JP2003262822A - Arraying intervals transformation optical system of two-dimensionally arrayed light beams - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transform the arraying intervals of two-dimensionally arrayed light beams in a specific direction in a simple composition. <P>SOLUTION: Wedge-shaped prisms 104 and 105 are arrayed with an interval so as to be inserted into an optical path. The light beams intervals of a light beam group of 102 outputted from an optical fiber array 101 are S<SB>fiber-</SB>X, the light beam group 102 is deflected only in an X-axis direction by passing through the wedge-shaped prisms 104 and 105. Further, the light beam group 102 is not deflected in a Y-axis direction even when passing through the wedge-shaped prisms 104 and 105. It means that the arraying directions of the wedge-shaped prisms 104 and 105 are so set that the light beam group 102 is deflected in the X-axis direction but not deflected in the Y-axis direction. The arraying intervals in the X-axis direction of the light beam group 102 deflected in the X-axis direction are transformed into S<SB>mirror-</SB>X on a reference plane R. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensionally arranged optical beam array spacing conversion optical system, which is useful when applied to an input / output section of an optical switch used in optical communication.

[0002]

2. Description of the Related Art Due to the rapid increase in data traffic represented by stream data such as WWWeb and video, it is required to increase the capacity of a backbone network constituting the Internet. 10Gbit for network transmission line
High-speed and large-capacity optical communication equipment that exceeds / s, and WDM (wevelength division multiple) that realizes even larger capacity by multiplexing optical signals of different wavelengths on the same optical fiber.
xing) An optical communication device has been introduced.

However, in the node portion, a method is used in which an optical signal is once converted into an electric signal, the path is switched by a switch using a conventional electric circuit, and then converted into an optical signal again to be returned to the network. Is common. It has been pointed out that the cost and power consumption of the device shown here for converting an electrical signal to an optical signal or from an optical signal to an electrical signal increase significantly as the signal band is improved.

Therefore, especially when the signal speed reaches 40 Gbit / s, it is considered effective to use an optical switch for switching an optical signal as it is. Among them, the free space type optical switch using the high-density three-dimensional wiring using the light beam can configure a large-scale optical switch with more than 1000 terminals compactly. Is expected to be introduced.

7 and 8 show a conventional example of a free space type optical switch (T. Yeow, et al, IEEE Communication Ma.
gazine, pp, 158-163, Nov. 2001). In both figures, 1 is an input optical fiber array, 2 is a collimating microlens array,
3 is a light beam, 4 and 5 are micro movable mirror arrays, 6 is a condenser microlens array, and 7 is an output optical fiber array.

The optical fiber arrays 1 and 7 are composed of a plurality of optical fibers arranged two-dimensionally, the microlens arrays 2 and 6 are composed of a plurality of microlenses arranged two-dimensionally, and a micro movable mirror. Array 4,
Reference numeral 5 is composed of a plurality of micro movable mirrors arranged two-dimensionally. The arrow indicates the traveling direction of the light beam.

The micro movable mirror arrays 4 and 5 are active elements formed on a semiconductor substrate by using a micromachining technique, and adjust the tilts of the mirror surfaces in the rotation directions about the X axis and the Y axis, respectively. it can. The two semiconductor substrate surfaces on which the mirrors are formed are respectively inclined by θ [deg.] About the Y axis as the center of rotation as shown in the figure.

Next, the operation of the optical switch will be described with reference to FIG. The light beam 3 emitted from the input optical fiber array 1 is converted into parallel light (light beam 3) by the collimating microlens array 2 and reaches the micro movable mirror array 4. The light beam 3 travels in the direction indicated by the broken line when the mirror surface of the micro movable mirror array 4 is in parallel with the semiconductor substrate, and the mirror surface has δ [deg. If it is inclined, proceed in the direction indicated by the solid line. Each of the light beams 3 reflected by the micro movable mirror array 4 reaches the other micro movable mirror array 5, is reflected by the mirror of the micro movable mirror array 5, and then the condensing micro lens array 6 is passed through. It is then guided to the output optical fiber array 7.

