Optical Phased Array

Abstract

An optical phased array includes: a beam splitter for splitting a light source signal into multiple paths; a plurality of phase shifters coupled to the multiple output ends of the beam splitter in a one-to-one correspondence, for respectively receiving the multiple optical signals after the beam splitting and performing phase shift processing; an antenna array including a plurality of antennas, the plurality of antennas coupled to the plurality of phase shifters in a one-to-one correspondence, for receiving the optical signals after the phase shift processing; wherein the optical path from each multiple output end of the beam splitter to the corresponding antenna input end is equal. The present invention can simultaneously meet the requirements of compact layout and consistent length of waveguides of each channel.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technology, and in particular to an optical phased array. Background Art

[0002] Optical phased array is a technology that realizes spatial steering of light beams. It is the core component of chip-level laser radar and can be applied to fields such as spatial ranging and scanning imaging. Compared with mechanical scanning technology, it has the advantages of small size, fast scanning speed, low cost and high precision. The one-dimensional array of optical phased array realizes two-dimensional scanning of light beams by controlling the optical phase of each channel and the wavelength of the incident light.

[0003] In existing optical phased arrays, there are multiple optical paths from the laser through the phase shifter to the antenna, and the optical path difference between the paths is often large. In addition, for large-scale optical phased arrays, the number of unit devices can reach hundreds to thousands. If the wiring method is unreasonable, the device may occupy too much area and the chip manufacturing cost may be too high.

[0004] There is an urgent need for an optical phased array that can simultaneously meet the requirements of compact layout and consistent waveguide length of each channel by setting a reasonable wiring method. Summary of the invention

[0005] The technical problem solved by the present invention is to provide an optical phased array which can simultaneously meet the requirements of compact layout and consistent length of waveguides in each channel.

[0006] To solve the above technical problems, an embodiment of the present invention provides an optical phased array, characterized in that it includes: a splitter, used to split a light source signal into multiple paths; a plurality of phase shifters, coupled one-to-one with the multi-path output ends of the splitter, used to respectively receive the multi-path light signals after splitting and perform phase shifting processing; an antenna array, including a plurality of antennas, the plurality of antennas are coupled one-to-one with the plurality of phase shifters, used to receive the light signals after phase shifting processing; wherein the optical path between each multi-path output end of the splitter to the corresponding antenna input end is equal.

[0007] Optionally, an extension direction of the phase shifter is different from an output direction of the multi-path output end of the optical splitter, and an extension direction of the phase shifter is different from an extension direction of a corresponding antenna.

[0008] Optionally, the splitter includes a main link splitter unit and a multi-layer splitting structure, each layer of the splitting structure includes multiple branch link splitter units; each layer of the splitting structure contains one or more 1×2 tree structures, and the optical path between each branch link splitter unit and the main link splitter unit in the same layer of the splitting structure is equal.

[0009] Optionally, the number of the phase shifters is an even number; the light paths output from the multi-path output end of the splitter are divided into two groups, and the two groups of light paths are arranged axially symmetrically; the phase shifters corresponding to the multi-path output end of the splitter are divided into two groups, and the two groups of phase shifters are arranged axially symmetrically.

[0010] Optionally, the symmetry axes of the two groups of optical paths are parallel to the symmetry axes of the two groups of phase shifters.

[0011] Optionally, the symmetry axes of the two groups of optical paths and the symmetry axes of the two groups of phase shifters are both lines connecting the input end of the optical splitter to the center points of the multiple access ends of the antenna array.

[0012] Optionally, the optical splitter and the antenna array are equally divided into two groups, and the optical splitter, the phase shifter corresponding to the multi-path output end of the optical splitter, the optical path output from the multi-path output end of the optical splitter, and the antenna array use the same symmetry axis.

[0013] Optionally, an extension direction of the phase shifter is perpendicular to an output direction of the multi-path output end of the optical splitter, and an extension direction of the phase shifter is perpendicular to an extension direction of an antenna corresponding to the phase shifter.

[0014] Optionally, the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle.

[0015] Optionally, the optical phased array further includes: a plurality of first optical waveguides, each first optical waveguide being connected to a multi-path output end of the optical splitter and a corresponding phase shifter; wherein the first optical waveguide has a bend, and the absolute values ​​of the bend angles between the first optical waveguides are equal.

