Optical communication equipment

Abstract

To provide an optical communication device that suppresses the occurrence of resonance in the optical communication device due to the rotational movement of a wedge prism.SOLUTION: An optical communication device (10) has four wedge prisms (P111, P211, P121, and P221) rotatably arranged in an optical path of communication light. The four wedge prisms are arranged in a particular order or have a particular apex angle for each pair.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical communication device. [Background technology]

[0002] Radio wave communication technologies such as 5G (fifth generation mobile communication system) have dramatically increased speeds, but their communication speeds have already reached their theoretical upper limit. Realizing even faster communication speeds is difficult from the standpoints of cost and feasibility. Optical wireless communication technology is attracting attention as a technology that can achieve even faster communication speeds.

[0003] Although light is an electromagnetic wave, it has a higher degree of freedom in use than radio waves, and because it travels in a more directional direction, it does not propagate over a wide area like radio waves, giving it an advantage in terms of security. For this reason, it is considered suitable for communication between fixed objects, and is also considered advantageous as a technology to complement radio waves in space communications between artificial satellites.

[0004] In the field of optical communication technology, a technique is known in which a laser beam is scanned by rotating two wedge prisms in the same direction at different speeds (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-139692 Summary of the Invention [Problem to be solved by the invention]

[0006] Optical communication devices are often installed under vibration conditions because they are positioned according to their intended use. In such cases, the wedge prism rotates in a specific direction from time to time, which can cause vibrations in the optical communication device and lead to resonance. Conventional technologies leave room for further improvement in terms of suppressing the occurrence of resonance in optical communication devices due to the rotational movement of the wedge prism.

[0007] An object of one aspect of the present invention is to provide an optical communication device in which the occurrence of resonance in the optical communication device due to the rotational movement of a wedge prism is suppressed. [Means for solving the problem]

[0008] In order to solve the above problem, an optical communication device according to one embodiment of the present invention has four wedge prisms rotatably arranged in the optical path of communication light, two of the wedge prisms belong to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction, and the remaining two of the wedge prisms belong to a second wedge prism pair for adjusting the refraction angle of the communication light in a second direction, and at least one of the wedge prisms belonging to one of the wedge prism pairs is arranged between the two wedge prisms belonging to the other wedge prism pair.

[0009] In addition, in order to solve the above-mentioned problems, an optical communication device according to one embodiment of the present invention has four wedge prisms rotatably arranged in the optical path of the communication light, two of the wedge prisms each having a first apex angle and belonging to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction, and the remaining two of the wedge prisms each having a second apex angle and belonging to a second wedge prism pair for adjusting the refraction angle of the communication light in a second direction. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to realize an optical communication device in which the occurrence of resonance in the optical communication device due to the rotational movement of a wedge prism is suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram schematically illustrating an outline of the configuration of an optical communication device according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a diagram schematically illustrating a functional configuration of an optical communication device according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the arrangement of wedge prisms in the first embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing the arrangement of wedge prisms in the second embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing the arrangement of wedge prisms in a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0013] [Configuration of optical communication equipment] Fig. 1 is a diagram schematically illustrating an outline of the configuration of an optical communication device according to a first embodiment of the present invention. As shown in Fig. 1, the optical communication device 10 has four wedge prisms rotatably arranged in the optical path of communication light. More specifically, the optical communication device 10 has a casing 11, a mount 12 that supports the casing 11 so that it can rotate, a light-emitting element 13 arranged in the casing 11, and an optical axis adjustment device 14 that adjusts the propagation direction of light emitted from the light-emitting element 13.

[0014] The casing 11 is a housing that houses an optical system for optical communication. The mount 12 is configured to support the casing 11, and has, for example, a motor as a drive source, and supports the casing 11 so that it can turn.

[0015] The light emitting element 13 is an element that generates light that can be used for optical communication, and may be, for example, an element that converts electricity into light. Examples of the light emitting element 13 include a light emitting diode and a semiconductor laser.

