Beam controller and beam control method

Abstract

The present invention relates to an optical phased array-based beam controller. The beam controller includes an optical phased array, a free-space focusing region, and a shared optical grid emitter. The optical phased array includes a beam splitter and a waveguide array coupled to the beam splitter. The beam splitter is configured to equally divide an initial beam into a plurality of sub-beams. The waveguide array includes a plurality of waveguides arranged in one-to-one correspondence with the sub-beams. The waveguides are configured to transmit and receive the sub-beams. The transmitting tails of the plurality of waveguides are fan-shaped and converge to the free-space focusing region. The free-space focusing region is configured to combine the plurality of sub-beams on an image plane. The shared optical grid emitter is configured to diffract and emit a combined beam of the plurality of sub-beams on an image plane. The beam controller can control the combined beam to achieve large-angle emission and at the same time have high scanning output efficiency.

Description

[Technical field]

[0001] The present invention relates to the field of optical communication technology, and more particularly to a beam controller and a beam control method. [Background technology]

[0002] Beam control is one of the key technologies in fields such as laser radar and free-space optical communication, and can also be applied to fields such as holographic displays and biological imaging. Currently, with the development of silicon-based photonics technology, beam control is realized using optical phased arrays (OPAs), which can have the advantages of small size, high speed, and light weight.

[0003] For example, an optical phased array (OPA) includes a star coupler or beam splitter and a waveguide array coupled to the star coupler or beam splitter. The waveguide array is composed of N parallel aligned waveguides, each integrated with a controllable phase shifter, and each waveguide further coupled to a second-order linear optical grating. A number of second-order linear optical gratings are equally spaced to form a one-dimensional optical antenna array that functions as a laser output device.

[0004] However, optical phased arrays (OPAs) usually operate in the micron-scale wavelength range. In order to make the divergence angle of the beam launched by the second-order linear grating as small as possible, a weak optical grating is usually used to launch the beam transmitted by the waveguide perpendicular to the waveguide surface at a relatively long distance. Due to the large size of the weak optical grating, on the premise of ensuring that the side lobe of the optical grating does not occur during beam scanning, the distance between adjacent second-order linear optical gratings is relatively small, which makes it easy to generate coupling crosstalk between the corresponding parallel-arranged waveguides. In addition, the longer the transmission distance of the waveguide, the greater the crosstalk that occurs. This has a significant impact on the optical performance of the optical phased array, such as reducing the launch angle and reducing the scanning output efficiency. Summary of the Invention [Problem to be solved by the invention]

[0005] Based on this, embodiments of the present invention provide a beam controller and a beam control method that can control a combined beam to achieve a large angle of ejection while at the same time having high scanning power efficiency. [Means for solving the problem]

[0006] In order to achieve the above object, on the other hand, an embodiment of the present invention provides a beam controller. The beam controller includes an optical phased array, a free-space focusing region, and a shared optical grating emitter. The optical phased array includes a beam splitter and a waveguide array coupled to the beam splitter. The beam splitter is configured to equally divide an initial beam into a plurality of sub-beams. The waveguide array includes a plurality of waveguides arranged in one-to-one correspondence with the sub-beams. The waveguides are configured to transmit and receive the sub-beams. The transmitting tails of the plurality of waveguides are focused in a fan shape in the free-space focusing region. The free-space focusing region is configured to combine the plurality of sub-beams on an image plane. The shared optical grating emitter is configured to diffract and emit a combined beam obtained by combining the plurality of sub-beams on an image plane. Effect of the Invention

[0007] In the embodiment of the present invention, the synthesis of multiple sub-beams and the launch of the synthetic beam are performed separately and independently, that is, the synthesis of the sub-beams is completed by free focusing in the free space focusing region, and the launch of the corresponding synthetic beam is completed by the diffraction of the shared optical grating emitter. In this way, the structure of the shared optical grating emitter only needs to be designed for the launch requirement of the synthetic beam, and does not need to be limited by the requirement of the sub-beam synthesis, that is, it does not need to simultaneously combine the function of focusing multiple sub-beams into a synthetic beam and the function of diffracting and launching the synthetic beam. This allows the shared optical grating emitter to have a larger beam launch angle.

