Device for optical communication

Abstract

The invention relates to a device for optical communication. The apparatus comprises: a transmission unit comprising a first dual-core optical fiber, a first core of which transmits first signal light and a second core of which transmits first calibration light; the receiving unit comprises a second double-core optical fiber, a third core of the second double-core optical fiber receives second signal light, and a fourth core of the second double-core optical fiber transmits second calibration light; a transceiver unit configured to transmit the first signal light to another device, transmit the first and second calibration light to the fine tracking unit, receive the second signal light from another device, and transmit the second signal light to the fine tracking unit and the receiving unit; a fine tracking unit configured to detect a first position of the first calibration light, a second position of the second calibration light, and a third position of the second signal light; and a control unit configured to calibrate an optical axis of the device based on at least one of the first position, the second position, and the third position. According to the device for optical communication, the optical axis can be efficiently and accurately calibrated.

Description

Technical Field

[0001] The present invention relates to the field of optical communication, and more particularly to a device for optical communication. Background Art

[0002] During the optical communication process, the optical axis of the device used for optical communication needs to be in a preset direction so that the signal light is aligned with the corresponding optical element in the device, so that the device has a higher signal-to-noise ratio. However, for example, in the case of large bumps or stress during the transportation of the device used for optical communication, the optical axis of the device may deviate from the preset direction, resulting in the device having a poor signal-to-noise ratio during the optical communication process, resulting in poor optical communication quality. Therefore, it is necessary to calibrate the optical axis of the device. Usually, after the device scans another device with which it will communicate optically (for example, during the link establishment process), the device calibrates the optical axis of the device by detecting the intensity of the signal light received from the other device, adjusting the inclination angle of the corresponding optical device of the device according to the detected intensity, and repeating this process. However, this calibration process takes a long time and cannot accurately calibrate the optical axis of the device to the preset direction.

[0003] In summary, the disadvantages of conventional devices for optical communication are that it takes a long time to calibrate the optical axis of the device and the calibration accuracy is low. Summary of the invention

[0004] The present invention provides a device for optical communication, which can realize efficient and accurate calibration of an optical axis.

[0005] According to a first aspect of the present invention, an optical communication device is provided. The device comprises: a transmitting unit, comprising a first double-core optical fiber, the first double-core optical fiber comprises a first core and a second core, the first core is configured to transmit a first signal light, and the second core is configured to transmit a first calibration light; a receiving unit, comprising a second double-core optical fiber, the second double-core optical fiber comprises a third core and a fourth core, the third core is configured to receive a second signal light, and the fourth core is configured to transmit a second calibration light, wherein the second signal light comes from another device that performs optical communication with the device; a transceiver unit, configured to send the first signal light to the other device, transmit the first calibration light and the second calibration light to a precision tracking unit, receive the second signal light from the other device and transmit the second signal light to the precision tracking unit and the receiving unit; a precision tracking unit, configured to detect a first position of a first light spot formed by the first calibration light in the precision tracking unit, a second position of a second light spot formed by the second calibration light in the precision tracking unit, and a third position of a third light spot formed by the second signal light in the precision tracking unit; and a control unit, configured to calibrate the optical axis of the device based on at least one of the first position, the second position, and the third position.

[0006] In some embodiments, the optical axis includes: a first optical axis for transmission of the first signal light in the device, and a second optical axis for transmission of the second signal light in the device, and the calibration makes: in the transceiver unit, the first optical axis overlaps with the second optical axis.

[0007] In some embodiments, in a non-optical communication stage when the device is not performing optical communication, the control unit is configured to calibrate the optical axis of the device as follows: determine a first relative distance between the first position and the second position; obtain a first relative angle between the first calibration light and the second calibration light based on the first relative distance and the focal length of the fine tracking lens group in the fine tracking unit; compare the first relative angle with a first predetermined relative angle to obtain a first comparison result; and adjust the tilt angle of at least one fast reflex mirror in the device based on the first comparison result to calibrate the first optical axis and the second optical axis.

[0008] In some embodiments, the first predetermined relative angle is determined based on: a spacing between the first core and the second core, a spacing between the third core and the fourth core, a focal length of a transmitting mirror group in the transmitting unit, and a focal length of a receiving mirror group in the receiving unit.

[0009] In some embodiments, during the optical communication stage when the device performs optical communication, the control unit is configured to calibrate the optical axis of the device as follows: determine a second relative distance between the second position and the third position; calibrate the second optical axis based on the second relative distance; determine a third relative distance between the first position and the third position after calibrating the second optical axis; and calibrate the first optical axis based on the third relative distance.

[0010] In some embodiments, the control unit is configured to calibrate the second optical axis based on the second relative distance as follows: obtain a second relative angle between the second calibration light and the second signal light based on the second relative distance and the focal length of the fine tracking lens group in the fine tracking unit; compare the second relative angle with a second predetermined relative angle to obtain a second comparison result; and adjust the tilt angle of the fast reflection mirror in the transceiver unit based on the second comparison result to adjust the second relative angle to the second predetermined relative angle.

[0011] In some embodiments, the control unit is configured to calibrate the first optical axis based on the third relative distance as follows: based on the third relative distance and the focal length of the fine tracking lens group in the fine tracking unit, obtain a third relative angle between the first calibration light and the second signal light after calibrating the second optical axis; compare the third relative angle with a third predetermined relative angle to obtain a third comparison result; and based on the third comparison result, adjust the tilt angle of the fast reflection mirror in the transmitting unit to adjust the third relative angle to the third predetermined relative angle.

