Optical antenna, control method thereof and communication terminal

Abstract

The invention relates to the technical field of space laser communication, and discloses an optical antenna, a control method thereof and a communication terminal, and the optical antenna comprises a signal receiving and transmitting lens group, a dispersion assembly and a butt joint light path assembly. The signal transmitting-receiving lens group is used for transmitting a signal light beam to the butt joint light path assembly through a light path and receiving the signal light beam from the butt joint light path assembly; the dispersion assembly is located on the light path and used for dispersing the signal light beams passing through the dispersion assembly, the signal light beams emitted by the signal receiving and transmitting mirror set and the received signal light beams have different wavelengths, different angle shifts can be generated under the dispersion effect of the dispersion assembly, and therefore the signal light beams are transmitted to the signal receiving and transmitting mirror set. Under the condition that a signal light beam emitted by the signal transceiving mirror group and a received signal light beam share the same light path, a required transceiving optical axis included angle is formed between the optical axis of the signal light beam emitted by the signal transceiving mirror group and the optical axis of the received signal light beam, so that the size of the optical antenna is reduced, the coupling efficiency during signal light beam transceiving is improved, and the signal quality is improved. And meanwhile, the change of a receiving and transmitting optical axis caused by non-common optical path of signal receiving and transmitting under the influence of an external environment is avoided, and the robustness of the system and the stability of link establishment are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of space laser communication, and particularly relates to an optical antenna, a control method thereof, and a communication terminal. Background Art

[0002] The optical parts of the transceiver of a traditional optical antenna generally include a beacon light emission optical path, a fine tracking optical path, a signal light receiving optical path, a signal light emission optical path, and a telescope. Some optical antennas do not have an independent beacon light emission optical path. Among them, the signal light transceiver optical path serves as an information carrier, and its link stability is crucial for satellite communication.

[0003] When the satellite is establishing a communication link, the distance between the transceiver terminals is far and there is relative motion. At the same time, due to the finite speed of light, there will be a certain relative position change between the transceiver terminals during the propagation of the light beam. To ensure the stable and efficient communication link, it is necessary to perform lead aiming, and there needs to be a certain lead angle between the emitted light beam and the received light beam (obtained by calculating the positions and speeds of the two terminals).

[0004] As Figure 1 shown, the current method for realizing the lead angle mainly relies on the transceiver separation element 03 to separate the signal light receiving optical path 011 and the signal light emission optical path 021. Among them, the signal light receiving mirror group 01 receives the signal light beam from other optical path structures 04 through the signal light receiving optical path 011, and the signal light emission mirror group 02 emits the signal light beam to other optical path structures 04 through the signal light emission optical path 012. The lead fast steering mirror 012 is used to reflect the light beam of the signal light receiving optical path 011, and the lead fast steering mirror 022 is used to reflect the light beam of the signal light receiving optical path 021. The lead aiming angle is obtained according to the calculation results of the ephemeris and the relative motion of the satellite, and the lead fast steering mirror 012 and the lead fast steering mirror 022 are relied on to swing to generate a small angular deviation between the transceiver light beams, that is, the lead aiming angle.

[0005] Relying on the lead fast steering mirror 012 and the lead fast steering mirror 022 to simulate the lead angle requires separating the signal light emission mirror group 02 and the signal light receiving mirror group 01 by means of dichroic, polarization beam splitting, and beam splitting plates, etc., which leads to a series of problems such as increased volume, reduced efficiency, and reduced available communication bands. At the same time, the signal light receiving optical path 011 and the signal light emission optical path 021 may be affected by different inter-satellite heat fluxes. In addition to different degrees of thermal expansion of the structure, the angle sensors of the lead fast steering mirror 012 and the lead fast steering mirror 022 may also have different degrees of temperature drift, thus resulting in an irreparable angular deviation amount, causing link degradation and reduced efficiency. Summary of the Invention