[0008] In addition, the transmission tails of the multiple waveguides are concentrated in the free space focusing region in a fan shape, and the distance between the transmission tails of the waveguides can be gradually reduced on the basis of not affecting the transmission effect of the main transmission part in the waveguide, for example, the distance between the output ends of two adjacent waveguides is less than the wavelength of the initial beam or less than half the wavelength of the initial beam. Here, the output end of the waveguide is the end of the boundary between the transmission tails and the free space light synthesis region. This can effectively suppress the generation of optical grating side lobes in the synthesis beam after the multiple sub-beams are focused, and ensure or improve the scanning output efficiency of the beam controller.

[0009] In summary, the beam controller provided by the embodiment of the present invention can control the composite beam to achieve large angle emission and at the same time have high scanning output efficiency.

[0010] In some embodiments, the orthogonal projection of the image plane onto the reference surface includes a circular arc line with a radius of curvature R. The orthogonal projection of the free space convergence region onto the reference surface includes a Rowland circle with a radius of curvature 2R, the center of the Rowland circle being located on said circular arc line.

[0011] In some embodiments, the distance between the output ends of two adjacent waveguides is less than the wavelength of the initial beam. Optionally, the distance between the output ends of each two adjacent waveguides is equal. In this way, by making multiple waveguides in the waveguide array have the same output distance, the difference in transmission distance between two waveguides can be easily designed and controlled.

[0012] In some embodiments, the product of the difference between the transmission distances of two adjacent waveguides and the group index of the waveguide is an integer multiple of the wavelength of the initial beam. In this way, the multiple sub-beams transmitted by the multiple waveguides can easily undergo spatial diffraction superposition in the free-space focusing region and be focused to form a composite beam at the image plane.

[0013] In some other embodiments, the beam splitter includes a plurality of cascaded 1×2 waveguide beam splitters, the waveguides including a transmit head portion and a transmit tail portion connected in series, the transmit head portions of the plurality of waveguides are arranged in parallel, and a distance between two adjacent transmit head portions is greater than a second threshold value.

[0014] The first and second thresholds can be selected and set according to actual needs, and the distance between the transmission sections where two adjacent waveguides are installed in parallel is limited so as not to cause coupling crosstalk for the transmission of the sub-beams.

[0015] In some embodiments, the waveguide array further comprises a controllable phase shifter integrated on each waveguide, the controllable phase shifter configured to control the phase of the sub-beams.

[0016] Optionally, the controllable phase shifter includes a metallic heating layer disposed on each waveguide.

[0017] Optionally, the waveguide is a doped waveguide and the controllable phase shifter comprises metal electrodes connected to the doped waveguide.

[0018] In some embodiments, the waveguide array further comprises a variable optical attenuator integrated into each waveguide, the variable optical attenuator being configured to adjust the transmit power of the waveguide, such that the variable optical attenuator can be utilized to control the intensity of the sub-beams to achieve any form of beam combining.

[0019] In some embodiments, the present invention provides a beam control method for applying to the beam controller of the above-mentioned embodiments, the beam control method including the steps of: A beam splitter splits the initial beam into multiple equal sub-beams and sends one sub-beam to one waveguide. A number of waveguides transmit respective sub-beams into a free-space focusing region. The multiple sub-beams are combined onto an image plane within a free-space focusing region. A shared optical grating emitter diffracts and emits a combined beam that combines the multiple sub-beams onto an image plane.

[0020] In some embodiments, the beam control method further comprises the steps of: The wavelength of the initial beam is adjusted to vary a scan angle of the combined beam along a first direction, and the phase of the sub-beam is adjusted to vary a scan angle of the combined beam along a second direction, where the first direction is orthogonal to the second direction.

[0021] The beam control method provided by the embodiments of the present invention is applied to the beam controller of some of the embodiments. The technical effects that can be achieved by the beam controller can also be achieved by the beam control method, and will not be described in detail herein. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a plan view of a beam controller provided by an embodiment; [Diagram 2] FIG. 2 is a plan view of another beam controller provided by an embodiment; [Diagram 3] FIG. 2 is a structural diagram of a free space focusing region provided by an embodiment; [Figure 4] FIG. 2 is a structural illustration of a shared optical grid emitter provided by an embodiment. [Diagram 5] FIG. 2 is a structural diagram of a waveguide array provided by an embodiment; [Figure 6] FIG. 2 is an illustration of a combined optical path and an exit optical path of an initial beam provided by an embodiment. [Figure 7] FIG. 13 is an illustration of a synthesis optical path and an exit optical path of another initial beam provided by an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] In order to facilitate understanding of the present invention, the present invention will be described more completely below with reference to the accompanying drawings, in which embodiments of the present invention are shown. However, the present invention can be embodied in many different forms and is not limited to the embodiments set forth herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more detailed and complete.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to be limiting of the present invention.