[0012] In some embodiments, the second predetermined relative angle is determined based on the following items: the spacing between the third core and the fourth core, and the focal length of the receiving mirror group in the receiving unit, and the third predetermined relative angle is determined based on the following items: the spacing between the first core and the second core, and the focal length of the transmitting mirror group in the transmitting unit.

[0013] In some embodiments, the transmitting unit further includes: a transmitting mirror group optically coupled to the first double-core optical fiber; and a first fast reflection mirror optically coupled to the transmitting mirror group.

[0014] In some embodiments, the transceiver unit includes: a first beam splitter, a second fast reflex mirror, a first reflector, an optical antenna, a cone, a second beam splitter, and a second reflector, wherein the first signal light is sent to the other device via the first core, the transmitting mirror group, the first fast reflex mirror, the first beam splitter, the second fast reflex mirror, the first reflector, and the optical antenna in sequence, the first calibration light is transmitted to the fine tracking unit via the second core, the transmitting mirror group, the first fast reflex mirror, the first beam splitter, the cone, the first beam splitter, the second beam splitter, and the second reflector in sequence, the second signal light is transmitted to the receiving unit via the optical antenna, the first reflector, the second fast reflex mirror, the first beam splitter, and the second beam splitter in sequence, and is also transmitted to the fine tracking unit via the second reflector optically coupled to the second beam splitter, and the second calibration light is transmitted from the receiving unit via the second beam splitter, the first beam splitter, the cone, the first beam splitter, the second beam splitter, and the second reflector in sequence.

[0015] In some embodiments, the transceiver unit further includes: an optical filter optically coupled in the light path between the first beam splitter and the second beam splitter, or optically coupled in the light path between the first beam splitter and the corner cone.

[0016] In some embodiments, the receiving unit further comprises: a receiving mirror set optically coupled to the second beam splitter, wherein the second double-core optical fiber is optically coupled to the receiving mirror set.

[0017] In some embodiments, the fine tracking unit includes: a fine tracking lens group optically coupled to the second reflector; and a camera optically coupled to the fine tracking lens group.

[0018] In some embodiments, a spacing between the first core and the second core is greater than a diameter of the first core and a diameter of the second core, and a spacing between the third core and the fourth core is greater than a diameter of the third core and a diameter of the fourth core.

[0019] In some embodiments, the wavelength of the first signal light is different from the wavelength of the second signal light and is different from the wavelength of the first calibration light, and the wavelength of the second signal light is different from the wavelength of the second calibration light.

[0020] In some embodiments, the device is an onboard device disposed on a satellite.

[0021] It should be understood that the beneficial effect of the present invention is that by calibrating the optical axis of the device used for optical communication based on the positions of the light spots formed by the first calibration light, the second calibration light and the second signal light detected by the precision tracking unit, the efficiency and accuracy of calibrating the optical axis of the device can be improved, thereby improving the communication quality of the device for optical communication.

[0022] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements.

[0024] Figure 1 A schematic diagram illustrating an example environment in which an apparatus for optical communication according to an embodiment of the present invention may be implemented is illustrated.

[0025] Figure 2 A schematic block diagram of an apparatus for optical communication according to an embodiment of the present invention is illustrated.

[0026] Figure 3 A schematic optical path diagram of a device for optical communication according to an embodiment of the present invention is illustrated.

[0027] Figure 4A A schematic cross-sectional view of a first dual-core optical fiber according to an embodiment of the present invention is illustrated.

[0028] Figure 4B A schematic cross-sectional view of a second dual-core optical fiber according to an embodiment of the present invention is illustrated.

[0029] Figure 5 A schematic diagram illustrating the position of a light spot in a fine tracking unit according to an embodiment of the present invention is shown.

[0030] Figure 6 A schematic diagram illustrating a process in which a control unit of an apparatus for optical communication calibrates an optical axis of the apparatus according to an embodiment of the present invention is shown.

[0031] Figure 7 A schematic diagram illustrating a process in which a control unit of an apparatus for optical communication calibrates an optical axis of the apparatus according to another embodiment of the present invention is shown.

[0032] Figure 8 A schematic diagram of a process of calibrating a second optical axis during the process of calibrating an optical axis according to an embodiment of the present invention is illustrated.

[0033] Fig. 9 A schematic diagram of a process of calibrating a first optical axis during the process of calibrating an optical axis according to an embodiment of the present invention is illustrated.

[0034] In the various drawings, the same or corresponding reference numerals represent the same or corresponding parts. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0036] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects.

[0037] As described above, the disadvantages of conventional devices for optical communication are that it takes a long time to calibrate the optical axis of the device and the calibration accuracy is low.

[0038] As described above, conventionally, in order to calibrate the optical axis of a device for optical communication, it is necessary to repeatedly detect (for example, by using a photoelectric detector (APD)) the intensity of the signal light received by the device and adjust the angle of the relevant optical device of the device accordingly, resulting in a long calibration process and low calibration accuracy. In addition, this calibration method is only applicable to the case where the device has scanned another device with which it will conduct optical communication. When the device has not scanned another device, the optical axis cannot be calibrated, which will bring great inconvenience to the calibration of the device, especially when the device is a satellite-borne device set on a satellite and the optical axis cannot be manually calibrated.

[0039] In addition, for satellite-borne devices, during the satellite launch process, the device will experience a large degree of turbulence and stress, resulting in a large deviation of the device's optical axis relative to the preset direction, which will cause the device's on-orbit calibration process to be very long and the accuracy to be very low. In addition, the wavelength of the calibration light emitted by the device's transmitting unit is usually close to the wavelength of the signal light received by the device's receiving unit from another device, and the transmitting optical axis of the transmitting unit emitting the calibration light is coaxial with the receiving optical axis of the receiving unit receiving the signal light, which will also result in a low transmit-receive isolation of the device.

