Device for optical communication

Abstract

The present invention relates to a device for optical communication. The device includes: a transmitting unit, including a first dual-core optical fiber, where its first core transmits a first signal light and its second core transmits a first calibration light; a receiving unit, including a second dual-core optical fiber, where its third core receives a second signal light and its fourth core transmits a second calibration light; a transceiver unit, configured to send the first signal light to another device, transmit the first and second calibration lights to a 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; 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. The present invention can achieve a device for optical communication that can calibrate the optical axis efficiently and accurately.

Description

Technical Field

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

[0002] During the process of optical communication, the optical axis of the apparatus for optical communication needs to be in a preset direction so that the signal light is aligned with the corresponding optical elements in the apparatus, thereby enabling the apparatus to have a high signal-to-noise ratio. However, for example, in the case of large bumps or stresses during the transportation of the apparatus for optical communication, the optical axis of the apparatus may deviate from the preset direction, resulting in a poor signal-to-noise ratio during the optical communication process of the apparatus and poor optical communication quality. Therefore, it is necessary to calibrate the optical axis of the apparatus. Generally, after the apparatus scans another apparatus with which it will perform optical communication (for example, during the link establishment process), the apparatus adjusts the tilt angle of the corresponding optical device of the apparatus according to the intensity of the signal light received from the other apparatus by detecting the intensity of the signal light received from the other apparatus, and repeats this process to calibrate the optical axis of the apparatus. However, this calibration process takes a long time and cannot accurately calibrate the optical axis of the apparatus to the preset direction.

[0003] In summary, the deficiencies of the traditional apparatus for optical communication are as follows: the time for calibrating the optical axis of the apparatus is long, and the calibration accuracy is low. Summary of the Invention

[0004] The present invention provides an apparatus for optical communication that can efficiently and accurately calibrate the optical axis.

[0005] According to a first aspect of the present invention, there is provided an optical communication device. The device includes: a transmitting unit including a first dual-core optical fiber, the first dual-core optical fiber including a first core and a second core, the first core being configured to transmit a first signal light, and the second core being configured to transmit a first calibration light; a receiving unit including a second dual-core optical fiber, the second dual-core optical fiber including a third core and a fourth core, the third core being configured to receive a second signal light, and the fourth core being configured to transmit a second calibration light, the second signal light coming from another device that performs optical communication with the device; a transceiver unit configured to send the first signal light to the another device, transmit the first calibration light and the second calibration light to a fine tracking unit, receive the second signal light from the 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 a first spot formed by the first calibration light in the fine tracking unit, a second position of a second spot formed by the second calibration light in the fine tracking unit, and a third position of a third spot formed by the second signal light in the fine tracking unit; 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.

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

[0007] In some embodiments, in a non-optical communication phase 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 a focal length of a 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 an inclination angle of at least one fast steering 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 pitch between the first core and the second core, a pitch between the third core and the fourth core, a focal length of a transmitting lens group in the transmitting unit, and a focal length of a receiving lens group in the receiving unit.

[0009] In some embodiments, during the optical communication phase 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 steering 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: obtain a third relative angle between the first calibration light and the second signal light after calibrating the second optical axis based on the third relative distance and the focal length of the fine tracking lens group in the fine tracking unit; compare the third relative angle with a third predetermined relative angle to obtain a third comparison result; and adjust the tilt angle of the fast steering mirror in the transmitting unit based on the third comparison result 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: the spacing 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 the following: the spacing between the first core and the second core, and the focal length of the transmitting lens group in the transmitting unit.