[0016] Optionally, the optical phased array further includes: a plurality of second optical waveguides, each second optical waveguide being connected to the phase shifter and a corresponding antenna; wherein the second optical waveguide has a bend, and the absolute values ​​of the bend angles between the second optical waveguides are equal.

[0017] Optionally, the output direction of the multi-path output end of the optical splitter is the same as the extension direction of the corresponding antenna.

[0018] Optionally, the spacing between adjacent antennas in the antenna array is equal to the spacing between adjacent light output ends of the optical splitter.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0020] In the embodiment of the present invention, by setting the optical path lengths between each multi-channel output end of the optical phased array splitter and the corresponding antenna input end to be equal, compared with simply and directly laying out the phase shifter in the X direction (the direction from each multi-channel output end of the splitter to the corresponding antenna input end), the optical path lengths between each multi-channel output end of the splitter and the corresponding antenna input end can be kept equal, thereby simultaneously meeting the requirements of compact layout and consistent waveguide lengths of each channel. Furthermore, since when the optical path lengths of each optical path channel are equal, only one-dimensional calibration is required for the X direction (antenna extension direction, also called antenna direction) of the antenna array, and even if the incident wavelength is changed, there is no need to calibrate the Y direction (antenna arrangement direction, also called array direction) of the antenna array, thereby achieving the optimization of the optical phased array phase calibration time while reducing the length of the optical phased array in the X direction.

[0021] Furthermore, by setting the extension direction of the phase shifter to be different from the output direction of the multi-way output end of the splitter, and the extension direction of the phase shifter to be different from the extension direction of the corresponding antenna, the length of the optical phased array in the Y direction (perpendicular to the output direction of each multi-way output end of the splitter) can be reduced, thereby better meeting the user's specific requirements for the aspect ratio of the optical phased array.

[0022] Furthermore, each layer of the splitting structure includes one or more 1×2 tree structures, and the optical paths between each branch link splitter unit and the main link splitter unit in the same layer of the splitting structure are equal, so that the optical paths between each channel from the splitter input end to the splitter output end are consistent, so that the optical paths of each optical signal of the optical phased array are equal not only between the splitter output end and the antenna input end, but also before the splitter output end, thereby further achieving the effect of no optical path difference for each optical signal.

[0023] Furthermore, the extension direction of the phase shifter is perpendicular to the output direction of the multi-way output end of the beam splitter, and the extension direction of the phase shifter is perpendicular to the extension direction of the antenna corresponding to the phase shifter. When the beam splitter and the antenna are located in the X direction (the direction from each multi-way output end of the beam splitter to the corresponding antenna input end), the phase shifter is located in the Y direction, and the X direction is perpendicular to the Y direction, which can effectively reduce the length of the optical phased array in the Y direction.

[0024] Furthermore, the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle, so that the optical splitter, the phase shifter, and the antenna can be arranged in a Z shape, thereby reducing the length of the optical phased array in the Y direction while effectively reducing the length of the optical phased array in the X direction (the direction from each multi-path output end of the optical splitter to the corresponding antenna input end).

[0025] Furthermore, the optical paths output from the multi-channel output end of the optical splitter are divided into two groups, and the two groups of optical paths are arranged axially symmetrically; the phase shifters corresponding to the multi-channel output end of the optical splitter are divided into two groups, and the two groups of phase shifters are arranged axially symmetrically, which can achieve symmetrical distribution of the optical paths and reduce the length of the optical phased array in the X direction (the direction from each multi-channel output end of the optical splitter to the corresponding antenna input end). Furthermore, by providing a first optical waveguide connecting the multi-channel output end of the optical splitter and the corresponding phase shifter, the first optical waveguide has a bend, and the absolute values ​​of the bend angles between the first optical waveguides are equal, so that the optical paths can be kept parallel, which is conducive to better maintaining the equality of the optical path from each multi-channel output end to the corresponding antenna input end. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an optical phased array in the prior art;

[0027] Figure 2 is a schematic structural diagram of a first optical phased array in an embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a second optical phased array in an embodiment of the present invention;

[0029] Figure 4 is a schematic structural diagram of a third optical phased array in an embodiment of the present invention;

[0030] Figure 5 is a schematic structural diagram of a fourth optical phased array in an embodiment of the present invention;

[0031] Figure 6 It is a schematic diagram of two-dimensional scanning phase calibration in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In existing optical phased arrays, there are multiple optical paths from the laser through the phase shifter to the antenna, and the optical path difference between the paths is often large. In addition, for large-scale optical phased arrays, the number of unit devices can reach hundreds to thousands. If the wiring method is unreasonable, the device may occupy too much area and the chip manufacturing cost may be too high.