[0040] In order to at least partially solve one or more of the above problems and other potential problems, an exemplary embodiment of the present invention provides a device for optical communication. In the device for optical communication, the optical axis of the device for optical communication is calibrated based on the positions of the light spots formed by the first calibration light, the second calibration light, and the second signal light detected by the precision tracking unit, so that the efficiency and accuracy of calibrating the optical axis of the device can be improved, thereby improving the communication quality of the device for optical communication.

[0041] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Figure 1 A schematic diagram illustrating an example environment in which an apparatus for optical communication according to an embodiment of the present invention may be implemented is illustrated. Figure 1 The illustrated example environment may represent an optical communication environment, which illustrates a scenario in which an apparatus 114 for optical communication disposed on a satellite 112 performs optical communication with any of corresponding apparatuses 122, 124, 126, etc., for optical communication located on the ground. During the launch or operation of the satellite 112, the apparatus 114 disposed on the satellite 112 may experience a large degree of turbulence and stress, thereby causing the optical axis of the apparatus 114 to have a large deviation relative to a preset direction. Therefore, before the apparatus 114 performs signal light transmission with any of corresponding apparatuses 122, 124, 126, etc., the optical axis of the apparatus 114 needs to be calibrated to ensure the communication quality of the optical communication.

[0042] The following will take the device 114 as an example to describe the device for optical communication according to the embodiment of the present invention. However, it should be understood that the embodiment of the present invention can be applied to Figure 1 Other optical communication environments and other devices for optical communication shown, for example, terrestrial optical communication environments, or terrestrial devices (for example, Figure 1 Corresponding devices 122, 124, 126, ...) and so on.

[0043] Figure 2 FIG. 1 is a schematic block diagram of an apparatus for optical communication according to an embodiment of the present invention. In some embodiments, Figure 2The device shown may be a satellite-borne device, for example, Figure 1 The device 114 shown is disposed on the satellite 112. In other embodiments, Figure 2 The device shown may be a ground-mounted device. Figure 2 The device shown includes a transmitting unit 210 , a receiving unit 220 , a transceiver unit 230 , a precision tracking unit 240 , and a control unit 250 .

[0044] The transmitting unit 210 includes a first dual-core optical fiber, and the first dual-core optical fiber includes a first core and a second core. The first core is configured to transmit a first signal light, and the second core is configured to transmit a first calibration light. In some embodiments, the spacing between the first core and the second core of the first dual-core optical fiber can be greater than the diameter of the first core and the diameter of the second core. For example, the spacing can be the distance between the center of the first core and the center of the second core. Thereby, the first calibration light can be prevented from being coupled into the first core, thereby preventing crosstalk between the first signal light and the first calibration light.

[0045] In some embodiments, the wavelength of the first signal light may be different from the wavelength of the first calibration light. In some embodiments, the first signal light may be light carrying communication information, and the first calibration light may be light not carrying communication information. Due to the setting of the dual-core optical fiber, the first calibration light may be in a fixed angle relationship with the first signal light (to be further described in the examples below) to indicate the propagation direction of the first signal light (i.e., the direction of the optical axis).

[0046] The receiving unit 220 includes a second dual-core optical fiber, and the second dual-core optical fiber includes a third core and a fourth core. The third core is configured to receive a second signal light, and the fourth core is configured to transmit a second calibration light, where the second signal light comes from another device (e.g., Figure 1 Any of the corresponding devices 122, 124, 126, etc. shown).

[0047] In some embodiments, the spacing between the third core and the fourth core may be greater than the diameter of the third core and the diameter of the fourth core. For example, the spacing may be the distance between the center of the third core and the center of the fourth core. Making the distance greater than the diameters of the third core and the fourth core may make the distance between the third core and the fourth core greater than the numerical apertures of the third core and the fourth core. Thus, the second calibration light may be prevented from being coupled into the third core, thereby preventing crosstalk between the second signal light and the second calibration light.

[0048] In some embodiments, the wavelength of the second signal light may be different from the wavelength of the second calibration light. In some embodiments, the second signal light may be light carrying communication information, and the second calibration light may be light not carrying communication information. Due to the setting of the dual-core optical fiber, the second calibration light may be used to indicate whether it is at a predetermined relative angle to the current propagation direction (i.e., the optical axis direction) of the second signal light, i.e., to indicate the optical axis direction of the current second signal light.

[0049] In addition, in some embodiments, the wavelength of the first signal light may be different from the wavelength of the second signal light. Thus, the device for optical communication according to the embodiment of the present invention may have a higher transmit-receive isolation.

[0050] The transceiver unit 230 is configured to send the first signal light to another device, transmit the first calibration light and the second calibration light to the fine tracking unit, receive the second signal light from another device and transmit the second signal light to the fine tracking unit and the receiving unit.

[0051] The fine tracking unit 240 is configured to detect a first position of a first light spot formed by the first calibration light in the fine tracking unit 240, a second position of a second light spot formed by the second calibration light in the fine tracking unit 240, and a third position of a third light spot formed by the second signal light in the fine tracking unit 240. In some embodiments, the first position, the second position, and the third position may be positions in a focal plane of a fine tracking lens assembly in the fine tracking unit 240, and are positions of the centroids of the corresponding light spots.