As described above, by appropriately adjusting the angle of the mirror surface with the Y axis as the center of rotation, it is possible to connect the arbitrary input / output optical fiber arrays 1 and 7 arranged on the X axis.

On the other hand, if the angle of the mirror surface is adjusted with the X axis as the center of rotation, any optical fibers arranged on the Y axis can be connected by the same action, so that the mirror surface of the mirror surface with both the XY axes as the center of rotation. By adjusting the angle, it is possible to connect arbitrary input and output optical fibers that are two-dimensionally arranged.

Generally, the volume of the two-dimensional optical fiber arrays 1 and 7 is larger than that of other optical parts such as the microlens arrays 2 and 6 and the micro movable mirror arrays 4 and 5, and the arrangement of the optical fibers. Interference between optical components occurs, and it is not very realistic to realize the component layout shown in FIGS. 7 and 8.

Therefore, a method of arranging the corner cube mirror in the optical path and avoiding interference between the optical components is effective. FIG. 9 shows a side view of a free space type optical switch having a corner cube mirror in the input / output section. In FIG. 9, 11 is an input optical fiber array, 12 is a collimating microlens array, 13 and 18 are corner cube mirrors, 14 and 19 are reflection mirrors, 15 is a light beam, 16 and 17 are micro movable mirror arrays, and 20 is A condenser microlens array 21 is an output optical fiber array. The corner cube mirrors 13 and 18 have a vertical angle φ
The reflection mirrors 14 and 19 using a metal or dielectric multilayer film are formed on the hypotenuse of a prism having [deg.].

Here, the optical signal emitted from the input optical fiber array 11 changes its traveling direction obliquely to the upper right by the corner cube mirror 14, is reflected by the micro movable mirror array 16 and travels downward, and then moves to the micro. It is guided to the output optical fiber array 21 via the movable mirror array 17 and the corner cube mirror 18.

In the optical switch shown in FIG. 9, similar to the optical switches shown in FIGS. 7 and 8, the angles of the mirror surfaces of the micro movable mirror arrays 16 and 17 are adjusted with the XY axes as the centers of rotation. As a result, it is possible to connect the two-dimensionally arranged arbitrary input / output optical fiber arrays 11 and 21.

[0015]

In the conventional optical switch shown in FIGS. 7 and 8, the fiber array intervals in the X-axis direction and the Y-axis direction in the input / output optical fiber arrays 1 and 7 are S _fiber-X , S. _{fi ber-Y} and the mirror arrangement intervals in the X-axis direction and the Y-axis direction in the micro movable mirror arrays 4 and 5 are S _mirror-X and S _mirror-Y , where the fiber intervals of the respective axes are equal (S _fiber-X = S _fiber-Y = S
_fiber ), it is necessary to satisfy the relationship of S _mirror-X = S _fiber / cos θ S _mirror-Y = S _{fiber in} order to guide each light beam to the center of the corresponding mirror. Accordingly, when the inclination θ of the mirror substrate surface is other than 0 [deg.], The mirror spacing S of each axis in the micro movable mirror arrays 4 and 5 is S.
There is a gap between _mirror-X and S _mirror-Y .

In general, providing an optical fiber array or a semiconductor element array with irregular array intervals not only causes an increase in manufacturing cost, but also the inclination θ of the mirror array substrate depends on the operating characteristics of the micro movable mirror and the switch optical system. Since it changes depending on the layout, it is necessary to separately provide a mechanism for converting the arrangement interval of the light beams in the optical system.

In the structure of the conventional optical switch shown in FIG. 9 as well as in the case of FIGS. 7 and 8, not only a mechanism for converting the arrangement interval of the light beams 15 is required, but also 45 [deg. .], The corner cube mirrors 13 and 18 having the apex angle φ are not versatile, and it is difficult to reduce the manufacturing cost.