[0033] The inventor of the present invention has found through research that in the prior art, due to the large scale of silicon waveguide arrays, the phase error is also large, and phase calibration needs to be performed at each position of the two-dimensional scan. If each point in the two-dimensional array is calibrated in turn, it will take a lot of time. However, when the waveguide lengths of each channel meet the equal condition, only one-dimensional calibration is required for the array direction, and the antenna direction does not need to be calibrated when the incident wavelength is changed, so it is necessary to reduce the optical path difference between each optical path channel.

[0034] Reference Figure 1 , Figure 1 It is a structural schematic diagram of an optical phased array in the prior art.

[0035] The optical phased array may include a beam splitter 12 , a phase shifter array 13 including a plurality of phase shifters, and an antenna array 14 .

[0036] The optical splitter 12 may be used to split the light source signal of the light source 11 into multiple light signals.

[0037] The multiple phase shifters of the phase shifter array 13 can be coupled to the multi-path output ends of the optical splitter 12 in a one-to-one correspondence, so as to respectively receive the multi-path optical signals after the splitting and perform phase shift processing.

[0038] The antenna array 14 includes a plurality of antennas, which are coupled to the plurality of phase shifters in a one-to-one correspondence, and are used to receive the optical signal after phase shift processing and emit the light in the waveguide into space.

[0039] exist Figure 1 The optical phased array shown in the figure has the problem of unequal optical path lengths between the various multi-path output ends of the beam splitter 12 and the corresponding antenna input ends. For example, the optical path length through the phase shifters in the edge area (such as the top or bottom phase shifters) is longer, while the optical path length through the phase shifters in the center area (such as the two middle phase shifters) is shorter.

[0040] The inventors of the present invention have further discovered through research that when the density of the designed optical phased array is high, the crosstalk problem between waveguides needs to be considered; in addition, the layout drawing must meet the process requirements, and the spacing requirements of different devices are different. Therefore, it is difficult to design a silicon-based optical phased array that meets the requirements of high integration, low crosstalk, and equal length of waveguides in each channel. Specifically, since the beam splitter is usually small in size and the phase shifter is usually large in size, it is not easy to directly use Figure 1 In the one-dimensional connection method shown, the laser, the beam splitter, multiple phase shifters, and the antenna array are connected in series. The area occupied by the phase shifter part is too large, resulting in a shorter optical light path between the beam splitter and the phase shifter in the center area, and a longer optical light path between the beam splitter and the phase shifter in the edge area.

[0041] In the embodiment of the present invention, by setting the optical path lengths between each multi-channel output end of the optical phased array splitter and the corresponding antenna input end to be equal, compared with simply and directly laying out the phase shifter in the X direction (the direction from each multi-channel output end of the splitter to the corresponding antenna input end), the optical path lengths between each multi-channel output end of the splitter and the corresponding antenna input end can be kept equal, thereby simultaneously meeting the requirements of compact layout and consistent waveguide lengths of each channel. Furthermore, when the optical path lengths of each optical path channel are equal, only one-dimensional calibration is required for the X direction (antenna extension direction, also called array direction) of the antenna array, and even if the incident wavelength is changed, there is no need to calibrate the Y direction (antenna arrangement direction, also called antenna direction) of the antenna array, thereby achieving the optimization of the optical phased array phase calibration time while reducing the length of the optical phased array in the X direction.

[0042] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] Reference Figure 2 , Figure 2 It is a schematic diagram of the structure of the first optical phased array in an embodiment of the present invention.

[0044] The first optical phased array may include: a beam splitter 22 , a phase shifter array 23 including a plurality of phase shifters, and an antenna array 24 , and may also include a first optical waveguide 25 and a second optical waveguide 26 .

[0045] The optical splitter 22 may be used to split the light source signal of the light source 21 into multiple paths.

[0046] Specifically, the light source 21 may be a laser integrated in a silicon photonic chip, or may be an external light source. The light source 21 may be, for example, an adjustable narrow linewidth laser to provide a more accurate optical signal.

[0047] A plurality of phase shifters may be coupled to the multi-path output ends of the optical splitter 22 in a one-to-one correspondence, and are used to respectively receive the multi-path optical signals after the splitting and perform phase shift processing.