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

[0014] In some embodiments, the transceiver unit includes: a first beam splitter, a second fast steering mirror, a first reflector, an optical antenna, a corner cube, a second beam splitter, and a second reflector, wherein the first signal light is sequentially transmitted to the other device via the first core, the transmitting mirror group, the first fast steering mirror, the first beam splitter, the second fast steering mirror, the first reflector, and the optical antenna, the first calibration light is sequentially transmitted to the fine tracking unit via the second core, the transmitting mirror group, the first fast steering mirror, the first beam splitter, the corner cube, the first beam splitter, the second beam splitter, and the second reflector, the second signal light is sequentially transmitted to the receiving unit via the optical antenna, the first reflector, the second fast steering mirror, the first beam splitter, and the second beam splitter, 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 to the fine tracking unit from the receiving unit via the second beam splitter, the first beam splitter, the corner cube, the first beam splitter, the second beam splitter, and the second reflector.

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

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

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

[0018] In some embodiments, the distance between the first core and the second core is greater than the diameters of the first core and the second core, and the distance between the third core and the fourth core is greater than the diameters of the third core and 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 a spaceborne device disposed on a satellite.

[0021] It should be understood that the beneficial effects of the present invention are as follows: By calibrating the optical axis of the device 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 fine 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 content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used 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] In conjunction with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present invention will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements.

[0024] Figure 1 FIG. is a schematic diagram of an exemplary environment in which a device for optical communication according to an embodiment of the present invention may be implemented.

[0025] Figure 2 FIG. is a schematic block diagram of a device for optical communication according to an embodiment of the present invention.

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

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

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

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

[0030] Figure 6 FIG. is a schematic diagram of the process of calibrating the optical axis of a device for optical communication by a control unit of the device according to an embodiment of the present invention.

[0031] Figure 7 FIG. is a schematic diagram of the process of calibrating the optical axis of a device for optical communication by a control unit of the device according to another embodiment of the present invention.

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

[0033] Figure 9 The figure shows a schematic diagram of the process of calibrating the first optical axis during the process of calibrating the optical axis according to an embodiment of the present invention.

[0034] In each of the drawings, the same or corresponding reference numerals denote the same or corresponding parts. Detailed implementation manners

[0035] 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 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 so that the present invention will be more thorough and complete, and can 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 "at least partially based 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 deficiencies of traditional devices for optical communication are: the time for calibrating the optical axis of the device is relatively long, and the calibration accuracy is relatively low.

[0038] As described above, traditionally, in order to calibrate the optical axis of a device for optical communication, it is necessary to repeatedly detect (for example, detect by a photodetector (APD)) the intensity of the signal light received by the device and correspondingly adjust the angles of the relevant optical components of the device, resulting in a relatively long calibration process and a relatively low calibration accuracy. In addition, this calibration method is only applicable when the device has scanned another device with which it will perform 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 spaceborne device installed on a satellite and manual calibration of the optical axis is impossible.

[0039] In addition, for spaceborne devices, during the satellite launch process, the devices will undergo a large degree of jolting and stress, resulting in a large deviation of the optical axis of the devices relative to the preset direction. This will lead to a very long in-orbit calibration process for the devices and very low accuracy. In addition, the wavelength of the calibration light emitted by the transmitting unit of the device is usually close to the wavelength of the signal light received by the receiving unit of the device from another device, and the transmitting optical axis for the transmitting unit to emit the calibration light is coaxial with the receiving optical axis for the receiving unit to receive the signal light. This will also result in a low transceiver isolation degree for the device.

[0040] To at least partially solve one or more of the above problems and other potential problems, example embodiments of the present invention propose a device for optical communication. In this device for optical communication, the optical axis of the device for optical communication is calibrated based on the positions of the spots respectively formed by the first calibration light, the second calibration light, and the second signal light detected by the fine 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] Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Figure 1 The figure shows a schematic diagram of an example environment in which a device for optical communication according to an embodiment of the present invention can be implemented. Figure 1 The shown example environment may represent an optical communication environment, which shows a scenario where a device 114 for optical communication provided on a satellite 112 performs optical communication with any one of corresponding devices 122, 124, 126... located on the ground. During the launch or operation of the satellite 112, the device 114 provided on the satellite 112 may experience a large degree of jolting and stress, resulting in a large deviation of the optical axis of the device 114 relative to the preset direction. Therefore, before the device 114 transmits signal light to any one of the corresponding devices 122, 124, 126..., it is necessary to calibrate the optical axis of the device 114 to ensure the communication quality of optical communication.