[0006] The present invention discloses an optical antenna, a control method thereof, and a communication terminal, which are used to reduce the volume of the optical antenna, alleviate link degradation, and improve the signal beam transceiver efficiency.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, an optical antenna is provided. The optical antenna includes: a signal transceiver mirror group, a dispersion component, and a docking optical path component; the signal transceiver mirror group is used to emit a signal beam to the docking optical path component through an optical path and receive the signal beam from the docking optical path component; the dispersion component is located on the optical path and is used to disperse the signal beam passing through the dispersion component. The signal beam emitted by the signal transceiver mirror group and the received signal beam have different wavelengths respectively. Under the action of the dispersion effect of the dispersion component, different angular offsets will be generated. Thus, an emission-reception optical axis angle is formed between the optical axis of the signal beam emitted by the signal transceiver mirror group and the optical axis of the received signal beam. Above, an advance angle is formed in the case where the signal beam emitted by the signal transceiver mirror group and the received signal beam share the same optical path, enabling full common optical path for inter-satellite transceiver. At the same time, the influence of the external heat flux in the inter-satellite environment on the emission-reception optical paths is completely the same, avoiding the situation of non-coaxiality due to different thermal effects on the emission-reception optical axes. In addition, by only adding a dispersion component, two sets of advance fast steering mirrors and one set of transceiver separation elements are reduced, and the signal light emission mirror group and the signal light reception mirror group are reduced to a signal transceiver mirror group, reducing the volume of the optical antenna and improving the coupling efficiency during signal beam transceiver. And only a certain isolation of the wavelengths of the emitted signal beam and the received signal beam is required, with no restrictions on wavelength and polarization. Therefore, the available waveband can be increased.

[0009] Optionally, the dispersion component includes at least one prism group, and each prism group includes a first prism located on the optical path.

[0010] Optionally, the dispersion component includes an even number of prism groups; in every two adjacent prism groups, at least one prism group is provided with a deflection driving component, and the deflection driving component is used to drive the corresponding prism group to rotate around the optical axis.

[0011] Optionally, each prism group further includes a second prism located on the optical path, and the apex angle direction of the second prism is opposite to the apex angle direction of the first prism.

[0012] Optionally, in each prism group, the first prism and the second prism are fixed and spliced into a square prism pair.

[0013] Optionally, the absolute value of the difference between the refractive index of the second prism and the refractive index of the first prism is less than or equal to 0.5.

[0014] Optionally, the refractive index of the first prism is less than that of the second prism, and the apex angle of the first prism is greater than that of the second prism.

[0015] Optionally, the dispersion ability of the second prism is higher than that of the first prism.

[0016] Optionally, the number of the prism groups is two.

[0017] Optionally, the dispersion component includes a grating dispersion element, a plasma dispersion element or an optical fiber dispersion element located on the optical path.

[0018] In a second aspect, there is provided a control method for an optical antenna according to any one of the technical solutions from the third to the ninth above, the control method including:

[0019] Calculating a target emission and reception optical axis angle based on the relative position between the optical antenna and the opposite antenna, the speed of the optical antenna, and the speed of the opposite antenna;

[0020] Controlling, according to the target emission and reception optical axis angle, the deflection driving component to drive the corresponding prism group to rotate around the optical axis, so that every two adjacent prism groups cooperate to adjust the emission and reception optical axis angle to the target emission and reception optical axis angle.

[0021] The advantages of the control method over the prior art are the same as those of the above optical antenna, and will not be described herein again.

[0022] In a third aspect, there is provided a communication terminal, which includes the optical antenna according to any one of the above technical solutions.

[0023] The advantages of the communication terminal over the prior art are the same as those of the above optical antenna, and will not be described herein again. Description of the Drawings

[0024] Figure 1 It is a signal beam transmission and reception schematic diagram of an optical antenna in the prior art;

[0025] Figure 2 It is a signal beam transmission and reception schematic diagram of the optical antenna provided by an embodiment of the present application;

[0026] Figure 3 It is Figure 2 a schematic diagram when the dispersion component 20 in the optical antenna shown is at maximum dispersion;

[0027] Figure 4 It is Figure 2 a schematic diagram when the dispersion component 20 in the optical antenna shown is at minimum dispersion;

[0028] Figure 5 indicate Figure 3 the corresponding dot array diagram;

[0029] Figure 6 indicate Figure 4 the corresponding dot array diagram. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention. It should be noted that the specific values given in the following embodiments are only for illustrative purposes to illustrate the technical principle, and the values can be adjusted accordingly.