[0048] in, Figure 2 The multi-channel output end of the optical splitter 22 shown in the figure may be 8-channel output ends, which are represented by output ends T1 to T8 respectively.

[0049] The antenna array 24 may include multiple antennas, which are coupled to the multiple phase shifters in a one-to-one correspondence, and are used to receive the optical signal after phase shift processing. After receiving, the antenna array 24 can emit the light in the waveguide into space.

[0050] in, Figure 2The antenna array 24 shown may use the X direction to represent the antenna extension direction, also referred to as the antenna direction, and the Y direction to represent the antenna arrangement direction, also referred to as the array direction.

[0051] The optical paths from each multi-channel output terminal of the optical splitter 22 to the corresponding antenna input terminal are equal.

[0052] Furthermore, the splitter 22 may include a main link splitter unit and a multi-layer splitting structure, each layer of the splitting structure includes multiple branch link splitter units; each layer of the splitting structure contains one or more 1×2 tree structures, and the optical path between each branch link splitter unit and the main link splitter unit in the same layer of the splitting structure is equal.

[0053] like Figure 2 The illustrated beam splitter 22 may include three layers of beam splitting structures, and each layer of the beam splitting structure may perform beam splitting via a beam splitter unit.

[0054] Specifically, Figure 2 The first layer splitting structure of the splitter 22 shown can be a 1×2 tree structure, the first layer splitting structure includes 2 branch link splitter units, and then each branch link splitter unit is split to the second layer splitting structure via the 1×2 tree structure, and the second layer splitting structure includes 4 branch link splitter units, and then each branch link splitter unit is split to the third layer splitting structure via the 1×2 tree structure, and the third layer splitting structure is output through 8 branch links.

[0055] Among them, the optical path between the two branch link splitter units in the first layer of splitting structure and the main link splitter unit is equal, that is, the transmission length of the optical signal from the main link splitter unit to the two branch link splitter units in the first layer of splitting structure is consistent.

[0056] The optical path lengths between the 4 branch link splitter units of the second-layer splitting structure and the main link splitter unit are equal, that is, the transmission lengths of the optical signals from the main link splitter unit to the 4 branch link splitter units of the second-layer splitting structure are consistent; the optical path lengths between the 8 branch links of the third-layer splitting structure and the main link splitter unit are equal, that is, the transmission time lengths of the optical signals from the main link splitter unit to the 8 branch links of the third-layer splitting structure are consistent.

[0057] In an embodiment of the present invention, each layer of the splitting structure includes one or more 1×2 tree structures, and the optical paths between each branch link splitter unit and the main link splitter unit in the same layer of the splitting structure are equal, so that the optical paths between each channel from the splitter input end to the splitter output end are consistent, so that the optical paths of each optical signal of the optical phased array are equal not only between the splitter output end and the antenna input end, but also before the splitter output end, thereby further achieving the effect of no optical path difference for each optical signal.

[0058] In the embodiment of the present invention, by setting the optical path lengths between each multi-channel output end of the optical phased array spectrometer 21 and the corresponding antenna input end to be equal, compared with simply and directly laying out the phase shifter in the X direction (the direction from each multi-channel output end of the spectrometer to the corresponding antenna input end), the optical path lengths between each multi-channel output end of the spectrometer and the corresponding antenna input end can be kept equal, thereby simultaneously meeting the requirements of compact layout and consistent waveguide lengths of each channel. Furthermore, since when the optical path lengths of each optical path channel are equal, only one-dimensional calibration is required for the X direction (antenna extension direction, also called antenna direction) of the antenna array, and even if the incident wavelength is changed, there is no need to calibrate the Y direction (antenna arrangement direction, also called array direction) of the antenna array, thereby achieving the optimization of the optical phased array phase calibration time while reducing the length of the optical phased array in the X direction.

[0059] Furthermore, the extension direction of each phase shifter in the phase shifter array 23 is different from the output direction of the multi-path output end of the optical splitter, and the extension direction of the phase shifter is different from the extension direction of the corresponding antenna.

[0060] like Figure 2 The output direction of the multi-path output end of the spectrometer is shown to be in the X direction. It should be pointed out that as long as the extension direction of each phase shifter in the phase shifter array 23 is not in the X direction, for example, it is diagonal from the upper right to the lower left, vertical direction (Y direction), or diagonal from the upper left to the lower right, the length of the optical phased array in the Y direction can be reduced.