[0025] It is noted that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intermediate elements or layers present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intermediate elements or layers present.

[0026] In addition, although terms such as first, second, and third may be used to describe various elements, members, regions, layers, and / or portions, these elements, members, regions, layers, and / or portions should not be limited by these terms. These terms merely distinguish one element, member, region, layer, or portion from another element, member, region, layer, or portion. Thus, without departing from the teachings of the present invention, a first element, member, region, layer, or portion described below may be expressed as a second element, member, region, layer, or portion.

[0027] Spatial relationship terms, such as "under", "below", "below", "below", "above", "above" and the like, may be used herein to describe the relationship of one element or feature to another element or feature shown in the figures. It should be noted that the spatial relationship terms also include different orientations of the device during use and operation, other than the orientation shown in the figures. For example, if the device in the figures is inverted, an element or feature described as "under" or "below" another element or feature would be oriented "above" the other element or feature. Thus, the exemplary terms "under" and "below" can include two orientations: above and below. Also, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatial terms used herein would be interpreted accordingly.

[0028] Where used, the singular forms "a", "one" and "said" can include the plural forms as well, unless the context clearly dictates otherwise. Additionally, terms such as "comprising" or "having" specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, as used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0029] The embodiments of the present invention will now be described with reference to cross-sectional views as illustrations of preferred embodiments (and intermediate structures) of the present invention, although variations in shape, e.g., due to manufacturing techniques and / or tolerances, are to be expected. Thus, embodiments of the present invention are not limited to the particular shapes of regions illustrated herein, but include deviations in shapes, e.g., due to manufacturing techniques. The illustrated regions are illustrative in nature, and their shapes are not intended to represent the actual shapes of regions on a device and are not intended to limit the scope of the present invention.

[0030] 1 and 2, some embodiments of the present invention provide an optical phased array-based beam controller 100. The beam controller 100 includes an optical phased array 1, a free-space focusing region 2, and a shared optical grating emitter 3. The optical phased array 1 includes a beam splitter 11 and a waveguide array 12 coupled to the beam splitter 11. The beam splitter 11 is configured to equally divide an initial beam into a plurality of sub-beams. The waveguide array 12 includes a plurality of waveguides 120 arranged in one-to-one correspondence with the sub-beams. The waveguides 120 are configured to transmit and receive the sub-beams. The transmitting tails of the plurality of waveguides 120 are focused in a fan shape into the free-space optical combining region 2. The free-space focusing region 2 is configured to combine the plurality of sub-beams on an image plane S0. The shared optical grating emitter 3 is configured to diffract and launch the combined beam, which is formed by combining the plurality of sub-beams on the image plane S0.

[0031] The beam splitter 11 may be a star coupler or may be configured with multiple cascaded 1x2 waveguide beam splitters. The beam splitter 11 is configured to split the initial beam equally into multiple sub-beams and has at least one input end and multiple output ends. The input end of the beam splitter 11 is coupled to the light source, and one output end of the beam splitter 11 outputs one of the sub-beams correspondingly.

[0032] Optionally, the light source is a laser chip, and the light beam emitted by the light source is a near-infrared light beam with a wavelength between 950 and 1550 nm. The light beam sent from the light source to the beam splitter 11 is an initial beam, and the wavelength of the initial beam is adjustable by the light source.

[0033] The number of waveguides 120 in the waveguide array 12 corresponds to the number of output ends of the beam splitter 11, for example, they are the same. The waveguides 120 are planar optical waveguides. The beam splitter 11 and the waveguide array 12 can be made of materials such as silicon dioxide (SiO2), glass, lithium niobate (LiNbO3), III-V semiconductor compounds, silicon-on-insulator (SOI / SIMOX), silicon nitride (SiN), silicon oxynitride (SiON), polymer, etc.

[0034] Depending on the difference in the structure of the beam splitter 11, the structure of the waveguide 120 also differs.

[0035] In some examples, as shown in FIG. 1, the beam splitter 11 is a star coupler, and the multiple output ends of the beam splitter 11 are distributed along a circumference. The waveguide 120 includes a transmission head portion 1210, a transmission intermediate portion 1215, and a transmission tail portion 1220 connected in sequence. The transmission head portions 1210 of the multiple waveguides 120 are converged to the star coupler in a fan shape, and the transmission head portion 1210 of one waveguide 120 is correspondingly connected to one output end of the star coupler. The transmission intermediate portions 1215 of the multiple waveguides 120 are arranged in parallel, and the distance D1 between two adjacent transmission intermediate portions 1215 is greater than a first threshold. The transmission tail portions of the multiple waveguides 120 are converged to the free space light combining region 2 in a fan shape.