[0031] Referring to Figure 2 , the optical antenna provided by the embodiments of the present application includes: a signal transceiver mirror group 10, a dispersion component 20, and a docking optical path component 30; the signal transceiver mirror group 10 is used to emit a signal beam to the docking optical path component 30 through an optical path and receive the signal beam from the docking optical path component 30; the docking optical path component 30 refers to the set of intermediate optical components for optical communication between the signal transceiver mirror group 10 and the dispersion component 20 and an external communication device, and may include a beacon light emission optical path, a fine tracking optical path, a telescope, etc.; the dispersion component 20 is located on the above optical path and is used to disperse the signal beam passing through the dispersion component 20. The signal beam emitted by the signal transceiver mirror group 10 and the received signal beam have different wavelengths respectively. Under the action of the dispersion effect of the dispersion component 20, different angular offsets will be generated. Thus, a required emission and reception optical axis angle (specifically, an advanced aiming angle) is formed between the optical axis of the signal beam emitted by the signal transceiver mirror group 10 and the optical axis of the received signal beam. Above, the emission and reception optical axis angle is formed in the case where the signal beam emitted by the signal transceiver mirror group 10 and the received signal beam share the same optical path. At the same time, the influence of the external heat flux in the inter-satellite environment on the emission and reception optical paths is exactly the same, avoiding the situation that the emission and reception optical axes are misaligned due to different thermal influences. In addition, in the case of only adding the dispersion component 20, two groups of advanced fast steering mirrors and one group of transmit-receive separation elements are reduced, and the signal light emission mirror group and the signal light reception mirror group are reduced to the signal transceiver mirror group 10, reducing the volume of the optical antenna and improving the coupling efficiency during signal beam transmission and reception. And only a certain isolation between the wavelengths of the emitted signal beam and the received signal beam is required, and there are no restrictions on the wavelength and polarization. Therefore, the available wavelength band can be increased. At the same time, the change of the emission and reception optical axes caused by the non-common optical path of signal transmission and reception under the influence of the external environment is avoided, greatly improving the system robustness and link establishment stability.

[0032] In a specific embodiment, the dispersion component 20 includes at least one prism group. Each prism group includes a first prism a located on the above optical path. The first prism a can be a triangular prism. The first prism a has a good dispersion effect on light rays. After dispersion, light beams of different wavelengths are separated, so that light beams of different wavelengths form the above-mentioned emission and reception optical axis angle. The prism group has a simple design, is easy to manufacture, and has a low cost. By changing the prism material, the dispersion ability of the prism in the prism group (such as the first prism a) can be adjusted.

[0033] In a specific embodiment, the dispersion component 20 includes an even number of prism groups; in every two adjacent prism groups, at least one prism group is provided with a deflection driving component, and the deflection driving component is used to drive the corresponding prism group to rotate around the optical axis. As Figure 3 shown, the apex angles of the first prism a in the first prism group L1 and the first prism a in the second prism group L2 are in the same direction, both facing downwards, which means that when dispersing the light beam, both first prisms a give dispersion perpendicular to the optical axis upward (+y direction). At this time, the maximum degree of dispersion is achieved; among them, the second prism group L2 is provided with a deflection driving component, such as a deflection motor. When it is necessary to adjust the dispersion ability of the dispersion component 20, the deflection driving component can be controlled to rotate the prism group L1 or the prism group L2 around the optical axis; as Figure 4 shown, the apex angles of the first prism a in the first prism group L1 and the first prism a in the second prism group L2 are in opposite directions. The prism group L2 is driven by the deflection driving component to rotate 180° around the optical axis. The apex angle of the first prism a in the prism group L2 faces upward. The first prism a in the prism group L1 gives dispersion perpendicular to the optical axis upward (+y direction), and the first prism a in the prism group L2 gives dispersion perpendicular to the optical axis downward (-y direction). At this time, the front and rear first prisms a achieve dispersion complementarity, and the comprehensive dispersion effect is the smallest. If the dispersion ability of the first prism a in the prism group L1 is the same as that of the first prism a in the prism group L2, the comprehensive dispersion ability is complementary to zero.