[0061] In the embodiment of the present invention, by setting the extension direction of the phase shifter to be different from the output direction of the multi-way output end of the splitter, and the extension direction of the phase shifter to be different from the extension direction of the corresponding antenna, the length of the optical phased array in the Y direction (perpendicular to the output direction of each multi-way output end of the splitter) can be reduced, thereby better meeting the user's specific requirements for the aspect ratio of the optical phased array.

[0062] Furthermore, the output direction of the multi-path output end of the optical splitter 22 may be the same as the extension direction of the corresponding antenna.

[0063] In the embodiment of the present invention, by setting the output direction of the multi-path output end of the optical splitter to be the same as the extension direction of the corresponding antenna, the requirements of compact layout and consistent length of waveguides of each channel can be better met at the same time.

[0064] Furthermore, the spacing between adjacent antennas in the antenna array 24 may be equal to the spacing between adjacent optical output ends of the optical splitter.

[0065] like Figure 2 The spacing between adjacent antennas in the antenna array 24 shown is d, and the spacing between adjacent light output ends of the optical splitter may also be d.

[0066] In the embodiment of the present invention, by setting the spacing between adjacent antennas in the antenna array 24 to be equal to the spacing between adjacent optical output ends of the optical splitter, the requirements of compact layout and consistent waveguide length of each channel can be better met at the same time.

[0067] In a first specific implementation of the embodiment of the present invention, Figure 2 As shown, the extending direction of the phase shifter is perpendicular to the output direction of the multi-path output end of the optical splitter 22, and the extending direction of the phase shifter is perpendicular to the extending direction of the antenna corresponding to the phase shifter.

[0068] Specifically, the extension direction of the phase shifter is perpendicular to the output direction of the multi-way output end of the beam splitter, and the extension direction of the phase shifter is perpendicular to the extension direction of the antenna corresponding to the phase shifter, so that when the beam splitter and the antenna are located in the X direction (the direction from each multi-way output end of the beam splitter to the corresponding antenna input end), the phase shifter is located in the Y direction, and the X direction is perpendicular to the Y direction, which can effectively reduce the length of the optical phased array in the Y direction. Furthermore, the solution of using the extension direction of the phase shifter perpendicular to the output direction of the multi-way output end of the beam splitter is also conducive to reducing the complexity of research and development.

[0069] In the second specific implementation of the embodiment of the present invention, refer to Figure 3 , Figure 3 Schematic diagram of the structure of the second optical phased array in an embodiment of the present invention.

[0070] The second optical phased array may include: a beam splitter 32, a phase shifter array 33 including a plurality of phase shifters, and an antenna array 34, wherein the beam splitter 32 may be used to split the light source signal of the light source 31 into multiple paths.

[0071] The following describes the differences between the second optical phased array and the first optical phased array.

[0072] Specifically, Figure 3The angle between the propagation direction of the optical signal in the phase shifter shown and the output direction of the multi-path output end of the optical splitter 32 is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle.

[0073] Specifically, the angle a between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter 32 is an obtuse angle, and the angle b between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle, wherein a+b=180°.

[0074] In the embodiment of the present invention, the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle, so that the phase shifter can present Figure 3 Furthermore, the beam splitter, phase shifter, and antenna are arranged in a Z shape, thereby reducing the length of the optical phased array in the Y direction while effectively reducing the length of the optical phased array in the X direction (the direction from each multi-channel output end of the beam splitter to the corresponding antenna input end).

[0075] Continue to refer to Figure 2 Furthermore, the optical phased array may also include: a plurality of first optical waveguides 25, each first optical waveguide 25 connected to the multi-path output end of the optical splitter 21 and the corresponding phase shifter; wherein the first optical waveguide 25 has a bend, and the absolute values ​​of the bend angles between the first optical waveguides 25 are equal.

[0076] In the embodiment of the present invention, by providing a first optical waveguide 25 connecting the multi-path output end of the optical splitter 21 and the corresponding phase shifter, the first optical waveguide 25 has a bend, and the absolute values ​​of the bending angles between the first optical waveguides 25 are equal, so that the optical paths from the multi-path output end of the optical splitter to the phase shifter can be kept parallel, which is conducive to better maintaining the equality of the optical path between each multi-path output end to the corresponding antenna input end.

[0077] The bending angle of the first optical waveguide 25 may be the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter, such as Figure 3 Angle a is shown.