The present invention has been made in view of the above-mentioned prior art, and an object thereof is an optical system for converting the arrangement intervals of the two-dimensionally arranged light beams by focusing on a certain direction. To provide. In addition, due to the layout of the optical components, even if a corner cube mirror is inserted in the optical path, it has a high versatility of 45 [de].
g.] is provided in combination with a corner cube mirror to convert the array spacing of two-dimensionally arrayed light beams by focusing on a certain direction.

[0019]

The structure of the present invention for solving the above-mentioned problems is formed by arranging a plurality of wedge-shaped prisms at intervals, and the wedge-shaped prisms at the front stage are two-dimensionally arranged. A group of light beams that have been made incident,
The remaining wedge-shaped prisms are arranged at the positions where the light beam group deflected by the wedge-shaped prism immediately before the wedge-shaped prism is incident, and each wedge-shaped prism is one of the two-dimensional arrays. The light beam group is deflected in one one-dimensional direction, but is arranged in a direction in which the light beam group is not deflected in the other one-dimensional direction of the two-dimensional array. Further, two sets of optical-beam array spacing conversion optical systems configured in this manner are arranged, and furthermore, the array-space conversion of the first set of optical beams when viewed from the start end to the center of the optical path. The shape and arrangement direction of each wedge prism that constitutes the optical system, and when viewed from the end of the optical path toward the center,
It is characterized in that the shape and arrangement direction of each of the wedge-shaped prisms constituting the array-space conversion optical system of the second set of light beams are made to coincide with each other.

Further, the structure of the present invention is formed by arranging a plurality of prisms, which are a right-angled prism and a wedge-shaped prism, at intervals, and the two-dimensionally arranged light beam group is formed in the frontmost prism. While being incident, the remaining prisms are arranged at positions where the light beam group deflected by the prism immediately before the prism is incident, and
Each prism is arranged in a direction that deflects the light beam group in one one-dimensional direction of the two-dimensional array but does not deflect the light beam group in the other one-dimensional direction of the two-dimensional array. It is characterized by being Further, two sets of optical-beam array spacing conversion optical systems configured in this manner are arranged, and furthermore, the array-space conversion of the first set of optical beams when viewed from the start end to the center of the optical path. The shape and orientation of each prism that makes up the optical system, and when viewed from the end to the center of the optical path,
It is characterized in that the shapes and the orientations of the respective prisms constituting the array-interval converting optical system of the second set of light beams are matched.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

<First Embodiment> FIGS. 1 and 2 show an array spacing conversion optical system for two-dimensionally arrayed light beams according to a first embodiment of the present invention. As shown in both figures, the optical fiber array 101 has a large number of optical fibers arranged two-dimensionally, and the distance between the optical fibers is S _{fiber-x in} the X-axis direction (see FIG. 1). , Y
In the axial direction, the distance between the optical fibers is S _fiber-Y (see FIG. 2). The two-dimensionally arrayed light beam group 102 emitted from the optical fiber array 101 passes through the collimating lens array 103 and becomes parallel light.

The wedge prisms 104 and 105 have an apex angle of φ [deg.] And are made of glass or a polymer material. The wedge-shaped prisms 104 and the wedge-shaped prisms 105 are arranged at intervals.

The wedge-shaped prism 104 at the frontmost stage is arranged at a position where the two-dimensionally arrayed light beam group 102 that has become parallel light is incident, and the remaining wedge-shaped prism 1
Reference numeral 05 is arranged at a position where the light beam group 102 deflected by the wedge prism 104 immediately before is incident.
In addition, the wedge prisms 104 and 105 deflect the light beam group 102 in the X-axis direction as shown in FIG. 1, but do not deflect the light beam group 102 in the Y-axis direction as shown in FIG. It is located in. That is, the light-incident surfaces of the wedge-shaped prisms 104 and 105 have constant angles θ ₁ [deg.] And θ _{2 with} respect to the input and output optical axes.
It is arranged so that it becomes [deg.].

The light beam group 102 emitted from the optical fiber array 101 and collimated by the collimating lens array 103 is bent (deflected) by passing through the wedge prism 104, and is further wedge wedge prism 105.
Is bent (deflected) and is incident on the reference surface R.