[0034] In a specific embodiment, each prism group further includes a second prism b located on the optical path. The apex angle direction of the second prism b is opposite to that of the first prism a; the materials of the first prism a and the second prism b can both be glass. Similar to the first prism a, as Figure 3 shown, both second prisms b give dispersion perpendicular to the optical axis downward (-y direction). At this time, the maximum degree of dispersion is achieved; as Figure 4, the second prism b in the prism group L1 gives dispersion perpendicular to the optical axis downward (-y direction), and the second prism b in the prism group L2 gives dispersion perpendicular to the optical axis upward (+y direction). At this time, the front and rear second prisms b achieve complementary dispersion, and the combined dispersion effect is the smallest. If the dispersion capabilities of the second prism b in the prism group L1 and the second prism b in the prism group L2 are the same, the combined dispersion capability is complementary to zero. The dispersion direction of the second prism b in the same prism group can be corrected by using the first prism a, or the dispersion direction of the first prism a in the same prism group can be corrected by using the second prism b to avoid excessive deflection of the optical axis. For this purpose, the first prism a and the second prism b can have a large difference in dispersion capability. For example, the dispersion capability of the second prism b is higher than that of the first prism a, and can be significantly higher than that of the first prism a. In this way, the first prism a can play a certain reverse correction role in the dispersion effect of the second prism b to avoid excessive deflection of the optical axis.

[0035] For example Figure 3 and Figure 4 , the number of prism groups can specifically be 2, namely the prism group L1 and the prism group L2. Only by controlling the rotation of the prism group L1 or the prism group L2 around the optical axis, a suitable dispersion capability can be selected between the maximum dispersion and the minimum dispersion. However, in order to facilitate the adjustment between the minimum dispersion degree (such as zero) and the maximum dispersion degree, an even number of prism groups can be set. The number of prism groups can also be 4, 6, 8, etc. Taking the prism group L1 and the prism group L2 as a fixed combination, from the object surface to the image surface, any number of the above fixed combinations are arranged at intervals in turn, and the minimum dispersion degree can reach zero, while the maximum dispersion degree is the sum of the maximum dispersion degrees of the above fixed combinations.

[0036] In a specific embodiment, in each prism group, the first prism a and the second prism b can both be triangular prisms, and are fixed and spliced into a square prism pair. By using a deflection driving component to rotate the square prism pair, the first prism a and the second prism b in the square prism pair can be rotated simultaneously, reducing the number of deflection driving components used. At the same time, the movement consistency of the first prism a and the second prism b can be improved, avoiding misalignment during their movement and preventing the first prism a from playing the pre-designed optical axis correction role.

[0037] In a specific embodiment, the absolute value of the difference between the refractive index of the second prism b and the refractive index of the first prism a is less than or equal to 0.5, such as 0.5, 0.4, 0.3, 0.2, 0.1, and 0, etc., so that the first prism a can basically correct the deflection of the optical axis of the second prism b. If the absolute value of the difference in refractive indices is too large, the deflection of the optical axis caused by the second prism b is too large, and it is necessary to make up for the deflection of the optical axis caused by the difference in refractive indices by making the first prism a and the second prism b have a large vertex angle difference. If the vertex angle difference is too large, the main optical path axis will have an obvious radial offset, or cause a certain degree of beam expansion of the main beam.