[0052] The control unit 250 is configured to calibrate the optical axis of the device based on at least one of the first position, the second position, and the third position. Since the first calibration light, the second calibration light, and the second signal light respectively formed in the precision tracking unit 240 at the first position, the second position, and the third position are separated from each other by using the first dual-core optical fiber and the second dual-core optical fiber as described above, the control unit 250 can use a simple algorithm to accurately calibrate the optical axis of the device, thereby improving the efficiency and accuracy of the calibration.

[0053] According to the above-mentioned device of an embodiment of the present invention, the optical axis of the device for optical communication is calibrated based on the positions of the light spots respectively formed by the first calibration light, the second calibration light and the second signal light detected by the precision tracking unit 240, so that the efficiency and accuracy of calibrating the optical axis of the device can be improved, thereby improving the communication quality of the device for optical communication.

[0054] The following reference Figure 3 The schematic optical path diagram of the device shown is used to further describe the embodiment of the present invention. Figure 3 A schematic optical path diagram of a device for optical communication according to an embodiment of the present invention is illustrated. Figure 3The optical path diagram shows Figure 2 The transmitting unit 210, the receiving unit 220, the transceiver unit 230, and the precision tracking unit 240. Figure 3 The control unit 250 is not shown, but it should be understood that the control unit 250 can be coupled to the above units and can be implemented by any controller capable of implementing calibration according to the embodiments of the present invention. Figure 3 In the figure, the solid lines between the optical elements represent the light path, and the dotted arrows between the solid lines represent the propagation direction of the light in the corresponding light path portion.

[0055] like Figure 3 As shown, the transmitting unit 210 may include a first double-core optical fiber 211, a transmitting mirror group 212, and a first fast-reflecting mirror 213. The first core of the first double-core optical fiber 211 may transmit a first signal light S1, and the second core of the first double-core optical fiber 211 may transmit a first calibration light CA1. The transmitting mirror group 212 may be optically coupled to the first double-core optical fiber 211. The first fast-reflecting mirror 213 may be optically coupled to the transmitting mirror group 212.

[0056] The transceiver unit 230 may include a first beam splitter 231 optically coupled to the first quick-reflection mirror 213, and further include a second quick-reflection mirror 232, a first reflector 233, an optical antenna 234, a pyramid 235, a second beam splitter 236, and a second reflector 237. In some embodiments, the transceiver unit 230 may further include an optical filter 238. In some embodiments, the optical filter 238 may be optically coupled in the optical path between the first beam splitter 231 and the second beam splitter 236, such as Figure 3 In some other embodiments, the filter 238 can be optically coupled to the light path between the first beam splitter 231 and the cone 235 .

[0057] The receiving unit 220 may include a receiving mirror group 222 and a second double-core optical fiber 221. The receiving mirror group 222 is optically coupled to the second beam splitter 236 of the transceiver unit 230. The second double-core optical fiber 221 may be optically coupled to the receiving mirror group 222. The third core of the second double-core optical fiber 221 is used to receive the second signal light S2, and the fourth core of the second double-core optical fiber 221 is used to transmit the second calibration light CA2.

[0058] The fine tracking unit 240 may include a fine tracking lens group 242 and a camera 241. The fine tracking lens group 242 may be optically coupled to the second reflector 237 of the transceiver unit 230. The camera 241 may be optically coupled to the fine tracking lens group 242.

[0059] It should be understood that Figure 3 The above optical path structure is only an example, and other optical path structures can be set as needed. Figure 3The off-axis reflective antenna shown is replaced with a coaxial antenna, a transmissive antenna, or a combination thereof.

[0060] exist Figure 3 In the example, the first signal light S1 can be sent to another device via the first core of the first double-core optical fiber 211, the transmitting mirror group 212, the first fast reflection mirror 213, the first beam splitter 231, the second fast reflection mirror 232, the first reflection mirror 233, and the optical antenna 234 in sequence.

[0061] The first calibration light CA1 may be transmitted to the fine tracking unit 240 in sequence via the second core of the first double-core optical fiber 211, the emitting mirror group 212, the first fast mirror 213, the first beam splitter 231, the cone 235, the first beam splitter 231, (and the filter 238), the second beam splitter 236, and the second reflecting mirror 237. For example, the first calibration light CA1 is transmitted to the camera 241 through the fine tracking mirror group 242 of the fine tracking unit 240.

[0062] The second signal light S2 may be sequentially transmitted to the receiving unit 220 via the optical antenna 234, the first reflector 233, the second fast mirror 232, the first beam splitter 231, (and the filter 238) the second beam splitter 236, and further transmitted to the fine tracking unit 240 via the second reflector 237 optically coupled to the second beam splitter 236. Thus, the second signal light S2 may be transmitted to the receiving unit 220 and simultaneously transmitted to the fine tracking unit 240. For example, the second signal light S2 is transmitted to the camera 241 through the fine tracking mirror group 242 of the fine tracking unit 240.

[0063] The second calibration light CA2 is transmitted from the fourth core of the second dual-core optical fiber 221 of the receiving unit 220 to the fine tracking unit 240 via the receiving mirror group 222, in sequence, via the second beam splitter 236, (and the filter 238) the first beam splitter 231, the cone 235, the first beam splitter 231, (and the filter 238) the second beam splitter 236, and the second reflector 237. For example, the second calibration light CA2 is transmitted to the camera 241 through the fine tracking mirror group 242 of the fine tracking unit 240.