[0016] The optical axis adjustment device 14 includes a first wedge prism unit 15 and a second wedge prism unit 16. The first wedge prism unit 15 is made up of two of the four wedge prisms that are on the light emitting element 13 side (upstream side in the propagation direction of the communication light). The second wedge prism unit 16 is made up of two of the four wedge prisms that are downstream in the propagation direction of the communication light. The four wedge prisms are arranged to be rotatable about the same rotation axis CA.

[0017] Two of the four wedge prisms cooperate to refract the communication light in two directions: a first direction and a second direction. In this embodiment, a plane perpendicular to the rotation axis CA is defined as the yaw direction, and a vertical direction in this plane is defined as the pitch direction. In this embodiment, the yaw direction corresponds to the first direction, and the pitch direction corresponds to the second direction. Two of the four wedge prisms in the optical axis adjustment device control the refraction of the communication light in the yaw direction. The remaining two of the four wedge prisms in the optical axis adjustment device control the refraction of the communication light in the pitch direction. The arrangement and operation of the wedge prisms will be described in detail below.

[0018] 2 is a diagram showing a schematic functional configuration of an optical communication device according to an embodiment of the present invention. As shown in FIG. 2, the optical axis adjustment device 14 includes a wedge prism rotation mechanism corresponding to each wedge prism unit, an acceleration sensor 17, and a controller 18.

[0019] The first wedge prism unit 15 includes a first wedge prism P111 arranged upstream in the propagation direction of the communication light, and a second wedge prism P211 arranged downstream in the propagation direction of the communication light. The first wedge prism unit 15 has a holder 110, a coil 111, and a position sensor 112 as a rotation mechanism for the first wedge prism P111, and a holder 210, a coil 211, and a position sensor 212 as a rotation mechanism for the second wedge prism P211.

[0020] The second wedge prism unit 16 includes a third wedge prism P121 arranged upstream in the propagation direction of the communication light and a fourth wedge prism P221 arranged downstream in the propagation direction of the communication light. The second wedge prism unit 16 has a holder 120, a coil 121, and a position sensor 122 as a rotation mechanism for the third wedge prism P121, and a holder 220, a coil 221, and a position sensor 222 as a rotation mechanism for the fourth wedge prism P221.

[0021] The holders 110, 210, 120, and 220 are annular plate-shaped members, which hold a wedge prism in the central opening and are arranged within the casing 11 so as to be rotatable about a rotation axis CA.

[0022] Coils 111, 211, 121, and 221 are members that, when energized, generate magnetic poles that rotate holders 110, 210, 120, and 220. Depending on the magnetic poles generated in coils 111, 211, 121, and 221, an attractive force or a repulsive force is generated between coils 111, 211, 121, and 221 and the magnets (not shown) that face them, and holders 110, 210, 120, and 220 rotate at a rotation angle that corresponds to the attractive force or the repulsive force.

[0023] The position sensors 112, 212, 122, and 222 are sensors for detecting the rotational position of the corresponding wedge prisms P111, P211, P121, and P221 (for example, the position of the apex angle of the wedge prism). The position sensors 112, 212, 122, and 222 are configured, for example, by Hall elements fixed to the holders 110, 210, 120, and 220, and corresponding magnets fixed to the casing 11.

[0024] The acceleration sensor 17 is a sensor that detects the inclination of the optical communication device 10 (or the casing 11).

[0025] The controller 18 determines the tilt of the optical communication device 10 by referring to the signal from the acceleration sensor 17, calculates the rotation angle of the wedge prism based on the determined tilt, and outputs a signal corresponding to the rotation angle. The controller 18 is configured, for example, as an integrated circuit equipped with an input unit, a calculation unit, a control unit, a memory unit, and an output unit. The controller 18 is configured to receive signals from the position sensors 112, 212, 122, 222 and the acceleration sensor 17 and output signals to the coils of each wedge prism pair. Here, a "wedge prism pair" refers to a combination of two wedge prisms that move together to refract communication light in the yaw or pitch direction.