[0036] In another example, as shown in Fig. 2, the beam splitter 11 is configured by cascading a plurality of 1x2 waveguide beam splitters 111, and a plurality of output ends of the beam splitter 11 are arranged in parallel. The waveguide 120 includes a transmission head portion 1210 and a transmission tail portion 1220 connected in sequence. The transmission head portions 1210 of the plurality of waveguides 120 are arranged in parallel, and the distance D2 between two adjacent transmission head portions 1210 is greater than a second threshold value.

[0037] Here, it can be understood that the transmission distance of the waveguide 120 is usually long, but in order to make the main transmission part of the waveguide 120 the transmission part where adjacent waveguides 120 are installed in parallel, for example, the transmission middle part 1215 in FIG. 1 or the transmission head part 1210 in FIG. 2, the length of the transmission tail part 1220 of the waveguide 120 must be set as short as possible. Based on this, the first threshold and the second threshold can be selected and set according to actual needs, and the interval between the transmission parts where two adjacent waveguides 120 are installed in parallel is limited so as not to cause coupling crosstalk in the transmission of the sub-beam. Because the length of the transmission tail part 1220 of the waveguide 120 is short, the transmission tail parts 1220 of the multiple waveguides 120 are concentrated in a fan shape, and the distance between the two adjacent transmission tail parts 1220 is gradually narrowed, but the coupling crosstalk between the two adjacent transmission tail parts 1220 in the transmission of the sub-beam can be ignored.

[0038] In an embodiment of the present invention, the transmission tails of the multiple waveguides 120 are fan-shaped and converge to the free space focusing region 2, and the synthesis of the multiple sub-beams output by the waveguide array 12 can be completed in the free space focusing region 2, for example, the multiple sub-beams focus to an image plane S0, which is a virtual imaging plane after the multiple sub-beams are defocused in the free space focusing region 2. The free space focusing region 2 is a free propagation region (FPR).

[0039] Alternatively, as shown in FIG. 3, the image surface S0 is an arc surface, and the orthogonal projection shape of the image surface S0 on the reference surface is an arc line L with a radius of curvature R. a Correspondingly, the orthogonal projection of the free space convergence region 2 onto the reference plane is a Rowland circle R with radius 2R. c The Rowland circle R c The center O1 of the arc line L a Located at the top.

[0040] Here, the reference plane refers to a plane parallel to the plane on which the waveguide array 12 is arranged, such as the horizontal plane shown in Figures 1, 2 and 3. Furthermore, based on this, the transmission tail parts of the multiple waveguides 120 are concentrated in the free space light combining region 2 in a fan shape, which means that the output ends of the multiple waveguides 120 are aligned in the Rowland circle R. c This refers to the distribution of the population along the circumference of a circle.

[0041] In the embodiment of the present invention, the shared optical grating emitter 3 is configured to diffract and emit a composite beam obtained by combining multiple sub-beams on the image plane S0, and may adopt a concentric two-stage optical grating structure. For example, as shown in FIG. 4, the shared optical grating emitter 3 is composed of multiple arc-shaped teeth 31 with the same curvature center O3. In the embodiment of the present invention, as long as the composite optical beam can be directly emitted from the image plane S0 into the shared optical grating emitter 3, the number of arc-shaped teeth 31, the radius of curvature, etc. are not limited.

[0042] Alternatively, the image plane S0 is located in a region bounded by the arc-shaped tooth 31 and its center of curvature O3. For example, in conjunction with Figures 3 and 4, it should be understood that the center of curvature O2 of the image plane S0 is the same as the center of curvature O3 of the arc-shaped tooth 31. Alternatively, as another example, with continued reference to Figures 3 and 4, it should be understood that the image plane S0 overlaps with the inner surface of the arc-shaped tooth 31 that has the smallest radius of curvature in the shared light grating emitter 3.