The distance between the light beams in the X-axis direction on the reference plane R is S _mirror-X , which is different from the distance S _fiber-X before incidence on the prism (see FIG. 1). However, the distance S _mirror-Y between the light beams in the Y-axis direction on the reference plane R is the distance S _fiber-Y before the incidence on the prism.
(See Figure 2). After all, the conversion action of the light beam interval on the reference plane R is as shown in FIG.
It occurs only in the axial direction and does not occur in the Y-axis direction as shown in FIG. That is, it is possible to convert the arrangement intervals of the light beams by focusing on a certain direction.

The distance S _mirror-X between the light beams in the X-axis direction on the reference plane R is determined by the wedge prism 104,
The angle changes depending on the apex angle φ of 105 and the arrangement angle (direction of arrangement) of both prisms with respect to the input and output optical axes.

Next, the operation of the array spacing conversion optical system according to the first embodiment will be described. FIG. 3 shows that the wedge-shaped prisms 104 and 105 have an apex angle φ of 29.5 [deg.],
When the material of the wedge prisms 104 and 105 is SF11, the arrangement angle θ ₁ of the wedge prism 104 at the front stage obtained by using the ray tracing method and the input / output light beam interval ratio S _mirror-X on the X axis. _Shows the relationship with / S _fiber-X . Here, the arrangement angle θ ₂ of the other wedge prism 105 is separately adjusted so that the optical axis of the input light beam and the optical axis of the output light beam are parallel to each other.
From this result, it is understood that the spacing S _mirror-X between the light beams on the reference plane R can be continuously changed by changing the arrangement angle of the wedge prism 104. .

Although the two wedge prisms 104 and 105 are used in FIGS. 1 and 2, three or more wedge prisms may be arranged. In this case, the arrangement of the plurality of wedge-shaped prisms should satisfy the following condition. The two-dimensionally arranged light beam group is incident on the wedge-shaped prism at the frontmost stage, and the light beam group deflected by the wedge-shaped prism immediately before the wedge-shaped prism is incident on the remaining wedge-shaped prisms. It is located in a position. Each wedge-shaped prism deflects the light beam group with respect to one one-dimensional direction (for example, the X-axis direction) of the two-dimensional array, but the other one-dimensional direction (for example, the Y-axis direction) of the two-dimensional array. ) Is arranged so as not to deflect the light beam group.

<Second Embodiment> Next, the second embodiment of the present invention will be described.
The array spacing conversion optical system for two-dimensionally arrayed light beams according to the above embodiment will be described with reference to FIG. As shown in FIG. 4, the optical fiber array 201 has a large number of optical fibers arranged two-dimensionally, and the distance between the optical fibers in the X-axis direction is S _fiber-x , and in the Y-axis direction. With respect to, the distance between the optical fibers is S _fiber-Y . The two-dimensionally arrayed light beam group 202 emitted from the optical fiber array 201 passes through the collimating lens array 203 and becomes parallel light.

The wedge prism 204 has an apex angle of φ [de
g.] and the right angle prism 205 has an apex angle of 45.
It is [deg.]. Both prisms 204 and 205 are
It is made of glass or polymer material. Further, a reflection mirror 206 made of a metal or dielectric multilayer film is formed on the inclined surface of the rectangular prism 205. The wedge prisms 204 and the right-angled prisms 205 are arranged at intervals T _i .

The wedge-shaped prism 204 at the frontmost stage is arranged at a position where the two-dimensionally arrayed light beam group 202, which is parallel light, is incident, and the right-angled prism 205 is the wedge-shaped prism 204 immediately before. It is arranged at a position where the deflected light beam group 202 is incident. Moreover, both prisms 204 and 205 are arranged in a direction that deflects the light beam group 202 in the X-axis direction but does not deflect the light beam group 202 in the Y-axis direction. That is, the light incident surfaces of the prisms 204 and 205 are arranged such that the light incident surfaces thereof are parallel to each other with a certain distance T _i .