[0026] The wedge prisms P111, P211, P121, and P221 all have the same dimensions and the same apex angle.

[0027] [Wedge prism placement] The first wedge prism P111 arranged in the first wedge prism unit 15 and the third wedge prism P121 arranged in the second wedge prism unit 16 rotate so as to adjust the refraction angle in the yaw direction within the propagation direction of the communication light emitted from the light emitting element 13. For example, the optical axis adjustment device 14 is configured so that the first wedge prism P111 and the third wedge prism P121 rotate in opposite directions to each other.

[0028] The second wedge prism P211 arranged in the first wedge prism unit 15 and the fourth wedge prism P221 arranged in the second wedge prism unit 16 rotate so as to adjust the refraction angle in the pitch direction of the propagation direction of the communication light emitted from the light emitting element 13. For example, the optical axis adjustment device 14 is configured so that the second wedge prism P211 and the fourth wedge prism P221 rotate in opposite directions to each other.

[0029] Fig. 3 is a diagram showing the arrangement of wedge prisms in Embodiment 1 of the present invention. As shown in Fig. 3, the first wedge prism unit 15 has a first wedge prism P111 for adjusting the refraction angle of the communication light in the yaw direction and a second wedge prism P211 for adjusting the refraction angle of the communication light in the pitch direction. In addition, the second wedge prism unit 16 has a third wedge prism P121 for adjusting the refraction angle of the communication light in the yaw direction and a fourth wedge prism P221 for adjusting the refraction angle of the communication light in the pitch direction.

[0030] Thus, in the optical communication device 10, the first wedge prism P111 and the third wedge prism P121 belong to a first wedge prism pair for adjusting the refraction angle of the communication light in the yaw direction. Also, in the optical communication device 10, the second wedge prism P211 and the fourth wedge prism P221 belong to a second wedge prism pair for adjusting the refraction angle of the communication light in the pitch direction.

[0031] As described above, in the optical communication device 10, the second wedge prism P211 belonging to the second wedge prism pair is disposed between the two wedge prisms, the first wedge prism P111 and the third wedge prism P121, belonging to the first wedge prism pair. More specifically, in the optical communication device 10, the wedge prisms P111 and P121 belonging to the first wedge prism pair and the wedge prisms P211 and P221 belonging to the second wedge prism pair are disposed alternately.

[0032] [Propagation direction adjustment behavior] In this embodiment, the rotation of the wedge prism can be achieved by, for example, having the controller 18 calculate the rotation angle of the wedge prism from the output value of the acceleration sensor 17 and performing PWM (pulse width modulation) control on the coils 111, 211, 121, and 221. The controller 18 also receives signals from the position sensors 112, 212, 122, and 222 to determine the rotation position of the wedge prism and perform feedback processing to control the rotational movement of the wedge prism. The rotation angle of the wedge prism is confirmed by the position of the apex angle of the wedge prism.

[0033] Of the four wedge prisms in the optical axis adjustment device 14, two, the first wedge prism P111 and the third wedge prism P121, rotate in opposite directions and at rotation angles that are the same in absolute value. This rotation adjusts the yaw direction component of the refraction angle of the communication light. Furthermore, of the four wedge prisms in the optical axis adjustment device 14, two, the second wedge prism P211 and the fourth wedge prism P221, rotate in opposite directions and at rotation angles that are the same in absolute value. This rotation adjusts the pitch direction component of the refraction angle of the communication light. Thus, in this embodiment, the rotation directions of the two wedge prisms belonging to the same wedge prism pair are opposite to each other, and the absolute values ​​of the rotation angles of the two wedge prisms belonging to the same wedge prism pair are the same.

[0034] For the two wedge prisms in each wedge prism pair, the refraction angle in the propagation direction of the communication light exhibits a substantially linear correlation with the rotation angle of the wedge prism. Therefore, the rotation angle of the wedge prism and the refraction angle in the propagation direction of the communication light are linearly approximated. The rotation angle of the wedge prism is calculated based on this linear approximation. Furthermore, the refraction angle can be increased by rotating the two wedge prisms in each wedge prism pair in opposite directions.