[0064] exist Figure 3In the example, the first dual-core optical fiber 211 can be located at the focal plane of the transmitting lens group 212, the second dual-core optical fiber 221 can be located at the focal plane of the receiving lens group 222, and the camera 241 can be located at the focal plane of the precision tracking lens group 242. Therefore, on the left side of the transmitting lens group 212, the receiving lens group 222, and the precision tracking lens group 242, there are collimated beams of corresponding light, and on the right side, there are focused beams of corresponding light. For the case where one side of the lens group is two collimated beams and the other side of the lens group is the corresponding two focused beams, the relative angle between the two collimated beams and the spacing between the corresponding two focused beams at the focal plane have a corresponding relationship as shown in the following equations (1) and (2).

[0065] θ x = d x / F (1) θ y = d y / F (2) In the above equations (1) and (2), F represents the focal length of the lens group, θ x and θ y Respectively represent the relative angles of the two collimated beams along the x-axis and y-axis of the mirror assembly coordinate system. The mirror assembly coordinate system can be parallel to Figure 3 Schematic diagram of the coordinate system in the plane. x and d y They represent the relative distances of the two collimated beams in the focal plane of the lens assembly along the x-axis and y-axis of the focal plane coordinate system. The focal plane coordinate system can be perpendicular to Figure 3 The above relative angles and relative distances are directional (i.e., they can be positive or negative).

[0066] The above formula (1) and formula (2) can be applied to the process of calibrating the optical axis of the device according to the embodiment of the present invention. FIG. 4A to FIG. 9 An example of calibrating the optical axis of a device according to an embodiment of the present invention is described. Figure 4A and Figure 4B Schematic cross-sectional views of a first double-core optical fiber 211 and a second double-core optical fiber 221 according to embodiments of the present invention are respectively illustrated. Figure 4A and Figure 4B The cross-section shown is taken perpendicular to Figure 3 The diagram is taken from the plane of the schematic diagram.

[0067] like Figure 4A As shown, the distance between the first core C1 and the second core C2 of the first double-core optical fiber 211 is d 发射 , spacing d 发射 It can be achieved by (d x发射 ,d y发射) to indicate. x发射 and d y发射 They can respectively represent: in the focal plane of the emitting mirror group on the right side of the emitting mirror group 212, the relative distance between the first signal light S1 and the first calibration light CA1 along the x-axis direction and the y-axis direction of the focal plane coordinate system of the emitting mirror group. 发射 (d x发射 ,d y发射 ) is substituted into the above equations (1) and (2) to obtain: On the left side of the transmitting mirror assembly 212, the relative angles of the first signal light S1 and the first calibration light CA1 along the x-axis direction and the y-axis direction of the transmitting mirror assembly coordinate system are θ respectively. x发射 = d x发射 / F 发射 ,θ y发射 = d y发射 / F 发射 , F 发射 represents the focal length of the transmitting lens assembly 212.

[0068] like Figure 4B As shown, the distance between the third core C3 and the fourth core C4 of the second double-core optical fiber 221 is d 接收 , spacing d 接收 It can be achieved by (d x接收 ,d y接收 ) to indicate. x接收 and d y接收 They can respectively represent: in the focal plane of the receiving lens group on the right side of the receiving lens group 222, the relative distance of the desired second signal light S2 and the second calibration light CA2 along the x-axis direction and the y-axis direction of the focal plane coordinate system of the receiving lens group. 接收 (d x接收 ,d y接收 ) is substituted into the above equations (1) and (2) to obtain: On the left side of the receiving mirror assembly 222, the relative angles of the desired second signal light S2 and the second calibration light CA2 along the x-axis direction and the y-axis direction of the receiving mirror assembly coordinate system are θ respectively. x接收 = d x接收 / F 接收 ,θ y接收 = d y接收 / F 接收 , F 接收 represents the focal length of the receiving lens assembly 222.

[0069] The above θ x发射 ,θ y发射 ,θ x接收 and θ y接收It is insensitive to the bumps and stresses experienced by the device, and therefore, can be used to calibrate the optical axis of the device. In some embodiments, the optical axis of the device may include a first optical axis for the transmission of the first signal light S1 in the device, and a second optical axis for the transmission of the second signal light S2 in the device. In some embodiments, the control unit 250 calibrates the optical axis so that: in the transceiver unit 230, the first optical axis overlaps with the second optical axis. For example, the calibration makes Figure 3 In the optical path between the second fast reflection mirror 232 and the receiving lens assembly 222 , the first optical axis overlaps with the second optical axis.

[0070] Since the relative angles of the first calibration light CA1, the second calibration light CA2, and the second signal light S2 do not change when they are transmitted in the transceiver unit 230, the actual relative angle between them can be determined by using the relative positions of the light spots formed by them in the precision tracking unit 240, and the first optical axis and the second optical axis can be calibrated according to the deviation between the actual relative angle and the predetermined relative calibration. Figure 5 FIG. 2 is a schematic diagram showing the position of the light spot in the fine tracking unit 240 according to an embodiment of the present invention. Figure 5 As shown, the first calibration light CA1 is incident on the first position P1 (p x1 ,p y1 ), the second calibration light CA2 is incident on the second position P2 (p x2 , p y2 ), the second signal light S2 is incident on the third position P3 (p x3 , p y3 ). The first position P1 (p x1 , p y1 )、The second position P2(p x2 , p y2 ), and the third position P3 (p x3 , p y3 ) are all positions in the camera coordinate system, that is, positions in the coordinate system in the focal plane on the right side of the precision tracking lens group. It should be understood that the above coordinate systems related to positions can be the same or different and can be converted to each other, and the above coordinate systems related to relative angles can be the same or different and can be converted to each other.