The light beam group 202 emitted from the optical fiber array 201 and converted into parallel light by the collimating lens array 203 is bent (deflected) by passing through the wedge prism 204, and further passes through the right-angle prism 205. As a result, it is bent (deflected) and is incident on the reference surface R.

The distance between the light beams in the X-axis direction on the reference plane R is S _mirror-X , which is different from the distance S _fiber-X before incidence on the prism. However, the distance S between the light beams in the Y-axis direction on the reference plane R is
_{The mirror-Y} is the same as the spacing S _fiber-Y before entering the prism. After all, the conversion action of the light beam interval on the reference plane R occurs only in the X-axis direction and does not occur in the Y-axis direction as shown in FIG. That is, it is possible to convert the arrangement intervals of the light beams by focusing on a certain direction.

Next, an operation example of the optical beam array spacing conversion optical system according to the second embodiment will be described. Here, the wedge prism 204 and the rectangular prism 205
BK7 (manufactured by Schott), which is a quartz-based material, is used as the material of, the thickness T _prism of the wedge prism 204 is 12 [mm], the thickness T _c-prism of the right-angle prism 205 is 12 [mm], The distance T _i between the prisms is 5
[Mm], the wavelength of each light beam of the light beam group 202 is 15
50 [nm], and the fiber spacings S _fiber-X and S _fiber-Y on the X-axis and the Y-axis in the optical fiber array 201 are each 1.8 [mm].

Reference plane R with respect to the optical axis of the light beam group 202
The relative angle θ of the normal axis of is set to 15 [deg.], And the result obtained by using the ray tracing method for the relationship between the apex angle φ of the wedge prism 204 and the light beam interval S _{mi rror-X} on the reference plane R is As shown in FIG. From this result, when the apex angle φ of the wedge prism 204 is zero, that is, when there is no refraction by the wedge prism 204, the light beam interval S _{mirror-X on the} reference plane R is about 1.87 [mm]. However, it can be seen that S _mirror-X continuously decreases as the apex angle φ increases.

Further, the calculation result shows that in order to make the light beam interval S _mirror-X on the reference plane R equal to the optical fiber interval S _fiber-X , that is, S _mirror-X = 1.8 [mm], a wedge shape is obtained. The apex angle φ of the prism 204 is about 12.7 [de
g.] is set.

Incidentally, in the second embodiment shown in FIG.
One wedge prism 204 and one right angle prism 2
No. 05 is used, it is also possible to arrange two or more wedge prisms or two or more right-angle prisms. In this case, the arrangement of the plurality of prisms should satisfy the following conditions. The two-dimensionally arranged light beam group is incident on the frontmost prism, and the remaining prisms are arranged at positions where the light beam group deflected by the prism immediately before the prism is incident. Each prism deflects the light beam group in one one-dimensional direction (for example, X-axis direction) of the two-dimensional array, but in another one-dimensional direction (for example, Y-axis direction) of the two-dimensional array. Are arranged so as not to deflect the light beam group.

<Third Embodiment> Next, the third embodiment of the present invention will be described.
The array spacing conversion optical system for the two-dimensionally arrayed light beams according to the embodiment will be described with reference to FIG.

In the optical beam array spacing conversion optical system according to the above-described first and second embodiments,
It is possible to convert the arrangement intervals of the light beams by focusing on a certain direction, but the shape of the light beams (beam cross-sectional shape) also changes only in a certain direction due to the conversion action. For example, the cross-sectional shape of the light beam was circular before the array spacing was converted, but if the array spacing was converted by focusing on a certain direction, the cross-sectional shape of the light beam would be elliptical.

In general, when the shape of the light beam is asymmetrical between the XY axes which are orthogonal to each other, excessive connection loss occurs when the light beam is focused on the single mode optical fiber by using a lens or the like. Therefore, in the third embodiment, by arranging two sets of light beam arrangement interval conversion optical systems so as to face each other, the influence of the asymmetry of the light beam shape is removed while converting the arrangement intervals of the light beams. It makes it possible.