[0078] Furthermore, the optical phased array may further include: a plurality of second optical waveguides 26, each second optical waveguide 26 connecting the phase shifter and the corresponding antenna; wherein the second optical waveguide 26 has a bend, and the absolute values ​​of the bend angles between the second optical waveguides 26 are equal.

[0079] In the embodiment of the present invention, by providing a second optical waveguide 26 connecting the phase shifter and the corresponding antenna, the second optical waveguide 26 has a bend, and the absolute values ​​of the bending angles between the second optical waveguides 26 are equal, so that the optical paths from the phase shifter to the antenna can be kept parallel, which is conducive to better maintaining the equality of the optical paths between each multi-path output terminal to the corresponding antenna input terminal.

[0080] The bending angle of the second optical waveguide 26 may be the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter, such as Figure 3 Angle b is shown.

[0081] Further, each phase shifter is connected to the first optical waveguide 25 and the second optical waveguide 26, and the lengths of the first optical waveguide 25 and the second optical waveguide 26 connected to different phase shifters are equal.

[0082] In the embodiment of the present invention, by setting the lengths of the first optical waveguide 25 and the second optical waveguide 26 connected to different phase shifters to be equal, it is possible to achieve equal optical paths from each multi-path output end of the optical splitter to the corresponding antenna input end.

[0083] Reference Figure 4 , Figure 4 4 is a schematic diagram of the structure of the third optical phased array in an embodiment of the present invention. The third optical phased array may include: a beam splitter 42, a phase shifter array 43 including a plurality of phase shifters, and an antenna array 44, wherein the beam splitter 42 may be used to split the light source signal of the light source 41 into multiple paths.

[0084] The following describes the differences between the third optical phased array and the first optical phased array.

[0085] Specifically, Figure 4 The number of phase shifters shown is an even number; the light paths output from the multi-path output end of the beam splitter 42 are divided into two groups, and the two groups of light paths are arranged axially symmetrically; the phase shifters corresponding to the multi-path output end of the beam splitter 42 are divided into two groups, and the two groups of phase shifters are arranged axially symmetrically.

[0086] In a third specific implementation of the embodiment of the present invention, the number of the phase shifters is an even number; the optical paths output from the multi-path output end of the splitter are divided into two groups, and the two groups of optical paths are arranged axially symmetrically; the phase shifters corresponding to the multi-path output end of the splitter are divided into two groups, and the two groups of phase shifters are arranged axially symmetrically, which can achieve symmetrical distribution of the optical paths, reduce the length of the optical phased array in the X direction (the direction from each multi-path output end of the splitter to the corresponding antenna input end), and provide a more flexible length-to-width ratio.

[0087] It should be pointed out that Figure 4The third specific embodiment shown is Figure 2 Compared with the first specific implementation shown, it is shorter in the X direction and longer in the Y direction, and can satisfy that the optical path between each multi-path output end of the optical splitter and the corresponding antenna input end is equal, so that the user can choose to use it according to actual needs.

[0088] Furthermore, the symmetry axes of the two groups of optical paths and the symmetry axes of the two groups of phase shifters may be parallel.

[0089] like Figure 4 In the phase shifters shown, the upper half (such as the 4 above) phase shifters are a group, which are symmetrically distributed with the lower half (such as the 4 below) phase shifters, the optical paths output from the multi-way output terminals T1 to T4 of the splitter are a group, which are connected to the upper half phase shifters, and the optical paths output from the multi-way output terminals T5 to T8 of the splitter are another group, which are connected to the lower half phase shifters.

[0090] Furthermore, the symmetry axes of the two groups of optical paths and the symmetry axes of the two groups of phase shifters can both be lines connecting the input end of the optical splitter 42 to the center points of the multiple access ends of the antenna array 44 .

[0091] In an embodiment of the present invention, by setting the symmetry axes of the two groups of optical paths and the symmetry axes of the two groups of phase shifters to be the connecting lines from the input end of the splitter 42 to the center points of the multiple access ends of the antenna array 44, it can be better ensured that the optical path between each multi-path output end of the splitter to the corresponding antenna input end is equal, thereby satisfying the requirements of compact layout and consistent waveguide length of each channel at the same time.

[0092] Furthermore, the beam splitter 42 and the antenna array 44 are equally divided into two groups, and the beam splitter 42, the phase shifter corresponding to the multi-channel output end of the beam splitter 42, the optical path output from the multi-channel output end of the beam splitter 42 and the antenna array 44 use the same symmetry axis.