[0042] The following will describe the device for optical communication according to an embodiment of the present invention by taking the device 114 as an example. However, it should be understood that the embodiments of the present invention can be applied to Figure 1 other optical communication environments and other devices for optical communication different from those shown, for example, a ground optical communication environment, or ground devices (such as, Figure 1 the corresponding devices 122, 124, 126... in

[0043] Figure 2 The figure shows a schematic block diagram of a device for optical communication according to an embodiment of the present invention. In some embodiments, Figure 2The device shown can be an on-satellite device installed on a satellite. For example, Figure 1 the device 114 installed on the satellite 112 shown. In some other embodiments, Figure 2 the device shown can be a device installed on the ground. Figure 2 The device shown includes a transmitting unit 210, a receiving unit 220, a transceiver unit 230, a fine 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 distance 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, this distance can be the distance between the centers of the first core and the second core. Thereby, the first calibration light can be prevented from being coupled into the first core, thus preventing crosstalk between the first signal light and the first calibration light.

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

[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. The second signal light comes from another device that performs optical communication with the device (for example, Figure 1 any one of the corresponding devices 122, 124, 126... etc. shown).

[0047] In some embodiments, the distance between the third core and the fourth core can be greater than the diameter of the third core and the diameter of the fourth core. For example, this distance can be the distance between the centers of the third core and the fourth core. Making this distance greater than the diameter of the third core and the fourth core can make the distance between the third core and the fourth core greater than the numerical apertures of the third core and the fourth core. Thereby, the second calibration light can be prevented from being coupled into the third core, thus 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 arrangement of the dual-core optical fiber, the second calibration light can be used to indicate whether its current propagation direction (i.e., the optical axis direction) relative to the second signal light is a predetermined relative angle, that is, to indicate the current optical axis direction of the 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 embodiments of the present invention can have a high transceiver isolation degree.

[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 spot formed by the first calibration light in the fine tracking unit 240, a second position of a second spot formed by the second calibration light in the fine tracking unit 240, and a third position of a third 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 the focal plane of the fine tracking lens group in the fine tracking unit 240 and are the positions of the centroids of the corresponding 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 by using the first dual-core optical fiber and the second dual-core optical fiber as described above, the first position, the second position, and the third position respectively formed by the first calibration light, the second calibration light, and the second signal light in the fine tracking unit 240 can be separated from each other, the control unit 250 can accurately calibrate the optical axis of the device using a simple algorithm, thereby improving the efficiency and accuracy of calibration.

[0053] For the above device according to the embodiments of the present invention, by calibrating the optical axis of the device for optical communication based on the positions of the spots respectively formed by the first calibration light, the second calibration light, and the second signal light detected by the fine tracking unit 240, 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 refers to Figure 3 the schematic optical path diagram of the device shown to further describe the embodiments according to the present invention. Figure 3 The schematic optical path diagram of the device for optical communication according to the embodiments of the present invention is illustrated. Figure 3is shown in the optical path diagram Figure 2 the transmitting unit 210, the receiving unit 220, the transceiver unit 230, and the fine 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 the calibration according to the embodiments of the present invention. In Figure 3 the solid lines between the optical elements represent the optical paths, and the dashed arrows between the solid lines represent the propagation directions of the light in the corresponding optical path portions.

