FIG. 3 and 4 are views for explaining optical coupling when the movable pedestal of the present invention is mechanically displaced.
1, 302, 401 and 402 are collimators, 303 and 3
04, 403, 404 are right angle prisms, 3031 to 30
33 is the surface of the prism 303, 3041 to 3043 are the surfaces of the prism 304, 4031 and 4033 are the prisms 403
Surface 4042 is the surface of the prism 404, 310, 410
Is a movable pedestal, 311, 313 to 316, 411, 413
Reference numerals 416 denote arrows indicating the directions of the coordinate axes.

As shown in FIG. 2A, the collimator 10
1 passes through an optical path indicated by a broken line 201 and passes from the surface 1051 of the prism 105 to the prism 10.
5, the light is totally reflected by the surface 1052, the optical path is changed as indicated by a broken line 202, and the light exits from the surface 1053 and travels to the prism 108. At this time, the collimator 10
By moving the position and angle of the prism 105 while keeping the angle and position of the light emitted from 1 constant, that is, by moving the position and angle of the surface 1052 and the like, the arrow 2
Except for the adjustment in the z-axis direction indicated by 13, that is, the height direction of the light emitted from the prism 105, the angle and position of the emitted light can be freely changed. Then, the emitted light is transmitted from the surface 1081 of the prism 108 to the prism 10.
8, the light is totally reflected by the surface 1082, the optical path is changed as indicated by a broken line 203, and the light exits from the surface 1083 and is coupled to the collimator 104. At this time, the prism 10
Similarly to 5, the position and angle of the prism 108 are moved, that is, the position and angle of the surface 1052 and the like are moved to adjust the z-axis direction indicated by the arrow 213, that is, the height direction of the light emitted from the prism 108. Except for the above, the angle and position of the emitted light can be freely changed.

The following describes that optical coupling is performed between the collimator 101 and the collimator 104 in such a system. In other words, the direction and position of the light emitted from the collimator 101 are fixed, so that the light incident on the collimator 104 can be adjusted to any angle and any position.

The angle adjustment in the plane parallel to the plane of the optical path 203 can be performed by rotating the prism 105 or the prism 108 around the z-axis. This is made possible by rotating 108 around the y-axis. The position of the optical path 203 in a plane parallel to the plane of the paper can be adjusted by adjusting the position of the prism 108 parallel to the plane of the paper. The position of the optical path 203 in a plane perpendicular to the plane of the paper can be adjusted by rotating the prism 105 around the x-axis. Thus, all degrees of freedom can be given to the angle and the position of the light emitted from the prism 108.

That is, by using two right-angle prisms in combination, even if the position and angle of the collimator 104 are arbitrary, optical coupling becomes possible. The same applies to the relationship between the collimator 102 and the collimator 103.

Next, a description will be given of the fact that optical coupling is stable even if mechanical imperfections occur due to the movement of the movable pedestal.

As shown in FIG. 3, the prism 30 is formed by the above method.
The movable pedestal 310 in which 3 and 304 are adjusted is indicated by an arrow 315.
When rotated about the z axis indicated by
The light emitted from the prism 303 enters the prism 303 from the surface 3031 of the prism 303, is totally reflected by the surface 3032, is emitted from the surface 3033, goes to the prism 304, and enters the prism 304 from the surface 3041 of the prism 304. Are reflected from the surface 3042 and are emitted from the surface 3043, and the position of the output optical axis is shifted by Δx as shown by an arrow 316. The angle of the output optical axis is different from the angle of reflection at the surface 3032 and the angle at the surface 3042. The reflection angle can be coupled to the collimator 302 without changing by changing the optical axis angle.

Similarly, when the movable pedestal 410 in which the prisms 403 and 404 are adjusted by the above method as shown in FIG. 4 is rotated around the z-axis indicated by the arrow 415, the light emitted from the collimator 401 is 403 face 40
31 enters the prism 403, is totally reflected by the surface 4032, exits from the surface 4033, goes to the prism 404, enters the prism 404 from the surface 4041 of the prism 404, is totally reflected by the surface 4042, and is completely reflected by the surface 4043. And the position of the outgoing optical axis is shifted by Δz as shown by an arrow 416, but the outgoing optical axis angle cancels the optical axis angle change due to the reflection angle at the surface 4032 and the reflection angle at the surface 4042. Collimator 4 without changing
02. That is, although a slight displacement occurs, no angular displacement occurs.