[0043] In this way, the composite beam obtained by combining multiple sub-beams on the image plane S0 can be transmitted linearly along the focus direction to the shared optical lattice emitter 3, and diffracted and emitted by the shared optical lattice emitter 3. That is, the composite beam obtained by focusing multiple sub-beams on the image plane S0 is transmitted to the shared optical lattice emitter 3 along the light emission direction perpendicular to the circumferential direction of the image plane S0. The shared optical lattice emitter 3 has a wavelength selection function, and under the condition that the wavelength of the composite beam satisfies the optical lattice equation of the shared optical lattice emitter 3, the composite beam can achieve diffraction and emission at a certain angle through the shared optical lattice emitter 3. In addition, when the wavelengths and phases of the initial beams are different, the position at which the corresponding composite beam is focused on the image plane S0 and the emission angle of the composite beam are also different. The shared optical grating emitter 3 employs a plurality of concentrically arranged arc-shaped teeth 31, and by positioning the image plane S0 in the area surrounded by the arc-shaped teeth 31 and their center of curvature O3, the plurality of arc-shaped teeth 31 can be diffracted as a whole and emitted to a composite beam at any position on the image plane S0.

[0044] In addition, by adopting the above structure, the shared optical grating emitter 3 does not cause coupling crosstalk in the diffraction and emission of the composite beam due to the size of the gap between two adjacent arc-shaped teeth 31. In this way, the number of waveguides 120 in the waveguide array 12 does not need to be reduced as much as possible because the size of the shared optical grating emitter 3 is small, which is advantageous for improving the transmission power of the beam controller 100.

[0045] In summary, in the embodiment of the present invention, the synthesis of multiple sub-beams and the emission of the synthetic beam are performed independently, that is, the synthesis of multiple sub-beams is completed by free focusing in the free space focusing region 2, and the emission of the corresponding synthetic beam is completed by diffraction by the shared optical grating emitter 3. In this way, the structure of the shared optical grating emitter 3 can be designed according to the need of the emission of the synthetic beam, and no longer needs to be limited by the need of sub-beam synthesis, that is, it does not need to simultaneously combine the function of focusing multiple sub-beams into a synthetic beam and the function of diffracting and launching the synthetic beam. Therefore, the shared optical grating emitter 3 can have a larger beam emission angle.

[0046] In addition, since the transmission tail portions of the multiple waveguides 120 are fan-shaped and concentrated in the free space focusing region 2, the interval between the transmission tail portions 1220 of the waveguides 120 can be gradually reduced without affecting the transmission effect of the main transmission portion, for example, the distance between the output ends of two adjacent waveguides 120 is smaller than the wavelength of the initial beam or smaller than half the wavelength of the initial beam. Here, the output end of the waveguide 120 is the end of the boundary between the transmission tail portions 1220 and the free space light synthesis region 2. Therefore, the generation of optical grating side lobes in the synthesis beam after focusing of multiple sub-beams can be effectively suppressed, and the scanning output efficiency of the beam controller 100 can be ensured or improved.

[0047] It should be noted that in one possible embodiment, the product of the difference in the transmission distances of two adjacent waveguides 120 and the group refractive index of the waveguides 120 is an integer multiple of the wavelength of the initial beam. In this way, the multiple sub-beams transmitted by the multiple waveguides 120 are easily spatially diffracted and superimposed in the free-space focusing region 2 and focused into a composite beam on the image plane S0.

[0048] On this basis, optionally, as shown in FIG. 5, the distance D3 between the output ends of each two adjacent waveguides 120 is equal, and by having the same output spacing for multiple waveguides 120 in the waveguide array 12, it becomes easy to design and control based on the difference in transmission distance between two adjacent waveguides 120.

[0049] 5, in some embodiments, the waveguide array 12 further includes a controllable phase shifter 121 integrated on each waveguide 120. The controllable phase shifter 121 is configured to control the phase of the sub-beam. In this manner, the relative phase distribution of multiple sub-beams in the waveguide array 12 can be controlled by adjusting the phase of the sub-beam using the controllable phase shifter 121.

[0050] The structure of the controllable phase shifter 121 can be selected and set according to actual needs. For example, the controllable phase shifter 121 is a metal heating layer disposed on each waveguide 120, thus the phase of the corresponding sub-beam can be controlled by the heating temperature provided by the metal heating layer. Or, as another example, the waveguide 120 is a doped waveguide, and the controllable phase shifter 121 is a metal electrode connected to the waveguide 120, thus the phase of the corresponding sub-beam can be controlled by the electric signal sent by the metal electrode.