[0038] In a specific embodiment, the refractive index of the first prism a is less than the refractive index of the second prism b. For example, the refractive index of the first prism a for a beam with a wavelength of 1550 nm is 1.5781, and the refractive index of the second prism b for a beam with a wavelength of 1550 nm is 1.5885; and the vertex angle of the first prism a is greater than the vertex angle of the second prism b. For example, the vertex angle of the first prism a is 25°, and the vertex angle of the second prism b is 24.53°. The slight difference in the vertex angles of the first prism a and the second prism b is used to make up for the deflection of the optical axis caused by the difference in refractive indices, so that while the optical axis of the received and transmitted signal beams has a slight offset, the main beam can maintain its original trajectory.

[0039] The dispersion component 20 plays a role in dispersion and is not limited to the form of the first prism a and the second prism b. For example, in a specific embodiment, the dispersion component 20 includes a grating dispersion element, a plasma dispersion element, or an optical fiber dispersion element located on the optical path. The grating dispersion element realizes dispersion based on the diffraction principle. When a beam passes through the grating dispersion element, light rays of different wavelengths generate different diffraction angles, and the output end of the grating dispersion element can emit signal beams of different wavelengths at different angles. An included angle between the received and transmitted optical axes of the signal beams received by the signal transceiver mirror group 10 can be formed, and the dispersion ability can be controlled by controlling the shape of the grating in the grating dispersion element. When a beam passes through the plasma dispersion element, the propagation speeds of beams of different wavelengths (or different frequencies) are different, and thus, a dispersion effect is generated, so that an included angle between the received and transmitted optical axes of the signal beams received by the signal transceiver mirror group 10 can be formed, and the dispersion ability can be controlled by controlling parameters such as the plasma density and temperature of the plasma dispersion element. When a beam passes through the optical fiber dispersion element, the transmission speeds of signal beams with different frequency components and different modes are different, and thus, a dispersion effect is generated, so that an included angle between the received and transmitted optical axes of the signal beams received by the signal transceiver mirror group 10 can be formed, and the dispersion ability can be controlled by controlling the optical fiber material, etc. Specifically, one or several of these dispersion elements can be arranged on the optical path, or they can be mixed with the first prism a and the second prism b in the previous text to superimpose the dispersion effect and expand the adjustment range of the included angle between the received and transmitted optical axes.

[0040] The effects of the above dispersion component 20 will be described below with specific parameters.

[0041] Taking the wavelength of the signal light beam emitted by the signal transceiver lens group 10 as 1535 nm and the wavelength of the received signal light beam as 1565 nm as an example, both deviate from the wavelength of the main light beam of 1550 nm by 15 nm.

[0042] Reference Figure 5 When the dispersion component 20 is in the state of maximum dispersion as shown in Figure 3 , the signal light beam with a wavelength of 1535 nm and the signal light beam with a wavelength of 1565 nm deviate from the main light beam with a wavelength of 1550 nm by 76.168 μrad, that is, the maximum included angle between the transmitting and receiving optical axes that can be simulated can reach 76.168 μrad.

[0043] Reference Figure 6 When the dispersion component 20 is in the state of minimum dispersion as shown in Figure 4 , the prism group L1 and the prism group L2 compensate for each other in terms of dispersion, and the dispersion is zero, which is equivalent to not performing any transformation on the input light beam. The main ray with a wavelength of 1550 nm, the signal light beam with a wavelength of 1535 nm, and the signal light beam with a wavelength of 1565 nm are basically coincident.

[0044] Among them, the light beams with the above wavelengths are only exemplary data.

[0045] The included angle between the received signal light beam and the emitted signal light beam provided by the dispersion component 20 can be represented by a vector. Assuming that the unit vector of the initial light beam is The nth dispersion element (such as the prism group L1) provides The radial dispersion vector of the transmitting and receiving optical axes, The modulus of which is related to the dispersion ability of the dispersion element, and its direction is determined by the dispersion orientation of the dispersion element. The direction vector after passing through n dispersion elements can be expressed as The included angle between the transmitting and receiving optical axes (specifically, it can be the leading aiming angle)