As is well known, in an optical coupling system formed by opposing collimators, the optical coupling loss largely depends on the optical axis angle shift, and is insensitive to the optical axis position shift. In the optical switch of the present invention, the optical axis angle, which has a large effect on optical coupling loss, is always kept constant with respect to any mechanical displacement of the movable pedestal. It can be kept in the wrong position.

As described above, the prisms 105-1
By changing the position of the movable base 120 to which 08 is fixed, it is possible to switch between the bar state and the cross state of the optical coupling as the 2 × 2 type optical switch. And
When the prisms 105 to 108 are fixed to the movable pedestal 120, the angles and positions of the prisms 105 to 108 with respect to the movable pedestal 120 can be freely adjusted before the fixing, and light that greatly affects optical coupling loss can be adjusted. The shaft is less likely to be misaligned, and low-loss coupling can be maintained without using specially machined machine parts and optical parts that have been machined with high precision, and even when mounting restrictions on the collimator are relaxed.

[0035]

Next, the present invention will be described in more detail with reference to examples.

FIG. 5 is a view for explaining an embodiment of the present invention. FIG. 5A shows a collimator 501 (described later) and a collimator 5.
FIG. 4B illustrates a state of coupling with a collimator 501 and a collimator 503 (described later), and FIG. 3C illustrates a state of coupling with a collimator 501 and a collimator 503 (described later).
It is a figure which shows the connection state with (described later). In FIG.
Reference numerals 501, 503, 504, and 505 are collimators,
06 to 509 are prisms, 5061 to 5063 and 507
1 to 5073, 5081 to 5083, 5091 to 509
3 is the surface of the prisms 506, 507, 508, 509, 5
111 to 5114 are hemispherical holders, 5121 to 5124 are cylindrical holders, 520 is a movable pedestal, 530 is a housing, 53
Reference numerals 1 and 532 denote side surfaces of the housing 530, and 515 denotes a movable base 52.
Arrows indicating movement directions of 0, 551 to 553, 560, and 5
Reference numerals 71 to 573 denote broken lines indicating the course of light emitted from the collimator 501. The prisms 506 to 509 are right angle prisms and total reflection prisms.

When the collimator 501 and the collimator 504 are optically coupled, as shown in FIG.
06 and the prism 507 are inserted into the optical path between the collimator 501 and the collimator 504, and the light emitted from the collimator 501 passes through the optical path indicated by the broken line 551 and enters the prism 506 from the surface 5061 of the prism 506,
The light is totally reflected by the surface 5062 and changes its optical path as indicated by a broken line 552, and is emitted from the surface 5063 and travels to the prism 507. Then, the light enters the prism 507 from the surface 5071 of the prism 507, is totally reflected by the surface 5072, changes the optical path as shown by a broken line 553, is emitted from the surface 5073, and is coupled to the collimator 504. The position and angle of each of the prism 506 and the prism 507 are determined by the prism 506 and the prism 507.
Is mounted and fixed so that when the light is inserted into the optical path between the collimator 501 and the collimator 504, optical coupling between the collimator 501 and the collimator 504 is formed.

The collimator 501 and the collimator 50
3 is optically coupled, as shown in FIG. 5B, the movable base 520 to which the prisms 506 to 509 are fixed.
Is moved in one of the directions indicated by the arrow 515, the prism 506 moves from the optical path indicated by the broken line 551, and the light emitted from the collimator 501 passes through the optical path indicated by the broken line 560 and passes through the collimator 503. To join.

Then, the collimator 501 and the collimator 5
5 is optically coupled, the prism 508 and the prism 509 are inserted into the optical path as shown in FIG. 5C, and the light emitted from the collimator 501 passes through the optical path indicated by the broken line 571 and the surface 5081 of the prism 508. Enters the prism 508, and is totally reflected by the surface 5082 and is indicated by a broken line 572.
The light path is changed as shown by, and the light is emitted from the surface 5083 and goes to the prism 509. And the prism 509
Enters the prism 509 from the surface 5091 of the
The light is totally reflected at 92 and the optical path is changed as shown by a broken line 573, emitted from the surface 5093, and optically coupled to the collimator 505. The position and angle of each of the prism 508 and the prism 509 are different from those of the prism 508.
And the prism 509 and the collimator 501 and the collimator 50
5 is mounted and fixed so that when it is inserted into the optical path between the collimators 5 and 5, the optical coupling between the collimator 501 and the collimator 505 is formed.