[0035] [Major effects] Optical communication devices are subject to shift vibrations that move up and down relative to a reference height. In order to isolate optical communication devices, it is necessary to control the propagation direction of communication light within a frequency range of 1 to 100 Hz and a refraction angle of approximately 5°, taking into account the frequency range and type of vibration.

[0036] The refraction angle of the propagation direction of the communication light can be easily expressed as the distance in each of two directions (yaw direction and pitch direction) perpendicular to the optical axis of the light-emitting element. This refraction angle can be easily converted into the rotation angle of the wedge prism, and the rotation angle of the wedge prism that achieves the desired refraction angle can be quickly determined. Furthermore, the rotational movement of the wedge prism can be quickly performed. Therefore, in this embodiment, it is possible to substantially eliminate the influence of changes in the propagation direction of the communication light due to vibrations in the optical communication device.

[0037] Furthermore, in the optical communication device of this embodiment, as described above, the rotation directions of the paired wedge prisms are opposite to each other, and the absolute value of the rotation angle is the same. Therefore, compared to rotating the wedge prism in one direction, it is possible to control the propagation direction of the communication light over a wide range with a small rotation angle, and it is also possible to control the propagation direction quickly. Therefore, it is suitable for optical communication, and the small rotation angle is also suitable from the viewpoint of preventing resonance.

[0038] The optical communication device of this embodiment is suitable for preventing resonance of the optical communication device due to the rotational movement of the wedge prism as described above when the optical communication device is in a vibrating state, and for suppressing vibration of the optical communication device. The reasons for such vibration isolation in this embodiment are thought to include the following mechanical reasons.

[0039] For example, in the optical communication device of this embodiment, the distance between the pair of wedge prisms that rotate in opposite directions by the same angle is longer than when they are arranged in the same wedge prism unit. This increases the moment of motion caused by the pair of rotating wedge prisms. Therefore, the vibrations caused by the rotational motion of the wedge prisms cancel out the vibrations of the optical communication device.

[0040] In the optical communication device of this embodiment, for the reasons described above, the rotational motion of the wedge prism pair is likely to be biased, which may lead to the component of the communication light vibration in one direction being more easily converged, and therefore the component in the other direction also being more easily converged.

[0041] Furthermore, in the optical communication device of this embodiment, as described above, the distance between the wedge prisms of the same pair, which rotate at the same angle, is longer than when they are arranged in the same wedge prism unit. Therefore, the effect of refraction by the wedge prisms is greater. In this embodiment, by sandwiching at least one wedge prism of a pair between two wedge prisms of another pair, it is possible to increase the distance between the two wedge prisms of a pair while minimizing the distance between all adjacent wedge prisms. If each pair of wedge prisms were arranged with the distance between the two wedge prisms of a pair increased without sandwiching at least one wedge prism of the other pair between them, a gap of approximately one wedge prism would be created between the pair, resulting in an increase in size. Therefore, arranging the wedge prisms in a reversed order, as in this embodiment, is advantageous from the perspective of miniaturizing the arrangement of the wedge prisms.

[0042] [Application] The optical communication device 10 is suitable for use as a beacon. A beacon emits a light beam over a wide area to notify the other party of its location. In a beacon, the light beam is directed in an approximate direction to scan within a specific area. The direction of light emission is determined by combining the pitch angle and the yaw angle. While it is usually difficult to accurately capture the location of a communication partner in a large space, the optical communication device of this embodiment is capable of rapid scanning, making it suitable for use as a beacon.

[0043] In optical communication devices using a pair of wedge prisms, the rotational motion of the pair of wedge prisms can become noise, causing and amplifying vibrations in the optical communication device. In the optical communication device of this embodiment, such vibrations in the optical communication device are suppressed by the rotational motion of the pair of wedge prisms. Examples of optical communication devices suitable for this embodiment include optical communication devices that are supported so as to be able to rotate freely and optical communication devices that are located in a zero-gravity environment such as outer space.