[0055] As Figure 3 shown, the transmitting unit 210 may include a first dual-core optical fiber 211, a transmitting mirror group 212, and a first fast steering mirror 213. The first core of the first dual-core optical fiber 211 can transmit the first signal light S1, and the second core of the first dual-core optical fiber 211 can transmit the first calibration light CA1. The transmitting mirror group 212 can be optically coupled to the first dual-core optical fiber 211. The first fast steering mirror 213 can 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 fast steering mirror 213, and further includes a second fast steering mirror 232, a first reflector 233, an optical antenna 234, a corner cube 235, a second beam splitter 236, and a second reflector 237. In some embodiments, the transceiver unit 230 may further include a filter 238. In some embodiments, the filter 238 can be optically coupled in the optical path between the first beam splitter 231 and the second beam splitter 236, as Figure 3 shown. In other embodiments, the filter 238 can be optically coupled in the optical path between the first beam splitter 231 and the corner cube 235.

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

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

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

[0060] In Figure 3 the example of, the first signal light S1 can be sequentially transmitted to another device via the first core of the first dual-core optical fiber 211, the transmitting mirror group 212, the first fast steering mirror 213, the first beam splitter 231, the second fast steering mirror 232, the first reflector 233, and the optical antenna 234.

[0061] The first calibration light CA1 can be sequentially transmitted to the fine tracking unit 240 via the second core of the first dual-core optical fiber 211, the transmitting mirror group 212, the first fast steering mirror 213, the first beam splitter 231, the corner cube 235, the first beam splitter 231, (and the filter 238) the second beam splitter 236, and the second reflector 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 can be sequentially transmitted to the receiving unit 220 via the optical antenna 234, the first reflector 233, the second fast steering mirror 232, the first beam splitter 231, (and the filter 238) the second beam splitter 236, and is also 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 can be transmitted to the receiving unit 220 while being 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 to the fine tracking unit 240 from the fourth core in the second dual-core optical fiber 221 of the receiving unit 220 via the receiving mirror group 222, sequentially via the second beam splitter 236, (and the filter 238) the first beam splitter 231, the corner cube 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] In Figure 3In the example, the first dual-core optical fiber 211 can be located at the focal plane of the transmitting mirror group 212, the second dual-core optical fiber 221 can be located at the focal plane of the receiving mirror group 222, and the camera 241 can be located at the focal plane of the fine tracking mirror group 242. Thus, on the left sides of the transmitting mirror group 212, the receiving mirror group 222, and the fine tracking mirror group 242 are the collimated beams of the corresponding light, and on the right sides are the focused beams of the corresponding light. For the case where one side of the mirror group has two collimated beams and the other side has 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 the corresponding relationship shown in the following formulas (1) and (2).

[0065] θ x = d x / F (1)

[0066] θ y = d y / F (2)

[0067] In the above formulas (1) and (2), F represents the focal length of the mirror group, θ x and θ y respectively represent the relative angle of the above two collimated beams along the x-axis direction and the relative angle along the y-axis direction of the mirror group coordinate system. The mirror group coordinate system can be a coordinate system in a plane parallel to Figure 3 the schematic diagram. d x and d y respectively represent the relative distance of the above two collimated beams along the x-axis direction and the relative distance along the y-axis direction in the focal plane of the mirror group. The focal plane coordinate system can be a coordinate system in a plane perpendicular to Figure 3 the schematic diagram. The above relative angles and relative distances all have directions (i.e., they can be positive or negative).

[0068] The above formulas (1) and (2) can be applied to the process of calibrating the optical axis of the device according to the embodiments of the present invention. The following will refer to Figures 4A to 9 to describe an example of calibrating the optical axis of the device according to the embodiments of the present invention. Figure 4A and Figure 4B respectively illustrate schematic cross-sectional views of the first dual-core optical fiber 211 and the second dual-core optical fiber 221 according to the embodiments of the present invention. Figure 4A and Figure 4B The cross-sectional views shown are taken along a plane perpendicular to Figure 3 the schematic diagram.