As described above, the optical switch of the present invention can be applied to an optical switch suitable for various uses based on a 2 × 2 type optical switch.

The optical switch 100 described with reference to FIG.
The prisms 105 to 108 are made of BK-7 glass (refractive index 1.5), and the surfaces 105 of the prisms 105 to 108 are
1, 1053, 1061, 1063, 1071, 107
3, 1081 and 1083 to AR (Anti-Refle
ction) A coating process is performed, and the collimators 101 to 1
When the optical fiber used for the optical fiber 04 was manufactured as a single mode fiber and the measurement wavelength was measured at 1.55 μm, the coupling loss in the optical coupling from the collimator 101 to the collimator 103 was 0.30 dB, and the PDL was 0.01 d.
B or less, switching reproducibility is 0.01 dB or less, coupling loss in optical coupling from the collimator 101 to the collimator 104 is 0.29 dB, PDL is 0.01 dB or less, and switching reproducibility is 0.01 dB or less. The coupling loss in optical coupling from 102 to the collimator 103 is 0.37 dB, the PDL is 0.01 dB or less, the switching reproducibility is 0.01 dB or less, and the collimator 1
The coupling loss in the optical coupling from 02 to the collimator 104 was 0.37 dB, the PDL was 0.02 dB or less, and the switching reproducibility was 0.01 dB or less.

Further, depending on the type of the optical switch used conventionally, when a polarization maintaining fiber is used as the optical fiber, conditions such as extremely high precision are required to improve the optical coupling characteristics. However, according to the present invention, even when a polarization maintaining fiber is used as the optical fiber, the same effect as that of the general-purpose optical fiber described above is exerted.

[0043]

As described above, the present invention has been described in detail. In the optical switch of the present invention, an optimum optical coupling system can be obtained only by appropriately adjusting the angles and positions of at least two total reflection prisms. Therefore, it is possible to provide an optical switch with low loss, easy operation, and high reliability at a high production yield and at a low cost, without requiring special high precision in the processing of the prism and the mounting position of the collimator. Since the prism used in the optical switch of the present invention is a total reflection prism, loss of light upon incidence and reflection on the prism is extremely small, and switching can be performed without substantially deteriorating PDL characteristics. I can do it. In addition, even for mechanical instability of the movable pedestal due to the movement of the movable pedestal (for example, angle play and displacement play), the optical coupling loss switching does not occur, so the optical coupling type switching is reproduced. It is possible to provide an optical switch having stable characteristics and high durability.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an optical switch of the present invention;
(A) is a front view, (B) is a sectional view.

2A and 2B are diagrams illustrating an operation state of the optical switch according to the present invention, wherein FIG. 2A is a diagram illustrating a C-loss state, and FIG. 2B is a diagram illustrating a bar state.

FIG. 3 is a diagram illustrating optical coupling of the optical switch according to the present invention.

FIG. 4 is a diagram illustrating optical coupling of the optical switch according to the present invention.

5A and 5B are diagrams illustrating an embodiment of the present invention, and FIG. 5A is a diagram illustrating a coupling state between collimators 501 and 504;
(B) is a diagram showing a coupling state of the collimators 501 and 503, and (C) is a diagram showing a coupling state of the collimators 501 and 505.

FIG. 6 is a diagram illustrating a conventional optical switch, and FIG.
FIG. 4B is a diagram illustrating a state where the optical path is in a bar state, and FIG. 4B is a diagram illustrating a case where the optical path is in a cross state.