[0044] In particular, in this embodiment, the distance between the wedge prisms in each pair is approximately the same, being larger by about the width of one wedge prism. Therefore, this embodiment is suitable for suppressing vibrations in an optical communication device that scans communication light in a direction where the difference in magnitude between the yaw direction component and the pitch direction component is large, such as when the communication light is moved back and forth over a certain range mainly in the yaw direction or pitch direction.

[0045] [Embodiment 2] Another embodiment of the present invention will be described below. For ease of explanation, components having the same functions as those described in the previous embodiment will be denoted by the same reference numerals, and their description will not be repeated. The optical communication device of this embodiment is configured in the same way as the optical communication device of the first embodiment, except for the arrangement of the wedge prisms in the wedge prism unit.

[0046] [Wedge prism placement] FIG. 4 is a diagram showing the arrangement of wedge prisms in Embodiment 2 of the present invention. As shown in FIG. 4, the first wedge prism unit 15 includes a first wedge prism P112 belonging to a first wedge prism pair for adjusting the refraction angle of the communication light in the yaw direction and a second wedge prism P212 belonging to a second wedge prism pair for adjusting the refraction angle of the communication light in the pitch direction. The second wedge prism unit 16 includes a third wedge prism P222 belonging to the second wedge prism pair for adjusting the refraction angle of the communication light in the pitch direction and a fourth wedge prism P122 belonging to the first wedge prism pair for adjusting the refraction angle of the communication light in the yaw direction. That is, in this embodiment, two wedge prisms belonging to one wedge prism pair are disposed between two wedge prisms belonging to the other wedge prism pair.

[0047] [Propagation direction adjustment behavior] In this embodiment, the first wedge prism P112 and the fourth wedge prism P122 rotate in opposite directions by the same rotation angle to adjust the yaw component of the refraction angle of the communication light, and the second wedge prism P212 and the third wedge prism P222 rotate in opposite directions by the same rotation angle to adjust the pitch component of the refraction angle of the communication light.

[0048] [Major effects] The optical communication device of this embodiment, like the optical communication device of embodiment 1, can prevent resonance caused by the rotational motion of the wedge prism and suppress vibration of the optical communication device. The reasons for this include the following mechanical reasons.

[0049] For example, in this embodiment, the distance between the wedge prisms of the first wedge prism pair, which adjusts the refraction angle in the yaw direction, is longer than the distance between the wedge prisms of the second wedge prism pair, which adjusts the refraction angle in the pitch direction. Therefore, when compared at the same rotation angle, the magnitude of the moment during operation due to the wedge prisms rotating in pairs is larger in the first wedge prism pair and smaller in the second wedge prism pair.

[0050] In this embodiment, a difference occurs in the magnitude of the moment due to the rotational movement between the two wedge prism pairs, which makes it easier for a difference to occur in the rotational movement of the two wedge prism pairs, making it difficult for resonance to occur.

[0051] Therefore, this embodiment is suitable for suppressing vibrations in an optical communication device that scans communication light in a direction where the yaw component and pitch component are approximately the same magnitude, such as at a 45° angle.

[0052] Furthermore, in the optical communication device of this embodiment, by sandwiching a pair of wedge prisms between another pair of wedge prisms, it is possible to minimize the distance between all adjacent wedge prisms while increasing the distance between the wedge prisms in a given pair. Therefore, like the first embodiment, this embodiment is advantageous in terms of miniaturizing the arrangement of wedge prisms.

[0053] [Embodiment 3] Another embodiment of the present invention will be described below. For ease of explanation, components having the same functions as those described in the previous embodiment will be denoted by the same reference numerals, and their description will not be repeated. The optical communication device of this embodiment is configured in the same manner as the optical communication device of the first embodiment, except for the shape and arrangement of the wedge prism in the wedge prism unit.