[0093] In the embodiment of the present invention, on the basis of setting the optical paths output from the multi-path output end of the optical splitter 42 to be equally divided into two groups and the phase shifters corresponding to the multi-path output end of the optical splitter 42 to be equally divided into two groups, by setting the optical splitter 42 and the antenna array 44 to be equally divided into two groups and using the same symmetry axis, it can be achieved Figure 4 Specific embodiments shown.

[0094] In a third specific implementation of the embodiment of the present invention, Figure 4 As shown, the extending direction of the phase shifter is perpendicular to the output direction of the multi-path output end of the optical splitter 42, and the extending direction of the phase shifter is perpendicular to the extending direction of the antenna corresponding to the phase shifter.

[0095] Specifically, the extension direction of the phase shifter is perpendicular to the output direction of the multi-way output end of the beam splitter 42, and the extension direction of the phase shifter is perpendicular to the extension direction of the antenna corresponding to the phase shifter, so that when the beam splitter and the antenna are located in the X direction (the direction from each multi-way output end of the beam splitter to the corresponding antenna input end), the phase shifter is located in the Y direction, and the X direction is perpendicular to the Y direction, which can effectively reduce the length of the optical phased array in the Y direction. Furthermore, the solution of using the extension direction of the phase shifter perpendicular to the output direction of the multi-way output end of the beam splitter is also conducive to reducing the complexity of research and development.

[0096] In a fourth specific implementation of the embodiment of the present invention, refer to Figure 5 , Figure 5 Schematic diagram of the structure of the fourth optical phased array in an embodiment of the present invention.

[0097] The fourth optical phased array may include: a beam splitter 52, a phase shifter array 53 including a plurality of phase shifters, and an antenna array 54, wherein the beam splitter 52 may be used to split the light source signal of the light source 51 into multiple paths.

[0098] The following is an analysis of the fourth type of optical phased array. Figure 4 The different contents of the third optical phased array are illustrated.

[0099] Specifically, Figure 5 The angle between the propagation direction of the optical signal in the phase shifter shown and the output direction of the multi-path output end of the optical splitter 52 is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle.

[0100] Specifically, the angle between the propagation direction of the optical signal in the upper half (such as the four above) phase shifters and the output direction of the upper half output end of the optical splitter 52 (refer to Figure 3 The angle a) in the diagram is an obtuse angle, and the angle between the propagation direction of the optical signal in the lower half (such as the following 4) phase shifter and the output direction of the lower half output end of the optical splitter 52 (symmetrical to the angle a, with the axis of symmetry being the same as the axis of symmetry of the phase shifter) is an obtuse angle.

[0101] The angle between the propagation direction of the optical signal in the phase shifter in the lower part (such as the following 4) and the propagation direction of the optical signal in the antenna corresponding to the phase shifter (refer to Figure 3 The angle b) in the phase shifter is an acute angle, and the angle between the propagation direction of the optical signal in the phase shifter in the upper part (such as the 4 above) and the propagation direction of the optical signal in the antenna corresponding to the phase shifter (symmetrical to the angle a, with the axis of symmetry being the same as the axis of symmetry of the phase shifter) is an acute angle.

[0102] In the embodiment of the present invention, the angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle, so that the upper half of the phase shifter can present Figure 5 The lower half of the phase shifter is shown tilted from upper right to lower left. Figure 5 Furthermore, the beam splitter, phase shifter, and antenna are arranged in a Z shape, thereby reducing the length of the optical phased array in the Y direction while effectively reducing the length of the optical phased array in the X direction (the direction from each multi-channel output end of the beam splitter to the corresponding antenna input end).

[0103] Reference Figure 6 , Figure 6 It is a schematic diagram of two-dimensional scanning phase calibration in an embodiment of the present invention.

[0104] like Figure 6 As shown, by adjusting the optical phase, the beam scanning in the array direction (Y direction) can be achieved, while changing the incident wavelength can achieve the beam scanning in the antenna direction (X direction). Using a phased array with the same waveguide length in each channel, only one set of phase calibration is required for the n columns in the array direction (Y direction), that is, the kth column.

[0105] Since in the embodiment of the present invention, the optical paths from each multi-path output end of the optical splitter to the corresponding antenna input end are equal, the phase difference caused by different wavelengths in the transmission process of the light field can be approximately zero. By changing the wavelength of the input light, m ​​rows can be scanned in another direction (X direction) without additional calibration, thus realizing two-dimensional scanning and greatly saving phase calibration time.