[0069] As Figure 4A shown, the spacing between the first core C1 and the second core C2 of the first dual-core optical fiber 211 is d 发射 , and the spacing d 发射 can be obtained through (dx发射 , d y发射 ) to represent. d x发射 and d y发射 can respectively represent: in the focal plane of the transmitting mirror group on the right side of the transmitting mirror group 212, the relative distances of the first signal light S1 and the first calibration light CA1 in the x-axis direction and the y-axis direction of the focal plane coordinate system of the transmitting mirror group. Substituting d 发射 (d x发射 , d y发射 ) into the above formulas (1) and (2), it can be obtained that: on the left side of the transmitting mirror group 212, the relative angles of the first signal light S1 and the first calibration light CA1 in the x-axis direction and the y-axis direction of the transmitting mirror group coordinate system are respectively θ 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 mirror group 212.

[0070] As Figure 4B shown, the distance between the third core C3 and the fourth core C4 of the second dual-core optical fiber 221 is d 接收 , and the distance d 接收 can be represented by (d x接收 , d y接收 ). d x接收 and d y接收 can respectively represent: in the focal plane of the receiving mirror group on the right side of the receiving mirror group 222, the relative distances of the desired second signal light S2 and the second calibration light CA2 in the x-axis direction and the y-axis direction of the focal plane coordinate system of the receiving mirror group. Substituting d 接收 (d x接收 , d y接收 ) into the above formulas (1) and (2), it can be obtained that: on the left side of the receiving mirror group 222, the relative angles of the desired second signal light S2 and the second calibration light CA2 in the x-axis direction and the y-axis direction of the receiving mirror group coordinate system are respectively θ 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 mirror group 222.

[0071] The above θ x发射 , θ y发射 , θ x接收 and θ y接收Insensitive to the jolts and stresses experienced by the device, and thus 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 calibration of the optical axis by the control unit 250 may be such that: in the transceiver unit 230, the first optical axis overlaps with the second optical axis. For example, this calibration causes the first optical axis and the second optical axis to overlap in the optical path between the second fast steering mirror 232 and the receiving mirror group 222 shown in Figure 3 the optical path between the second fast steering mirror 232 and the receiving mirror group 222 shown in

[0072] 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 spots formed by them in the fine 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 The figure shows a schematic diagram of the positions of the spots in the fine tracking unit 240 according to an embodiment of the present invention. As Figure 5 shown, the first calibration light CA1 is incident on the first position P1 (p x1 , p y1 ) in the camera 241 of the fine tracking unit 240, the second calibration light CA2 is incident on the second position P2 (p x2 , p y2 ) in the camera 241 of the fine tracking unit 240, and the second signal light S2 is incident on the third position P3 (p x3 , p y3 ) in the camera 241 of the fine tracking unit 240. 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 fine tracking mirror group. It should be understood that the above coordinate systems related to positions may be the same or different and can be converted to each other, and the above coordinate systems related to relative angles may be the same or different and can be converted to each other.

[0073] Figure 6 The figure shows a schematic diagram of the process of calibrating the optical axis of the device by the control unit 250 of the device for optical communication 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 the calibration performed during a non-optical communication phase when the device is not performing optical communication. In this case, there is no second signal light S2, so there is no third position of the second signal light S2 in the fine tracking unit 240. The control unit 250 can calibrate the optical axis of the device by using the first calibration light CA1 at the first position P1 (p x1 , p y1 ) in the fine tracking unit 240, and the second calibration light CA2 at the second position P2 (p x2 , p y2 ) as follows.

[0074] At block 602, the first relative distance between the first position P1 (p x1 , p y1 ) and the second position P2 (p x2 , p y2 ) can be determined. For example, the first relative distance can be expressed as △d1(d 1x = p x1 - p x2 , d 1y = p y1 - p y2 ).