[0051] From the above, by adjusting the wavelength of the initial beam, the emission angle of the composite beam can be changed in the vertical plane, and the composite beam can be scanned in a first direction (e.g., vertical direction). The wavelength of the initial beam can determine the vertical scanning angle of the composite beam. By controlling the phase change of the corresponding sub-beam by the controllable phase shifter 121, the composite beam can be focused at different positions along the circumferential direction of the image surface S0 in the horizontal plane, and horizontal scanning of the composite beam can be realized. The phase of the sub-beam can determine the scanning angle of the composite beam in a second direction (e.g., horizontal direction). Moreover, the adjustment of the initial beam wavelength and the adjustment of the sub-beam phase can be performed selectively or simultaneously.

[0052] To more clearly illustrate the effects of different wavelengths and different phases on the composite beam, FIG. 6 and FIG. 7 respectively show the optical paths of two composite beams under different wavelengths and different phase control.

[0053] As shown in Fig. 6, the wavelength of the initial beam is λ1, and the phase control of the sub-beams adopts the first control method. The multiple sub-beams transmitted to the free space focusing region 2 by the waveguide array 12 are diffracted and superimposed in the free space, and can be focused at the point A position on the image plane S0 (as shown in Fig. 6(a)), and can be emitted from the horizontal plane (i.e., the surface of the beam controller 100) at an included angle α1 under the action of the shared optical grating emitter 3 (as shown in Fig. 6(b)).

[0054] As shown in Fig. 7, the wavelength of the initial beam is λ2, and the phase control of the sub-beams adopts the second control method, where λ2 ≠ λ1, and the first control method is different from the second control method. The multiple sub-beams transmitted to the free space focusing region 2 by the waveguide array 12 can be diffracted and superimposed in the free space and focused at the B point position on the image plane S0 (as shown in Fig. 7(a)), and can be emitted from the horizontal plane (i.e., the surface of the beam controller 100) at an included angle α2 under the action of the shared optical grating emitter 3 (as shown in Fig. 7(b)).

[0055] 5, in some embodiments, the waveguide array 12 further includes a variable optical attenuator (VOA) 122 integrated into each waveguide 120. The variable optical attenuator 122 is configured to adjust the transmission power of the waveguide 120. Thus, the variable optical attenuator 122 can be used to control the intensity of the sub-beams to realize any form of beam combining.

[0056] The structure of the variable optical attenuator 122 can be selected and set according to actual needs. Optionally, the variable optical attenuator 122 is made of a Mach-Zehnder interferometer (MZI). By using the Mach-Zehnder interferometer (MZI) to adjust the phase of the sub-beam, any ratio of power attenuation can be realized.

[0057] Some embodiments of the present invention provide a beam control method which is applied to the beam controller 100 in some of the above-described embodiments. The beam control method includes steps S100 to S400.

[0058] In S100, beam splitter 11 splits the initial beam into multiple equal sub-beams and transmits each sub-beam into waveguide 120.

[0059] Here, beam splitter 11 may be a star coupler or may be composed of multiple cascaded 1×2 waveguide beam splitters. The input end of beam splitter 11 is coupled to the light source, and the output end of beam splitter 11 is coupled to waveguide 120.

[0060] The light source may be, for example, a laser chip, and the beam emitted by the light source may be a near-infrared light beam having a wavelength between 950 and 1550 nm. The beam transmitted from the light source to the beam splitter 11 is an initial beam, and the wavelength of the initial beam can be adjusted by the light source.

[0061] At S200, the plurality of waveguides 120 transmit corresponding sub-beams to a free-space focusing region 2.

[0062] Here, the transmitting tails of the multiple waveguides 120 are concentrated in the free space light combining region 2 in a sector shape.

[0063] In addition, the transmission distance of the waveguide 120 is generally relatively long, but it can be understood that the length of the transmission tail portion 1220 of the waveguide 120 must be set as short as possible in order to make the main transmission portion of the waveguide 120 a transmission portion installed in parallel with the adjacent waveguide 120, for example, the transmission middle portion 1215 in FIG. 1 or the transmission head portion 1210 in FIG. 2. Based on this, the interval between the parallel transmission portions of the adjacent waveguides 120 is limited so as not to cause coupling crosstalk for the transmission of the sub-beam. Since the length of the transmission tail portion 1220 of the waveguide 120 is relatively short, the transmission tail portions 1220 of the multiple waveguides 120 are concentrated in a fan shape, and the distance between the two adjacent transmission tail portions 1220 is gradually reduced, but the coupling crosstalk for the sub-beam transmission between the two adjacent transmission tail portions 1220 can be neglected.