FIG. 6 shows a specific example of the free space type optical switch in which an array spacing conversion optical system for the light beams is introduced. 6, 301 is an input optical fiber array, 302 is a light beam, 303 is a collimating lens array, 306 and 307 are micro movable mirror arrays, 308 is a converging microlens array, 309 is an output optical fiber array, and A is A. The first set is an array spacing conversion optical system, and B is a second set of array spacing conversion optical systems.

The first set of array spacing conversion optical system A is
It is composed of a wedge prism 304a and a right angle prism 305a, and the wedge prism 20 of the second embodiment.
4 and the rectangular prism 205 are arranged in the same manner, and the conversion operation of the light beam interval is performed only in the X-axis direction. The second set of array spacing conversion optical system B is composed of a wedge prism 304b and a rectangular prism 305b, and is arrayed in the same manner as the wedge prism 204 and the rectangular prism 205 of the second embodiment. Therefore, the conversion operation of the light beam interval is performed only in the X-axis direction.

The light beam 302 emitted from the input optical fiber array 301 passes through the array spacing conversion optical system A and is deflected in the X-axis direction (not in the Y-axis direction), and the micro movable mirror arrays 306 and 307. In the X-axis direction (not in the Y-axis direction) and then enters the output optical fiber array 309 via the condensing microlens array 308.

The third embodiment, that is, the optical system constituting the free space type optical switch is arranged symmetrically with respect to the central portion between the micro movable mirror arrays 306 and 307 as shown in FIG. As a result, the shape change of the light beam shape caused by the array spacing conversion optical system A is
The array spacing conversion optical system B changes the shape in the opposite direction, and finally the asymmetry of the light beam shape can be eliminated.

More specifically, the first set of array spacing conversion optical system A is connected to the start end of the optical path (input optical fiber array 3
01 side) to the center (micro movable mirror array 306,
When viewed toward the central portion between 307, the right-angled prisms 305a are arranged next to the wedge prisms 304a, and the second set of array spacing conversion optical system B is connected to the end of the optical path (output optical fiber array 309). When viewed from the side) toward the center, right-angle prisms 305b are arranged next to the wedge prisms 304b, and when compared along the arrangement order, the prism shapes in the first set and the second set are the same. There is. That is, when comparing along the arrangement order,
In both the first set and the second set, the first prism shape is a wedge prism, the second prism shape is a right-angle prism, and the prism shapes are the same. Moreover,
When viewed along the above-mentioned arrangement order, the wedge-shaped prisms 304a on the first set side and the wedge-shaped prisms 304b on the second set side are arranged in the same direction, and the right-angled prisms on the first set side are arranged. The arrangement directions of the right-angle prism 305b on the second set side are the same as those of the second set 305a.

Therefore, for example, the array spacing conversion optical system A
The light beam 302 which has an elliptical light beam shape after passing through is returned to a circular light beam shape by passing through the array spacing conversion optical system B.

The array spacing conversion optical systems A and B are shown in FIG.
It may be configured by two wedge prisms as shown in FIG. Of course, even in this case, the shape and the direction of arrangement of the wedge-shaped prisms forming the arrangement interval conversion optical system A of the first set of light beams when viewed from the start end of the optical path toward the center. As seen from the end of the optical path toward the center, it is necessary that the shape and arrangement direction of each wedge-shaped prism forming the array spacing conversion optical system B of the second set of light beams are matched. is there.

[0049]

As described above in detail with the embodiments, according to the present invention, a plurality of wedge-shaped prisms are arranged at regular intervals and are inserted into the optical path of a two-dimensionally arranged light beam. Moreover, the arrangement state of each wedge-shaped prism is set in a state where the arrangement intervals of the light beams are focused and converted in a certain direction. Therefore, in the present invention, it is possible to convert the light beam array interval in the two-dimensionally arrayed light beam group by focusing only on a specific one-dimensional direction. Moreover, its configuration is simple.