[0054] [Wedge prism placement] Fig. 5 is a diagram showing the arrangement of wedge prisms in embodiment 3 of the present invention. As shown in Fig. 5, the first wedge prism unit 15 has a first wedge prism P113 and a second wedge prism P123 that belong to a first wedge prism pair for adjusting the refraction angle of the communication light in the yaw direction. Furthermore, the second wedge prism unit 16 has a third wedge prism P213 and a fourth wedge prism P223 that belong to a second wedge prism pair for adjusting the refraction angle of the communication light in the pitch direction.

[0055] The first wedge prism P113 and the second wedge prism P123 have the same dimensions and a first apex angle θ. The third wedge prism P213 and the fourth wedge prism P223 have the same dimensions as the first wedge prism P113 and the second wedge prism P123, except that they each have a second apex angle γ. θ is larger than γ. Small The difference is, for example, 0.1 to 10°, and more preferably 0.1 to 7°.

[0056] [Propagation direction adjustment behavior] In this embodiment, the first wedge prism P113 and the second wedge prism P123 rotate in opposite directions by the same rotation angle to adjust the yaw component of the refraction angle of the communication light. The third wedge prism P213 and the fourth wedge prism P223 rotate in opposite directions by the same rotation angle to adjust the pitch component of the refraction angle of the communication light. When the propagation direction of the communication light is refracted by the same refraction angle, the rotation angle of the wedge prisms P113 and P123 of the first wedge prism pair is greater than the rotation angle of the wedge prisms P213 and P223 of the second wedge prism pair.

[0057] [Major effects] The optical communication device of this embodiment, like the optical communication device of embodiment 1, can prevent resonance caused by the rotational motion of the wedge prism and suppress vibration of the optical communication device. The reasons for this include the following mechanical reasons.

[0058] For example, in the optical communication device of this embodiment, when the propagation direction of communication light is refracted at the same refraction angle, the rotation angle of the wedge prisms in the first wedge prism pair is larger than that of the second wedge prism pair, and therefore the moment due to the rotational motion of the first wedge prism pair is also larger than that of the second wedge prism pair.

[0059] Therefore, in the optical communication device of this embodiment, the magnitude of the rotational movement of the wedge prisms between the wedge prism pairs tends to be uneven, which makes it easier to converge and prevent vibrations in the optical communication device caused by each wedge prism pair.

[0060] Furthermore, in the optical communication device of this embodiment, in order to use only a wedge prism pair having one refraction angle and achieve refraction of communication light by the other wedge prism pair having a different refraction angle, it may be necessary to increase the spacing between the wedge prisms in the wedge prism pair having one refraction angle. In this embodiment, by using wedge prism pairs having different refraction angles, the distance between all adjacent wedge prisms is minimized while achieving the above-mentioned optical characteristics achieved by wedge prism pairs having different refraction angles. Therefore, like the above-described first and second embodiments, this embodiment is advantageous in terms of miniaturizing the arrangement of wedge prisms.

[0061] [Modification] In the above-described embodiment, the optical communication device has been described as a device on the emitting side of communication light, but the optical communication device of the present invention may also be a device on the receiving side. Such a receiving-side optical communication device is configured by having a light-receiving element instead of the above-described light-emitting element. An element that converts light into electricity can be suitably used as the light-receiving element. Examples of the light-receiving element include a photodiode and a CMOS image sensor.

[0062] The optical communication device of the present invention may further include a third or subsequent wedge prism pair, as long as the third or subsequent wedge prism pair includes a wedge prism that satisfies the requirements of the above embodiment.

[0063] In the present invention, the configuration of the above-described embodiment 1 or embodiment 2 may be adopted in the above-described embodiment 3. In this case, it is expected that both the effects of embodiment 1 or embodiment 2 and embodiment 3 will be achieved.