[0064] In S300, multiple sub-beams are combined onto an image plane S0 in the free space focusing region 2.

[0065] The transmission tails of the multiple waveguides 120 are focused into the free-space focusing region 2 in a fan shape, so that the synthesis of the multiple sub-beams output by the waveguide array 12 can be completed within the free-space focusing region 2, for example, by directing the multiple sub-beams to the image plane S O The image plane S0 is a virtual image plane after the multiple sub-beams are focused in the free space focusing region 2. The free space focusing region 2 is a free propagation region (FPR for short).

[0066] In S400, the shared optical grating emitter 3 diffracts and emits a composite beam obtained by combining the multiple sub-beams onto an image plane S0.

[0067] The composite beam, which is a combination of multiple sub-beams on the image plane S0, is transmitted linearly along the focus direction to the shared optical lattice emitter 3 and is diffracted and emitted by the shared optical lattice emitter 3. That is, the composite beam, which is focused on the image plane S0 by multiple sub-beams, is transmitted to the shared optical lattice emitter 3 along the light emission direction perpendicular to the circumferential direction of the image plane S0. The shared optical lattice emitter 3 has a wavelength selection function, and under the condition that the wavelength of the composite beam satisfies the optical lattice equation of the shared optical lattice emitter 3, the composite beam is diffracted and emitted at a certain angle through the shared optical lattice emitter 3. In addition, when the wavelength and phase of the initial beam are different, the position where the composite light beam is focused on the image plane S0 and the emission angle of the composite beam are correspondingly different.

[0068] The beam control method provided by the embodiments of the present invention is applied to the beam controller of some of the above-mentioned embodiments. The technical effects that can be achieved by the above-mentioned beam controller can also be achieved by the beam control method, so they will not be described in detail here.

[0069] In some embodiments, the beam control method further includes S500.

[0070] In S500, a wavelength of the initial beam is adjusted to vary a scan angle of the composite beam along a first direction, and a phase of the sub-beam is adjusted to vary a scan angle of the composite beam along a second direction, where the first direction is orthogonal to the second direction.

[0071] Here, the wavelength of the initial beam can be adjusted by controlling the light source.

[0072] The phase of the sub-beams can be realized by a controllable phase shifter 121 integrated on each waveguide 120. For example, the controllable phase shifter 121 can be a metal heating layer disposed on each waveguide 120, thus controlling the phase of the corresponding sub-beam by the heating temperature provided by the metal heating layer. Alternatively, as another example, the waveguides 120 can be doped waveguides and the controllable phase shifter 121 can be metal electrodes connected to each waveguide 120, thus controlling the phase of the corresponding sub-beam by the electrical signal transmitted by the metal electrodes.

[0073] The first direction is, for example, the vertical direction, and the second direction is, for example, the horizontal direction.

[0074] Furthermore, there is no necessary restriction on the order between S500, S300, and S400, that is, any of them may be executed first, or they may be executed simultaneously.

[0075] In some embodiments, the beam control method further includes S600.

[0076] In S600, the transmit power of the waveguide is adjusted to vary the intensity of the sub-beams.

[0077] Here, the transmission power of the waveguides can be achieved by a variable optical attenuator 122 integrated into each waveguide 120 .

[0078] For example, the variable optical attenuator 122 is composed of a Mach-Zehnder interferometer (MZI). By adjusting the phase of the sub-beams using the Mach-Zehnder interferometer (MZI), any ratio of power attenuation can be realized. Therefore, the intensity of the sub-beams can be controlled to realize any type of beam combining.

[0079] Furthermore, there is no essential restriction on the order between S600 and S300, S400, and S500, and any of them may be executed first, or may be executed simultaneously.

[0080] The technical features of the above embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above examples have been described. However, as long as there is no contradiction in the combination of these technical features, any combination should be considered to be within the scope described in this specification.