In the present invention, a plurality of prisms, which are a right-angled prism and a wedge-shaped prism, are arranged at a constant interval and are inserted in the optical path of a two-dimensionally arranged light beam,
Moreover, the arrangement state of each prism is set in a state in which the arrangement interval of the light beams is focused and converted in a certain direction. Therefore, in the present invention, it is possible to convert the light beam array interval in the two-dimensionally arrayed light beam group by focusing only on a specific one-dimensional direction. Moreover, the structure is simple, and can be easily formed by using the wedge-shaped prism and the right-angled prism which are general-purpose products.

Further, the above-mentioned two sets of array conversion optical systems for the light beams are arranged so as to face each other and introduced into the input section and the output section of the free space optical switch, respectively. For this reason, the arrangement of the light beams can be converted, and of course, the non-axial symmetry of the shape of the light beams caused by the passage of the arrangement interval conversion optical system can be eliminated.

[Brief description of drawings]

FIG. 1 is a side view showing a light beam array spacing conversion optical system according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a light beam array spacing conversion optical system according to the first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a prism arrangement angle and an input / output light beam interval ratio in the first embodiment.

FIG. 4 is a side view showing a light beam array spacing conversion optical system according to a second embodiment of the present invention.

FIG. 5 is a characteristic diagram showing an apex angle of a wedge-shaped prism and a light beam interval on a reference surface in the second embodiment.

FIG. 6 is a side view showing a light beam array spacing conversion optical system according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing an example of a free space type optical switch.

FIG. 8 is a side view showing an example of a free space type optical switch.

FIG. 9 is a side view showing another example of the free space type optical switch.

[Explanation of symbols]

101 optical fiber array 102 Light beam group 103 Collimating lens array 104,105 wedge prism 201 Optical fiber array 202 light beam group 203 Collimating lens array 204 wedge prism 205 Right angle prism 206 reflective mirror 301 input optical fiber array 302 light beam 303 Collimating lens array 304a, 304b Wedge prism 305a, 305b Right angle prism 306,307 Micro movable mirror array 308 Condensing microlens array 309 Output Fiber Optic Array A, B array spacing conversion optical system R reference plane

Claims (4)

[Claims] 1. A plurality of wedge-shaped prisms are arranged at intervals to form a wedge-shaped prism, and a wedge-shaped prism at the frontmost stage receives a two-dimensionally arranged light beam group and the remaining wedge-shaped prisms. The prism is arranged at a position where the light beam group deflected by the wedge prism immediately before the wedge prism is incident, and each wedge prism is one dimension of one of the two-dimensional array. The two-dimensional array of light beams is arranged so as to deflect the light beam group with respect to a direction but not with respect to the other one-dimensional direction of the two-dimensional array. Interval conversion optical system. 2. A plurality of prisms, which are a right-angled prism and a wedge-shaped prism, are arranged at intervals, and a two-dimensionally arranged light beam group is incident on the frontmost prism. The remaining prisms are arranged at positions where the light beam group deflected by the prism immediately in front of the prism is incident, and each prism is arranged in the one-dimensional direction of one of the two-dimensional arrays. A two-dimensionally arranged optical beam array spacing conversion optical system, which is arranged so as to deflect the group but does not deflect the other one-dimensional direction of the two-dimensional array. . 3. The two sets of array spacing conversion optical systems for the light beams according to claim 1 are arranged, and when viewed from the starting end of the optical path toward the center,
The arrangement and orientation of the wedge prisms that form the array spacing conversion optical system of the first set of light beams, and the direction of the second set of light beams when viewed from the end to the center of the optical path. An array spacing conversion optical system for two-dimensionally arrayed light beams, characterized in that the shape and arrangement direction of each wedge prism constituting the array spacing conversion optical system are matched. 4. Two sets of the array spacing conversion optical system of the light beam according to claim 2 are arranged, and when viewed from the starting end of the optical path toward the center,
Arrangement Interval of the First Set of Light Beams The shape and arrangement direction of each prism constituting the conversion optical system, and the arrangement interval of the second set of light beams when viewed from the end to the center of the optical path. An array spacing conversion optical system for two-dimensionally arrayed light beams, characterized in that the shape and arrangement direction of each prism constituting the conversion optical system are matched.