[0064] In the present invention, within the range in which the propagation direction of the communication light can be controlled to the desired direction, the rotation directions of the wedge prisms in the wedge prism pair may all be the same direction, or may be rotated by rotation angles with different absolute values.

[0065] In the present invention, a gyro sensor may be provided instead of or in addition to the acceleration sensor. The optical communication device may be subject to rotational vibration, which occurs when the device rotates around an arbitrary location. A gyro sensor is advantageous for detecting rotational vibration. This configuration is suitable for suppressing rotational vibration in the optical communication device.

[0066] The present invention may further include a control for adjusting the rotation speed of the wedge prisms so that the rotation speeds of the wedge prisms differ between the pair of wedge prisms in accordance with the rotation angle of the wedge prisms calculated by the controller. In the above-described embodiment, the rotation speed of the wedge prisms can be adjusted by the current value of the coil. Such additional control is expected to have the effect of suppressing vibration and resonance.

[0067] [Experimental Example 1] Using an optical communication device having the same configuration as the third embodiment described above except for using four wedge prisms each having the same apex angle, control of the propagation direction of communication light oscillating in a direction including both yaw and pitch components was performed under the following conditions. The vibration of the optical communication device at this time was then determined. As a result of this control, it was confirmed that vibration occurred in the optical communication device in the same direction as the vibration of the communication light. (conditions) Wedge prism diameter: 35mm Wedge prism apex angle: 0.1° Rotation direction: Opposite directions for the wedge prism pair Rotation angle (absolute value): 10° Vibration direction of communication light: Random Amplitude of communication light: 1 mrad Vibration frequency: 15Hz

[0068] [Experimental Example 2] A wedge prism was arranged in the same manner as in the above-described embodiment 1, and the rotational motion was controlled in the same manner as in embodiment 1. Except for this, the propagation direction of the communication light was controlled in the same manner as in experimental example 1. As a result, no vibration was observed in the optical communication device.

[0069] [Experimental Example 3] A wedge prism was placed in the same manner as in the second embodiment, and the rotational motion was controlled in the same manner as in the second embodiment, but the propagation direction of the communication light was controlled in the same manner as in the first experimental example. As a result, no vibration was observed in the optical communication device.

[0070] [Experimental Example 4] The same wedge prism as in the above-described embodiment 3 was used, and the control of the propagation direction of the communication light was carried out in the same manner as in Experimental Example 1, except that the rotational motion was controlled in the same manner as in embodiment 3. As a result, no vibration was observed in the optical communication device.

[0071] As is clear from the above experimental examples, the above-described embodiment of the present invention prevents vibration and resonance of the optical communication device due to rotation of the wedge prism. Therefore, the embodiment of the present invention easily cancels out vibration of the optical communication device and makes it possible to prevent resonance in at least two sets of two pairs of wedge prisms, which is expected to contribute to attitude control of the optical communication device in zero gravity.

[0072] 〔summary〕 As is clear from the above description, the optical communication device (10) according to the embodiment of the present invention has four wedge prisms (P111, P211, P121, P221) rotatably arranged in the optical path of the communication light. Two of the wedge prisms (P111, P121) belong to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction, and the remaining two wedge prisms (P211, P221) belong to a second wedge prism pair for adjusting the refraction angle of the communication light in a second direction, with at least one wedge prism belonging to one wedge prism pair being arranged between two wedge prisms belonging to the other wedge prism pair.

[0073] Alternatively, an optical communication device according to an embodiment of the present invention includes four wedge prisms rotatably arranged in the optical path of communication light, where two wedge prisms (P113, P123) each have a first apex angle and belong to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction, and the remaining two wedge prisms (P213, P223) each have a second apex angle and belong to a second wedge prism pair for adjusting the refraction angle of the communication light in a second direction.

[0074] Any of the above optical communication devices can realize an optical communication device in which the occurrence of resonance in the optical communication device due to the rotational movement of the wedge prism is suppressed.