[Explanation of symbols]

100, 600: optical switches 101 to 104, 301, 302, 401, 402, 5
01, 503, 504, 505, 601 to 604: Collimators 105 to 108, 303, 304, 403, 404, 5
06 to 509: right angle prisms 1051 to 1053, 1061 to 1063, 1071
1073, 1081 to 1083, 3031 to 3033,
3041 to 3043, 4031, 4033, 4042,
5061 to 5063, 5071 to 5073, 5081 to
5083, 5091 to 5093, 6101 to 6104:
Surfaces 1111 to 1114, 5111 to 5114: hemispherical holders 1121 to 1124, 5121 to 5124: cylindrical holders 120, 310, 410, 520: movable pedestals 130, 530, 609: housings 131, 132, 531 and 532: housings Sides 140, 201-208, 551-553, 560, 5
71 to 573: broken lines 150, 211 to 213, 311, 313 to 316, 4
11, 413 to 416, 515: arrows 605 to 608: optical fiber 611 to 614: lens 610: rhombic prism

Claims (7)

[Claims] At least one collimator (hereinafter, simply referred to as a collimator) composed of a lens and an optical fiber disposed on one side surface (hereinafter, also referred to as a side surface 1) of the housing, and An optical switch for optically coupling any one of a plurality of collimators arranged on a side surface (hereinafter, also referred to as a side surface 2) different from the side surface 1, wherein the optical switch includes at least two total reflection prisms. Having a movable pedestal mounted thereon, by moving the movable pedestal, optical coupling between one collimator disposed on the side surface 1 and one of the plurality of collimators disposed on the side surface 2 is performed on an optical path between the collimators. The optical coupling is performed by inserting two total reflection prisms of at least two total reflection prisms mounted on the movable pedestal, and the 1 is disposed on the side surface 1. Optical coupling between one collimator and the other collimator different from the one collimator among the plurality of collimators arranged on the side surface 2 is performed by inserting a total reflection prism mounted on the movable base into an optical path between the collimators. An optical switch characterized in that the optical coupling relationship is switched by a method of optical coupling by not performing. 2. The optical switch according to claim 1, wherein
Two collimators are arranged on each of the side surface 1 and the side surface 2, and the movable pedestal has four total reflection prisms. By moving the movable pedestal,
One of the two collimators arranged on the side surface 1 (hereinafter, referred to as a first collimator in the present invention) and one of the two collimators arranged on the side surface 2 (hereinafter, referred to as a first collimator) And a fourth collimator in the claims) and the side surface 1
The other collimator of the two collimators (hereinafter, also referred to as a second collimator in the present invention) and the other collimator of the two collimators arranged on the side surface 2 (hereinafter, referred to as a second collimator) The optical coupling with the third collimator in the claims is performed by inserting two total reflection prisms of four total reflection prisms mounted on the movable base into respective optical paths between the collimators. The optical coupling between the first collimator and the third collimator and the optical coupling between the second collimator and the fourth collimator are mounted on the movable pedestal in an optical path between the collimators. An optical switch characterized in that the optical coupling relationship is switched by a method of performing optical coupling by not inserting a total reflection prism. 3. The optical switch according to claim 1, wherein
One collimator is disposed on the side surface 1 and three collimators are disposed on the side surface 2, and the movable pedestal is equipped with four total reflection prisms, and the movable pedestal is moved to move the movable pedestal. Light of one collimator (hereinafter, referred to as a first collimator in the present invention) and one of the three collimators disposed on the side surface 2 (hereinafter, referred to as a third collimator in the present invention) Coupling, and one of the three collimators arranged on the side surface 2 different from the third collimator (hereinafter, referred to as a fourth collimator in the present invention)
Optical coupling is performed by inserting any two total reflection prisms of the four total reflection prisms mounted on the movable pedestal into the respective optical paths between the respective collimators, and performing the optical coupling. The first and second collimators arranged on the side surface 2 and the third and fourth collimators out of the three collimators are optically coupled to each other by an optical path between the collimators. An optical switch, wherein an optical coupling relationship is switched by a method of performing optical coupling by not inserting a total reflection prism mounted on a movable base. 4. The optical switch according to claim 1, wherein at least one of said total reflection prisms is provided.
One of which is mounted on a support having at least a part of a spherical shape, and a part of the rigid spherical portion of the support is in line with one surface of a cylindrical object provided on the movable pedestal. An optical switch characterized by being in contact. 5. The optical switch according to claim 1, further comprising a rail on which the movable pedestal can move linearly. 6. The optical switch according to claim 1, wherein the total reflection prism has a right angle having one total reflection surface and two surfaces acting as light transmission surfaces. An optical switch characterized by being a prism. 7. The optical switch according to claim 1, wherein the optical fiber forming the collimator is a polarization maintaining fiber.