[0075] At block 604, based on the first relative distance △d1 and the focal length F 精跟 of the fine tracking lens group in the fine tracking unit, the first relative angle between the first calibration light and the second calibration light is obtained. For example, using the above equations (1) and (2), the first relative angle θ1(θ 1x = d 1x / F 精跟 , θ 1y = d1 / F 精跟 ) can be obtained. The first relative angle can represent the actual relative angle between the first calibration light CA1 and the second calibration light CA2.

[0076] At block 606, the first relative angle can be compared with the first predetermined relative angle to obtain a first comparison result. In some embodiments, the first predetermined relative angle can be determined based on the following: the spacing d 发射 between the first core C1 and the second core C2, the spacing d 接收 between the third core C3 and the fourth core C4, the focal length F 发射 of the transmitting lens group 212 in the transmitting unit 210, and the focal length F 接收 of the receiving lens group 222 in the receiving unit 220. For example, the first predetermined relative angle can be based on the above θ x发射 , θ y发射 , θx接收 and θ y接收 to determine. The first predetermined relative angle may represent the expected relative angle between the first calibration light CA1 and the second calibration light CA2.

[0077] At block 608, based on the first comparison result, the tilt angle of at least one fast steering mirror in the device may be adjusted 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 may be completed by adjusting the first relative angle obtained at block 604 to the first predetermined relative angle in block 606.

[0078] The above describes the "non-real-time" calibration of the device. In the case of "real-time" calibration of the device, the first optical axis and the second optical axis of the device may also be calibrated based on the relationships shown in the above equations (1) and (2). "Real-time" calibration may refer to the calibration performed during the optical communication phase of the device for optical communication, for example, during the phase after the device scans another device with which it communicates.

[0079] Figure 7 FIG. illustrates a schematic diagram of a process for calibrating the optical axis of a device by a control unit 250 of a device for optical communication according to another embodiment of the present invention. Figure 7 The example corresponds to the above "real-time" calibration case. In this case, the control unit 250 may calibrate the optical axis of the device as follows by using the first position P1 (p x1 , p y1 ) of the first calibration light CA1 in the fine tracking unit 240, the second position P2 (p x2 , p y2 ) of the second calibration light CA2 in the fine tracking unit 240, and the third position P3 (p x3 , p y3 ) of the second signal light S2 in the fine tracking unit 240.

[0080] At block 702, the second relative distance between the second position P2 (p x2 , p y2 ) and the third position P3 (p x3 , p y3 ) may be determined. For example, the second relative distance may be expressed as Δd2 (d 2x = p x2 - p x3 , d 2y = p y2 - p y3 ).

[0081] At block 704, the second optical axis can be calibrated based on the second relative distance. In some embodiments, the second optical axis can be calibrated by obtaining the actual relative angle between the second signal light and the second calibration light based on the above equations (1) and (2) (which will be further described in the examples below).

[0082] At block 706, the third relative distance between the first position and the third position after calibrating the second optical axis can be determined. Here, since the second optical axis is calibrated at block 704, the transmission direction of the second signal light may change after calibration. In addition, since the direction of the second optical axis is adjusted by adjusting Figure 3 the tilt angle of the second fast steering mirror 232 in Figure 5 , and adjusting the tilt angle of the second fast steering mirror 232 will simultaneously change the direction of the first optical axis, after calibrating the second optical axis, the first position and the third position may change relative to x1 the positions shown. However, for ease of explanation, the current first position is still represented by P1(p y1 ), and the current third position is represented by P3(p x3 , p y3 ) to illustrate the third relative distance. For example, the third relative distance obtained as above can be expressed as Δd3(d 3x = p x1 - p x3 , d 3y = p y1 - p y3 ).

[0083] At block 708, the first optical axis can be calibrated based on the third relative distance. In some embodiments, the first optical axis can be calibrated by obtaining the actual relative angle between the first calibration light and the second signal light based on the above equations (1) and (2) (which will be further described in the examples below).