[0075] In the latter optical communication device, the two wedge prisms belonging to one wedge prism pair may be arranged in this order, followed by the two wedge prisms belonging to the other wedge prism pair, which is even more effective in suppressing vibrations in the optical communication device due to the rotational movement of the wedge prisms.

[0076] In an embodiment of the present invention, the wedge prisms belonging to the first wedge prism pair and the wedge prisms belonging to the second wedge prism pair may be arranged alternately, which is even more effective in suppressing vibrations in the optical communication device caused by the rotational movement of the wedge prisms.

[0077] In an embodiment of the present invention, two wedge prisms belonging to one wedge prism pair may be disposed between two wedge prisms belonging to the other wedge prism pair, which is even more effective in suppressing vibrations in the optical communication device caused by the rotational movement of the wedge prisms.

[0078] In an embodiment of the present invention, the rotation directions of the two wedge prisms in the same wedge prism pair may be opposite to each other, and the absolute values ​​of the rotation angles of the two wedge prisms in the same wedge prism pair may be the same. This configuration is even more effective in terms of controlling the communication light in optical communications and suppressing vibrations in the optical communications device.

[0079] The present invention is expected to contribute to the construction and development of robust optical communication networks, and to the achievement of the Sustainable Development Goals (SDGs) regarding the foundations of industry and technological innovation.

[0080] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0081] 10 Optical communication equipment 11 Casing 12 Mounting stand 13 Light-emitting element 14 Optical axis adjustment device 15 First wedge prism unit 16 Second wedge prism unit 17 Acceleration Sensor 18 Controller 110, 120, 210, 220 holder 111, 121, 211, 221 coils 112, 122, 212, 222 Position Sensors P111, P112, P113 First wedge prism P123, P211, P212 Second wedge prism P121, P213, P222 Third Wedge Prism P122, P221, P223 Fourth Wedge Prism CA Rotation Axis

Claims

1. four wedge prisms rotatably disposed in the optical path of the communication light; the two wedge prisms belong to a first wedge prism pair for adjusting a refraction angle of the communication light in a first direction; the remaining two wedge prisms belong to a second wedge prism pair for adjusting the refraction angle of the communication light in a second direction; At least one wedge prism belonging to one of the wedge prism pairs is disposed between two of the wedge prisms belonging to the other wedge prism pair. Optical communication equipment.

2. 2. The optical communication device according to claim 1, wherein the wedge prisms belonging to the first wedge prism pair and the wedge prisms belonging to the second wedge prism pair are arranged alternately.

3. 2. The optical communication device according to claim 1, wherein two of the wedge prisms belonging to one of the wedge prism pairs are disposed between two of the wedge prisms belonging to the other wedge prism pair.

4. four wedge prisms rotatably disposed in the optical path of the communication light; the two wedge prisms each have a first apex angle and belong to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction; the remaining two wedge prisms each have a second apex angle different from the first apex angle and belong to a second wedge prism pair for adjusting the refraction angle of the communication light in the second direction; Optical communication equipment.

5. 5. The optical communication device according to claim 4, wherein the two wedge prisms belonging to one of the wedge prism pairs and the two wedge prisms belonging to the other wedge prism pair are arranged in this order.

6. An optical communication device according to any one of claims 1 to 5, wherein the rotation directions of the two wedge prisms belonging to the same wedge prism pair are opposite to each other, and the absolute values ​​of the rotation angles of the two wedge prisms belonging to the same wedge prism pair are the same.

7. A communication system having four wedge prisms rotatably arranged in the optical path of communication light, the two wedge prisms each have a first apex angle and belong to a first wedge prism pair for adjusting the refraction angle of the communication light in a first direction; the remaining two wedge prisms each have a second apex angle and belong to a second wedge prism pair for adjusting the refraction angle of the communication light in the second direction; the rotation directions of the two wedge prisms belonging to the same wedge prism pair are opposite to each other, and the absolute values ​​of the rotation angles of the two wedge prisms belonging to the same wedge prism pair are the same; Optical communication equipment.

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