[0081] The above embodiments only represent some embodiments of the present invention, and the description is relatively specific and detailed, but this should not be understood as limiting the scope of the invention patent. It should be noted that those skilled in the art can make some modifications and improvements without departing from the concept of the present invention, and all of them are included in the protection scope of the present invention. Therefore, the protection scope of the invention patent should be determined by the attached claims. [Explanation of symbols]

[0082] 100 Beam Controller 1. Optical Phased Array 2. Free Space Convergence Region 3 Shared Optical Lattice Emitter 11 Beam splitter 12 Waveguide Array 120 Waveguide 1210 Transmission head part 1215 Transmission Intermediate Part 1220 Transmission tail 121 Controllable Phase Shifter 122 Variable Optical Attenuator 31 Circular tooth 111 1x2 Waveguide Beam Splitter S0 image plane L a Arc line R c Roland Yen D1 the distance between adjacent transmission intermediate parts, D2 Distance between adjacent transmission head parts D3 Distance between adjacent output ends O1 Center of Rowland Circle O2 image plane curvature center O3 Center of curvature of circular arc tooth α1 and α2 are the vertical exit angles of the composite beam under different wavelength conditions. A and B: Horizontal focus position of the combined beam under different phase conditions

Claims

1. an optical phased array, a free space focusing region, and a shared optical grating emitter, the optical phased array including a beam splitter and a waveguide array coupled to the beam splitter; the beam splitter is configured to split the initial beam equally into a plurality of sub-beams; the waveguide array includes a plurality of waveguides arranged in one-to-one correspondence with the sub-beams, the waveguides being configured to transmit and receive the sub-beams; a plurality of said waveguide transmit tails converge into a free space focusing region in a sector shape, said free space focusing region being configured to combine said plurality of said sub-beams into an image plane; a shared optical grating emitter configured to diffract and emit a combined beam that combines a plurality of said sub-beams at said image plane, said shared optical grating emitter being comprised of a plurality of concentrically arranged arcs; A beam controller, wherein the image plane is located in an area surrounded by an arc portion and its center of curvature.

2. The orthogonal projection shape of the image surface on the reference surface includes an arc line having a radius of curvature R, 2. The beam controller according to claim 1, wherein the orthogonal projection shape of said free space convergence region on said reference plane includes a Rowland circle having a radius of 2R, and the center of said Rowland circle is located on said arc line.

3. 2. The beam controller according to claim 1, wherein a distance between output ends of two adjacent said waveguides is shorter than a wavelength of said initial beam.

4. 4. The beam controller of claim 3, wherein the distance between the output ends of each of two adjacent said waveguides is equal.

5. 2. The beam controller according to claim 1, wherein a product of a difference between the transmission distances of two adjacent said waveguides and the group refractive index of said waveguide is an integer multiple of the wavelength of said initial beam.

6. the beam splitter includes a star coupler, and the waveguide includes a transmission head section, a transmission mid section, and a transmission tail section connected in sequence; The transmission head portions of the plurality of waveguides are fan-shaped and converge to the star coupler; 2. The beam controller according to claim 1, wherein the transmitting intermediate portions of the plurality of waveguides are arranged in parallel, and a distance between two adjacent transmitting intermediate portions is greater than a first threshold value.

7. the beam splitter includes a plurality of cascaded 1×2 waveguide beam splitters; 2. The beam controller of claim 1, wherein the waveguide includes a transmission head portion and a transmission tail portion connected in series, the transmission head portions of the plurality of waveguides are arranged in parallel, and the distance between two adjacent transmission head portions is greater than a second threshold value.

8. 2. The beam controller of claim 1, wherein the waveguide array further comprises a controllable phase shifter integrated on each of the waveguides, the controllable phase shifter configured to control the phase of the sub-beams.

9. the controllable phase shifter includes a metallic heating layer disposed on each of the waveguides; Alternatively, the waveguide is a doped waveguide, and the controllable phase shifter includes a metal electrode connected to the doped waveguide.

10. 2. The beam controller of claim 1, wherein the waveguide array further comprises a variable optical attenuator integrated into each of the waveguides, the variable optical attenuator configured to adjust the transmit power of the waveguide.

11. a beam splitter splitting the initial beam into a number of equal sub-beams and transmitting one of the sub-beams to one of the waveguides; a plurality of said waveguides transmitting respective corresponding said sub-beams to a free space focusing region; combining a plurality of said sub-beams within said free space focusing region onto an image plane; a shared optical grating emitter including a plurality of concentrically arranged arcuate portions diffracting and emitting a composite beam obtained by combining the plurality of sub-beams onto the image plane; Including, A beam control method, characterized in that the image plane is located in an area surrounded by an arc portion and its center of curvature.

12. The beam control method includes: adjusting a wavelength of the initial beam such that a scan angle of the composite beam varies along a first direction; adjusting the phases of the sub-beams to vary a scan angle of the combined beam along a second direction; Further comprising: The method of claim 11, wherein the first direction is orthogonal to the second direction.

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