[0106] Furthermore, in an embodiment of the present invention, each layer of the splitting structure can be set to include one or more 1×2 tree structures, and the optical path between each branch link splitter unit and the main link splitter unit in the same layer of the splitting structure is equal, so that the optical path between each channel from the splitter input end to the splitter output end is consistent, so that the optical signals of the optical phased array are equal not only in the optical path between the splitter output end and the antenna input end, but also in the optical path before the splitter output end. Therefore, the phase difference caused by different wavelengths in the light field during transmission is further reduced, which better saves the phase calibration time and improves the phase calibration accuracy.

[0107] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. An optical phased array, characterized in that: include: An optical splitter is used to divide the light source signal into multiple paths; A plurality of phase shifters are coupled to the multi-path output ends of the optical splitter in a one-to-one correspondence, and are used to respectively receive the multi-path optical signals after the optical splitting and perform phase shift processing; An antenna array, comprising a plurality of antennas, wherein the plurality of antennas are coupled to the plurality of phase shifters in a one-to-one correspondence, and are used to receive the optical signal after phase shift processing; Wherein, the optical path from each multi-channel output end of the optical splitter to the corresponding antenna input end is equal; The number of the phase shifters is an even number; The light paths output from the multi-path output end of the optical splitter are divided into two groups, and the two groups of light paths are arranged axially symmetrically; The phase shifters corresponding to the multi-channel output ends of the optical splitter are divided into two groups, and the two groups of phase shifters are arranged in an axisymmetric manner.

2. The optical phased array according to claim 1, characterized in that: The extending direction of the phase shifter is different from the output direction of the multi-path output end of the optical splitter, and the extending direction of the phase shifter is different from the extending direction of the corresponding antenna.

3. The optical phased array according to claim 1, characterized in that: The optical splitter includes a main link optical splitter unit and a multi-layer optical splitting structure, each layer of the optical splitting structure includes a plurality of branch link optical splitter units; Each layer of the optical splitting structure includes one or more 1×2 tree structures, and the optical paths between each branch link optical splitter unit and the main link optical splitter unit in the same layer of the optical splitting structure are equal.

4. The optical phased array according to claim 1, characterized in that: The symmetry axes of the two groups of optical paths are parallel to the symmetry axes of the two groups of phase shifters.

5. The optical phased array according to claim 4, characterized in that: The symmetry axes of the two groups of optical paths and the symmetry axes of the two groups of phase shifters are both lines connecting the input end of the optical splitter to the center points of the multiple access ends of the antenna array.

6. The optical phased array according to claim 5, characterized in that: The optical splitter and antenna array are equally divided into two groups, and the optical splitter, the phase shifter corresponding to the multi-path output end of the optical splitter, the optical path output from the multi-path output end of the optical splitter and the antenna array use the same symmetry axis.

7. The optical phased array according to any one of claims 1, 4 to 6, characterized in that: The extending direction of the phase shifter is perpendicular to the output direction of the multi-path output end of the optical splitter, and the extending direction of the phase shifter is perpendicular to the extending direction of the antenna corresponding to the phase shifter.

8. The optical phased array according to any one of claims 1, 4 to 6, characterized in that: The angle between the propagation direction of the optical signal in the phase shifter and the output direction of the multi-path output end of the optical splitter is an obtuse angle, and the angle between the propagation direction of the optical signal in the phase shifter and the propagation direction of the optical signal in the antenna corresponding to the phase shifter is an acute angle.

9. The optical phased array according to claim 1, characterized in that: Also includes: A plurality of first optical waveguides, each of which is connected to a multi-path output end of the optical splitter and a corresponding phase shifter; The first optical waveguide has a bend, and the absolute values ​​of the bend angles between the first optical waveguides are equal.

10. The optical phased array according to claim 1, characterized in that: Also includes: A plurality of second optical waveguides, each second optical waveguide connecting the phase shifter and a corresponding antenna; The second optical waveguide has a bend, and the absolute values ​​of the bend angles between the second optical waveguides are equal.

11. The optical phased array according to claim 1, characterized in that: The output direction of the multi-path output end of the optical splitter is the same as the extension direction of the corresponding antenna.

12. The optical phased array according to claim 1, characterized in that: The spacing between adjacent antennas in the antenna array is equal to the spacing between adjacent light output ends of the optical splitter.

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