[0046] Assuming the initial situation is the maximum dispersion state as shown in Figure 3 , the unit vector of the signal light beam propagating along the optical axis is The radial dispersion vectors that each prism group (such as the prism group L1 and the prism group L2) can provide are respectively Ideally, calculated according to the actual refractive index data of the material, In the initial situation, the directions of the two are the same. The prism group L1 rotates around the optical axis by an angle of α(t), and the prism group L2 rotates around the optical axis by an angle of β(t). Then the dispersion amount of this dispersion component 20 can be expressed as:

[0047]

[0048] By rotating the prism group L1 and the prism group L2, this solution can provide a light emission and reception optical axis angle ranging from to rad for the signal light beam emitted, that is, a light emission and reception optical axis angle with any azimuth and size within this range. α(t) and β(t) are a set of functions related to the leading angle value at time t.

[0049] Based on the same inventive concept, an embodiment of the present application further provides a control method for the above optical antenna. The control method includes: calculating a target light emission and reception optical axis angle according to the relative position between the optical antenna and the opposite antenna, the speed of the optical antenna, and the speed of the opposite antenna; controlling the deflection drive assembly to drive the corresponding prism group to rotate around the optical axis according to the target light emission and reception optical axis angle, so that every two adjacent prism groups cooperate to adjust the light emission and reception optical axis angle to the target light emission and reception optical axis angle.

[0050] The beneficial effects of this control method can refer to the description of the relevant part of the optical antenna in the previous text.

[0051] Based on the same inventive concept, an embodiment of the present application further provides a communication terminal. The communication terminal includes the optical antenna provided in the above embodiment. The beneficial effects of the communication terminal can refer to the relevant effect description of the optical antenna in the previous text.

[0052] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. An optical antenna, characterized in that, Comprising: A signal transceiver lens group, a dispersion component, and a docking optical path component; The signal transceiver lens group is configured to emit a signal beam to the docking optical path component through an optical path and receive a signal beam from the docking optical path component; The dispersion component is located on the optical path and is configured to disperse the signal beam passing through the dispersion component, so as to form a light axis angle between the optical axis of the signal beam emitted by the signal transceiver lens group and the optical axis of the received signal beam; wherein, The signal beam emitted by the signal transceiver lens group and the received signal beam have different wavelengths respectively.

2. The optical antenna according to claim 1, characterized in that The dispersion component includes at least one prism group, and each prism group includes a first prism located on the optical path.

3. The optical antenna according to claim 2, wherein, The dispersion component includes an even number of the prism groups; In each adjacent two prism groups, at least one prism group is provided with a deflection driving component, and the deflection driving component is configured to drive the corresponding prism group to rotate around the optical axis.

4. The optical antenna according to claim 3, characterized in that, Each prism group further includes a second prism located on the optical path, and the apex angle direction of the second prism is opposite to the apex angle direction of the first prism.

5. The optical antenna according to claim 4, characterized in that, In each prism group, the first prism and the second prism are fixed and spliced into a square prism pair.

6. The optical antenna according to claim 4 or 5, characterized in that, The absolute value of the difference between the refractive index of the second prism and the refractive index of the first prism is less than or equal to 0.

5.

7. The optical antenna according to claim 6, wherein The refractive index of the first prism is less than the refractive index of the second prism, and the apex angle of the first prism is greater than the apex angle of the second prism.

8. The optical antenna according to claim 7, wherein The dispersion ability of the second prism is higher than the dispersion ability of the first prism.

9. The optical antenna according to claim 3, characterized in that, The number of the prism groups is 2.

10. The optical antenna according to claim 1, characterized in that, The dispersion component includes a grating dispersion element, a plasma dispersion element or an optical fiber dispersion element located on the optical path.

11. A control method for an optical antenna as described in any one of claims 3 to 9, characterized in that, Comprising: Calculating a target light axis angle based on the relative position between the optical antenna and the opposite antenna, the speed of the optical antenna, and the speed of the opposite antenna; According to the target light axis angle, controlling the deflection driving component to drive the corresponding prism group to rotate around the optical axis, so that each adjacent two prism groups cooperate to adjust the light axis angle to the target light axis angle.

12. A communication terminal, characterized in that, Comprising the optical antenna according to any one of claims 1 to 10.

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