[0071] Figure 6 The diagram shows a process in which the control unit 250 of the device for optical communication calibrates the optical axis of the device according to an embodiment of the present invention. Figure 6The example corresponds to a "non-real-time" calibration situation. "Non-real-time" calibration may refer to calibration performed in a non-optical communication stage when the device does not perform optical communication. In this case, there is no second signal light S2, and therefore there is no third position of the second signal light S2 in the fine tracking unit 240. The control unit 250 may use the first calibration light CA1 to perform calibration at the first position P1 (p x1 , p y1 ), and the second position P2 (p x2 , p y2 ) is performed as follows to calibrate the optical axis of the device.

[0072] At block 602, a first position P1 (p x1 , p y1 ) and the second position P2 (p x2 , p y2 ). For example, the first relative distance can be expressed as △d1(d 1x =p x1 -p x2 , d 1y = p y1 -p y2 ).

[0073] At block 604, based on the first relative distance Δd1 and the focal length F of the fine tracking lens group in the fine tracking unit 精跟 , to obtain the first relative angle between the first calibration light and the second calibration light. For example, the first relative angle θ1 (θ 1x = d 1x / F 精跟 , θ 1y = d1 / F 精跟 ). The first relative angle may represent an actual relative angle between the first calibration light CA1 and the second calibration light CA2.

[0074] At block 606, the first relative angle may be compared with a first predetermined relative angle to obtain a first comparison result. In some embodiments, the first predetermined relative angle may be determined based on the following items: the spacing d between the first core C1 and the second core C2 发射 , the distance d between the third core C3 and the fourth core C4 接收 , the focal length F of the transmitting lens group 212 in the transmitting unit 210 发射 , and the focal length F of the receiving lens assembly 222 in the receiving unit 220 接收 For example, the first predetermined relative angle may be based on the above θ x发射 ,θ y发射 ,θx接收 and θ y接收 The first predetermined relative angle may represent an expected relative angle between the first calibration light CA1 and the second calibration light CA2.

[0075] At block 608, the tilt angle of at least one fast mirror in the device can be adjusted based on the first comparison result to calibrate the first optical axis and the second optical axis. In some embodiments, the calibration of the first optical axis and the second optical axis can be completed by adjusting the first relative angle obtained at block 604 to the first predetermined relative angle in block 606.

[0076] The above describes the "non-real-time" calibration of the device. When the device performs "real-time" calibration, the first optical axis and the second optical axis of the device can also be calibrated based on the relationship shown in the above formulas (1) and (2). "Real-time" calibration can refer to calibration performed during the optical communication stage of the device, for example, after the device scans another device to communicate with it.

[0077] Figure 7 FIG. 1 is a schematic diagram showing a process in which the control unit 250 of the device for optical communication calibrates the optical axis of the device according to another embodiment of the present invention. Figure 7 The example corresponds to the above-mentioned “real-time” calibration situation. In this case, the control unit 250 can use the first calibration light CA1 to calibrate the first position P1 (p x1 , p y1 ), the second calibration light CA2 is at a second position P2 (p x2 , p y2 ), and a third position P3 (p x3 , p y3 ) is performed as follows to calibrate the optical axis of the device.

[0078] At block 702, a second position P2 (p x2 , p y2 ) and the third position P3 (p x3 , p y3 ). For example, the second relative distance can be expressed as △d2(d 2x =p x2 -p x3 , d 2y = p y2 -p y3 ).

[0079] At block 704, the second optical axis may be calibrated based on the second relative distance. In some embodiments, the second optical axis may be calibrated by obtaining the actual relative angle between the second signal light and the second calibration light based on equations (1) and (2) above (to be further described in the examples below).

[0080] At block 706, a third relative distance between the first position and the third position after the second optical axis is calibrated may be determined. Here, since the second optical axis is calibrated at block 704, the transmission direction of the second signal light may change after the calibration. In addition, since the direction of the second optical axis is adjusted by Figure 3 The first position and the third position may be adjusted relative to each other by adjusting the inclination angle of the second quick-reflection mirror 232. The adjustment of the inclination angle of the second quick-reflection mirror 232 will simultaneously change the direction of the first optical axis. Therefore, after the second optical axis is calibrated, the first position and the third position may be adjusted relative to each other. Figure 5 However, for the sake of convenience, P1 (p x1 , p y1 ) to indicate the current first position, P3 (p x3 , p y3 ) to represent the current third position, to illustrate the third relative distance. For example, the third relative distance obtained as above can be expressed as △d3(d 3x =p x1 -p x3 , d 3y = p y1 -p y3 ).

[0081] At block 708, the first optical axis may be calibrated based on the third relative distance. In some embodiments, the first optical axis may be calibrated by obtaining an actual relative angle between the first calibration light and the second signal light based on equations (1) and (2) above (to be further described in the examples below).

[0082] Figure 8 A schematic diagram of a process of calibrating a second optical axis during the process of calibrating an optical axis according to an embodiment of the present invention is illustrated. Figure 8 The process shown corresponds to Figure 7 In block 704. Figure 8 As shown, the control unit 250 can calibrate the second optical axis as follows.

[0083] At block 802, based on a second relative distance Δd2 (d 2x , d 2y ), and the focal length F of the fine-tracking lens group in the fine-tracking unit 精跟, to obtain the second relative angle between the second calibration light and the second signal light. For example, the second relative angle θ2 (θ 2x = d 2x / F 精跟 , θ 2y = d 2y / F 精跟 ). The second relative angle may represent an actual relative angle between the second calibration light CA2 and the second signal light S2.