[0084] Figure 8 FIG. illustrates a schematic diagram of the process of calibrating the second optical axis during the process of calibrating the optical axis according to an embodiment of the present invention. Figure 8 The process shown corresponds to Figure 7 block 704 in Figure 8 . As shown in

[0085] , the control unit 250 can calibrate the second optical axis as follows. 2x , d 2y ), and the focal length F of the fine tracking mirror group in the fine tracking unit 精跟, to obtain a 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 ) can be obtained by using the above formulas (1) and (2). The second relative angle can represent the actual relative angle between the second calibration light CA2 and the second signal light S2.

[0086] At block 804, the second relative angle can be compared with a second predetermined relative angle to obtain a second comparison result. In some embodiments, the second predetermined relative angle can be determined based on the following: the spacing d 接收 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

[0087] of the receiving lens group 222 in the receiving unit 220. The second predetermined relative angle can represent the expected relative angle between the second calibration light CA2 and the second signal light S2. x接收 ,θ y接收 ). Thus, the second optical axis can be calibrated quickly and accurately.

[0088] 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 the tilt angle (e.g., the pitch angle) of the first fast steering mirror 213 in Figure 3 . Adjusting the tilt angle of the first fast steering mirror 213 only changes the direction of the first optical axis and does not change the direction of the second optical axis. Therefore, in the above embodiments, the second optical axis is calibrated first, and then the first optical axis is calibrated. It should be understood that when the actual optical path structure is different from that shown in Figure 3 , the first optical axis can also be calibrated first, and then the second optical axis can be calibrated, or both can be calibrated simultaneously.

[0089] Figure 9 illustrates a schematic diagram of the process of calibrating the first optical axis during the process of calibrating the optical axis according to an embodiment of the present invention. Figure 9 The process shown in Figure 7 corresponds to block 708 in Figure 9 . As shown in

[0090] At block 902, based on the 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 , the third relative angle between the first calibration light and the second signal light can be obtained. For example, using the above equations (1) and (2), the third relative angle θ3(θ 3x = d 3x / F 精跟 , θ 2y = d 3y / F 精跟 ) can be obtained. The third relative angle can represent the actual relative angle between the first calibration light CA1 and the second signal light S2.

[0091] At block 904, the third relative angle can be compared with a third predetermined relative angle to obtain a third comparison result. In some embodiments, the third predetermined relative angle can be determined based on the following: the spacing d 发射 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.

[0092] In this embodiment, since it is desired to calibrate 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 to overlap 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. Therefore, the above third comparison result can be used to calibrate the first optical axis.

[0093] At block 906, based on the third comparison result, the tilt angle of the fast steering mirror (e.g., the first fast steering mirror 213) in the transmitting unit 210 can be adjusted to adjust the third relative angle to the third predetermined relative angle (e.g., 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.

[0094] It should be understood that the optical path diagrams, relative positions, and relative angles shown in the above embodiments are merely examples, and different optical path diagrams, relative positions, and relative angles from the above can be set as needed.

[0095] The various processes and treatments described above, such as methods, may be executed at a computing device. The computing device includes, for example: at least one processor (at least one graphics processor and at least one central processor); and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the 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 onto the 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 executed.

[0096] 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 thereon computer-readable program instructions for performing various aspects of the present invention. The computer-readable storage medium may be a tangible device that can retain 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 of the foregoing.

[0097] The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or an external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and the combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0098] These computer-readable program instructions may be provided to a central processing unit of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine such that the instructions, when executed by the central processing unit of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions may also be stored in a computer-readable storage medium that causes a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer-readable medium storing the instructions comprises a manufacture including instructions for implementing various aspects of the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0099] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a segment of code, or a portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two consecutive blocks may in fact be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or acts, or by a combination of dedicated hardware and computer instructions.

[0100] It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps recited in this application may be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this application can be achieved, and no limitations are imposed herein.

[0101] The above specific embodiments do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can 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 The control unit is configured to calibrate the optical axis of the device based on the first position and the second position, or based on 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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