[0084] At block 804, the second relative angle may be compared with a second predetermined relative angle to obtain a second comparison result. In some embodiments, the second predetermined relative angle may be determined based on the following items: the spacing d between the third core C3 and the fourth core C4 of the second dual-core optical fiber 221 in the receiving unit 220; 接收 , and the focal length F of the receiving lens assembly 222 in the receiving unit 220 接收 The second predetermined relative angle may represent an expected relative angle between the second calibration light CA2 and the second signal light S2.

[0085] At block 806, the tilt angle of the fast mirror (eg, the second fast mirror 232) in the transceiver unit 230 may be adjusted based on the second comparison result to adjust the second relative angle to a second predetermined relative angle (eg, the second predetermined relative angle corresponds to (θ x接收 ,θ y接收 )). Thus, the second optical axis can be calibrated quickly and accurately.

[0086] After completing the calibration of the second optical axis, the first optical axis can be calibrated. For example, the calibration of the first optical axis can be performed by adjusting Figure 3 The adjustment of the tilt angle (for example, the pitch angle) of the first fast mirror 213 in the optical system is performed. The adjustment of the tilt angle of the first fast mirror 213 will only change the direction of the first optical axis, but will not change the direction of the second optical axis. Therefore, in the above embodiment, the second optical axis is first calibrated, and then the first optical axis is calibrated. It should be understood that in the actual optical path structure and Figure 3 As shown, it is also possible to calibrate the first optical axis first and then the second optical axis, or to calibrate both at the same time.

[0087] Fig. 9 A schematic diagram of a process of calibrating a first optical axis during the process of calibrating an optical axis according to an embodiment of the present invention is illustrated. Fig. 9 The process shown corresponds to Figure 7 In block 708. Fig. 9 As shown, the control unit 250 can calibrate the first optical axis as follows.

[0088] At block 902, based on a third relative distance Δd3 (d 3x ,d 3y ), and the focal length F of the fine-tracking lens group in the fine-tracking unit 精跟 , to obtain the third relative angle between the first calibration light and the second signal light. For example, the third relative angle θ3 (θ 3x = d 3x / F 精跟 , θ 2y = d 3y / F 精跟 ). The third relative angle may represent an actual relative angle between the first calibration light CA1 and the second signal light S2.

[0089] At block 904, the third relative angle may be compared with a third predetermined relative angle to obtain a third comparison result. In some embodiments, the third predetermined relative angle may be determined based on the following items: the spacing d between the first core C1 and the second core C2 of the first dual-core optical fiber 211 in the transmitting unit 210; 发射 , and the focal length F of the transmitting lens group 212 in the transmitting unit 210 发射 The third predetermined relative angle may represent an expected relative angle between the first calibration light CA1 and the second signal light S2.

[0090] In this embodiment, since it is expected that the first optical axis and the second optical axis of the first signal light S1 and the second signal light S2 in the transceiver unit 230 are calibrated to overlap with each other, and when the relative angle between the first calibration light CA1 and the second signal light S2 is equal to the relative angle between the first calibration light CA1 and the first signal light S1, it can be determined that the first optical axis and the second optical axis overlap, and therefore, the above-mentioned third comparison result can be used to calibrate the first optical axis.

[0091] At block 906, the tilt angle of the fast reflection mirror (eg, the first fast reflection mirror 213) in the transmitting unit 210 may be adjusted based on the third comparison result to adjust the third relative angle to a third predetermined relative angle (eg, the third predetermined relative angle corresponds to (θ x发射 ,θ y发射 )). Thus, the first optical axis can be calibrated quickly and accurately.

[0092] It should be understood that the optical path diagrams, relative positions and relative angles shown in the above embodiments are merely examples, and optical path diagrams, relative positions and relative angles different from those described above may be set as needed.

[0093] The various processes and processing described above, such as methods, may be performed at a computing device. The computing device includes, for example: at least one processor (at least one graphics processor and at least one central processing unit); and a memory connected to the at least one processor in communication; wherein the memory stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor. In some embodiments, the method may be implemented as a computer software program or program product, which is tangibly contained in a machine-readable medium. In some embodiments, part or all of the computer program may be loaded and / or installed on a computing device via a read-only memory (ROM) and / or a communication unit. When the computer program is loaded into a random-access memory (RAM) and executed by a GPU and a CPU, one or more actions of the method described above may be performed.

[0094] The present invention may be a method, an apparatus, a system and / or a computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions for executing various aspects of the present invention. The computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof.

[0095] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. Various aspects of the present invention are described herein with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each box of the flowchart and / or block diagram, and the combination of boxes in the flowchart and / or block diagram, can be implemented by computer-readable program instructions.

[0096] These computer-readable program instructions can be provided to a central processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the central processing unit of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0097] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of a module, program segment or instruction includes one or more executable instructions for realizing the logical function of the specification. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the function involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be realized by a special hardware-based system that performs the function or action of the specification, or can be realized by a combination of special hardware and computer instructions.

[0098] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0099] The above specific implementations do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made according to design requirements and other factors.

Claims

1. A device for optical communication, characterized in that: include: A transmitting unit, comprising a first double-core optical fiber, wherein the first double-core optical fiber comprises a first core and a second core, wherein the first core is configured to transmit a first signal light, and the second core is configured to transmit a first calibration light; A receiving unit, comprising a second double-core optical fiber, wherein the second double-core optical fiber comprises a third core and a fourth core, wherein the third core is configured to receive a second signal light, and the fourth core is configured to transmit a second calibration light, wherein the second signal light comes from another device in optical communication with the device; a transceiver unit configured to send the first signal light to the other device, transmit the first calibration light and the second calibration light to a precision tracking unit, receive the second signal light from the other device and transmit the second signal light to the precision tracking unit and the receiving unit; A fine tracking unit, configured to detect a first position of a first light spot formed by the first calibration light in the fine tracking unit, a second position of a second light spot formed by the second calibration light in the fine tracking unit, and a third position of a third light spot formed by the second signal light in the fine tracking unit; as well as A control unit is configured to calibrate the optical axis of the device based on at least one of the first position, the second position, and the third position.

2. The device according to claim 1, characterized in that The optical axis includes: a first optical axis for transmission of the first signal light in the device, and a second optical axis for transmission of the second signal light in the device, and The calibration is performed so that: in the transceiver unit, the first optical axis overlaps with the second optical axis.

3. The device according to claim 2, characterized in that In a non-optical communication stage where the device does not perform optical communication, the control unit is configured to calibrate the optical axis of the device as follows: determining a first relative distance between the first position and the second position; Obtaining a first relative angle between the first calibration light and the second calibration light based on the first relative distance and the focal length of the fine tracking lens group in the fine tracking unit; comparing the first relative angle with a first predetermined relative angle to obtain a first comparison result; as well as Based on the first comparison result, the tilt angle of at least one fast reflection mirror in the device is adjusted to calibrate the first optical axis and the second optical axis.

4. The device according to claim 3, characterized in that The first predetermined relative angle is determined based on: The distance between the first core and the second core, the distance between the third core and the fourth core, the focal length of the transmitting mirror assembly in the transmitting unit, and the focal length of the receiving mirror assembly in the receiving unit.

5. The device according to claim 2, characterized in that During the optical communication stage of the device performing optical communication, the control unit is configured to calibrate the optical axis of the device as follows: determining a second relative distance between the second position and the third position; calibrating the second optical axis based on the second relative distance; determining a third relative distance between the first position and the third position after calibrating the second optical axis; as well as The first optical axis is calibrated based on the third relative distance.

6. The device according to claim 5, characterized in that The control unit is configured to calibrate the second optical axis based on the second relative distance as follows: Obtaining a second relative angle between the second calibration light and the second signal light based on the second relative distance and the focal length of the fine tracking lens group in the fine tracking unit; comparing the second relative angle with a second predetermined relative angle to obtain a second comparison result; as well as Based on the second comparison result, the tilt angle of the fast reflection mirror in the transceiver unit is adjusted to adjust the second relative angle to the second predetermined relative angle.

7. The device according to claim 6, characterized in that The control unit is configured to calibrate the first optical axis based on the third relative distance as follows: Based on the third relative distance and the focal length of the fine tracking lens group in the fine tracking unit, a third relative angle between the first calibration light and the second signal light after the second optical axis is calibrated is obtained; comparing the third relative angle with a third predetermined relative angle to obtain a third comparison result; as well as Based on the third comparison result, the tilt angle of the fast reflection mirror in the transmitting unit is adjusted to adjust the third relative angle to the third predetermined relative angle.

8. The device according to claim 7, characterized in that The second predetermined relative angle is determined based on the following items: the distance between the third core and the fourth core, and the focal length of the receiving lens group in the receiving unit, and The third predetermined relative angle is determined based on: a distance between the first core and the second core, and a focal length of a transmitting mirror group in the transmitting unit.

9. The device according to claim 1, characterized in that The transmitting unit also includes: a transmitting mirror assembly optically coupled to the first double-core optical fiber; and A first fast reflection mirror is optically coupled to the transmitting mirror group.

10. The device according to claim 9, characterized in that The transceiver unit includes: a first beam splitter, a second fast-reflecting mirror, a first reflector, an optical antenna, a pyramid, a second beam splitter, and a second reflector. The first signal light is sent to the other device via the first core, the transmitting mirror group, the first fast reflection mirror, the first beam splitter, the second fast reflection mirror, the first reflection mirror, and the optical antenna in sequence. The first calibration light is transmitted to the precision tracking unit via the second core, the transmitting mirror group, the first fast mirror, the first beam splitter, the cone, the first beam splitter, the second beam splitter, and the second reflector in sequence. The second signal light is transmitted to the receiving unit via the optical antenna, the first reflector, the second fast reflector, the first beam splitter, and the second beam splitter in sequence, and is also transmitted to the fine tracking unit via the second reflector optically coupled to the second beam splitter, and The second calibration light is transmitted from the receiving unit to the fine tracking unit via the second beam splitter, the first beam splitter, the pyramid, the first beam splitter, the second beam splitter, and the second reflector in sequence.

11. The device according to claim 10, characterized in that The transceiver unit also includes: A filter is optically coupled in a light path between the first beam splitter and the second beam splitter, or optically coupled in a light path between the first beam splitter and the cone.

12. The device according to claim 10, characterized in that The receiving unit also includes: a receiving mirror set, optically coupled to the second beam splitter, The second double-core optical fiber is optically coupled to the receiving mirror assembly.

13. The device according to claim 12, characterized in that The fine heel unit comprises: a precision mirror assembly optically coupled to the second reflector; and A camera is optically coupled to the precision mirror assembly.

14. The device according to any one of claims 1 to 13, characterized in that The distance between the first core and the second core is greater than the diameter of the first core and the diameter of the second core, and A distance between the third core and the fourth core is greater than a diameter of the third core and a diameter of the fourth core.

15. The device according to any one of claims 1 to 13, characterized in that The wavelength of the first signal light is different from the wavelength of the second signal light and is different from the wavelength of the first calibration light, and The wavelength of the second signal light is different from the wavelength of the second calibration light.

16. The device according to any one of claims 1 to 13, characterized in that The device is an onboard device arranged on a satellite.

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