Wide-angle beam steering system

Wide-angle beam guidance system

The invention relates to a beam guiding system, and more particularly to a wide-angle beam guiding system that can be electronically controlled.

As is well known to those skilled in the art, an optical phased array beam steering system has been described for guiding a light beam according to an electronic command signal. One of such beam directors is described in U.S. Published Patent No. 5093740, and its invention name is "Optical Beam Steerer Having Subaperture Addressing". It was announced on March 3, 1992 and the inventor is Dorschner et al .; U.S. Published Patent No. 5963682, published on October 5, 1999 and invented by Dorschner et al .; and US Published Patent No. 6704474, published on March 9, 2004, and invented by Dorschner et al., The above patents have been assigned to this patent The assignee of the application, the entire subject matter of all such US patents is incorporated herein by reference. As described in the aforementioned patents, the beam director includes an array of optical phase shifters. The phase shift of the beam provided to the optical energy through the portion of each phase shifter is selected by an electronic control signal fed back to the phase shifter. An incident beam of optical energy, for example, comes from a laser, thereby being angled (ie, deflected) angularly according to a spatially varying phase shift provided by the array of the phase shifter.

Although such a device can effectively provide a relatively small angle of deflection of the incident beam (for example, ± 5 degrees), in some applications, it is still desirable to deflect the incident beam at a larger angle (for example, to a degree of ± 50 degrees).

According to the present invention, a light beam guiding system having a first plurality of volume diffraction gratings is provided. Each of the gratings is associated with a corresponding vector of the first plurality of grating vectors. The first plurality of raster vectors are substantially disposed in a first plane. Each of the gratings is configured so that the optical energy incident thereon is deflected from any one of the plurality of input directions of resonance to a corresponding one of the plurality of output directions. The system includes a second plurality of volume diffraction gratings. Each of the second plurality of volume diffraction gratings is associated with a corresponding vector of the second plurality of grating vectors. The second plurality of grating vectors are substantially disposed in a second plane different from the first plane. Each of the second plurality of gratings is configured so that the optical energy incident thereon is deflected from any one of the plurality of input directions of resonance to a corresponding one of the plurality of output directions. The invention also provides a light beam guiding device for deflecting a light beam of optical energy incident on the light beam guiding system, so that the light beam first follows the resonances of the selected gratings of the first plurality of gratings. The selected direction of the input direction is directed to the selected grating of the first plurality of gratings, and the light beam is then in the selected direction of the input directions substantially resonating with the selected grating of the second plurality of gratings Equal directions while being directed to the second plurality of gratings.

In an embodiment, the light beam guiding device is disposed in front of the first plurality of gratings and the second plurality of gratings.

In an embodiment, the first part of the light beam guiding device is disposed in front of the first plurality of gratings, and the second part of the light beam guiding device is disposed in the first plurality of gratings and the second plurality of gratings. In the meantime, the second part of the beam guiding device is shifted from the output direction from the first plurality of gratings to one of the plurality of input directions of the second plurality of gratings.

In one embodiment, the light beam guiding device includes an electro-optic light beam guiding device.

In an embodiment, the electro-optic beam director device includes an array of electronically controllable phase shifting elements for deflecting the optical energy to the first plurality of gratings inclined in the first plane, and using To deflect the first plurality of gratings inclined in the second plane.

According to an embodiment, each part of the beam guiding system includes an array of electronically steerable phase shifting elements for deflecting the optical energy incident thereon, wherein the first part of the first part of the electro-optic beam guiding device The deflection angle system is located in a first plane of deflection, and the deflection angle system for the second part of the electro-optic beam guiding device is located in a second plane, the second plane is inclined with the first plane system.

According to the present invention, a beam guiding system having a first electro-optic beam guide is provided. The first electro-optic beam guide includes a first array of electronically-controllable phase shift elements for directing an incident beam to a selected angle of a plurality of first angles in a first plane. Each of the first angles is selected according to a first electronic command fed back to the phase shift element of the first electro-optic beam director. The system includes a first grating group, which has a grating material for blocking the light beams guided by the first electro-optic light beam guide, and is used for deflecting the guided light beams at an angle of the first angles. Each of the corresponding deflected beam directions is substantially confined to the first plane. The system includes a second electro-optic beam director having a second array of electronically-controllable phase shift elements for deflecting a beam guided by the first grating group at a selected angle of a plurality of second angles. The deflection system is located in a second plane different from the first plane. Each of the second angles is selected in accordance with a second electronic command of a phase shift element fed back to the second electro-optic beam director. The system includes a second grating group, which has a grating material to block the light beam guided by the second electro-optic beam guide, and is used to deflect the guided light beam to an angle of the second angles to Corresponding directions of the plurality of second beam directions. Each of the second plurality of deflections is substantially limited to a second plane, and the second plane is different from the first plane. In one embodiment, the second plane is perpendicular to the first plane.

In one embodiment, the grating materials of the first and second grating groups are photothermally refracting glass.

Some preferred embodiments of the present invention will be described in detail as follows. Other features, objects, and advantages of the present invention will be described in detail below and will be more clearly described with accompanying drawings, wherein in all drawings, the same reference numerals indicate the same or similar elements.

Referring now to FIG. 1, the beam guiding system 10 shown in the figure includes a first electro-optic beam guide 12 (here, an optical phase array OPA), which includes a first array of electronically controllable phase shifting elements. For directing an incident light beam 14 (here, the input laser beam) to a selected angle of a plurality of first angles placed on a common plane (here, an azimuth plane). Each angle is selected according to a first electronic command of a phase shift element fed back to the first electro-optic beam director 12 via the bus 16. Here, the electro-optic beam guide is a guide of the type described in the aforementioned US patent, which guides the light beam to an azimuth direction or an angle in the azimuth plane.

A first plurality of volume diffraction gratings 18 are provided. Here, for convenience, the first plurality of volume diffraction gratings 18 are sometimes referred to as a first grating group 18. Therefore, the first grating group 18 has an internal structure which is preferably a full-image formation, which includes one or more volume Bragg gratings (hereinafter sometimes referred to as gratings). The volume Bragg grating is a dielectric or magnetic susceptibility that varies with space and is affected within the volume of the first grating group. The change in magnetic susceptibility is usually in the form of a sinusoidal dependence on the position: the plane of the material with increased susceptibility is sandwiched between the planes of the materials with reduced susceptibility. This grating is conveniently specified by its grating vector, which is a three-component vector pointing in the vertical direction of a plane composed of a volume Bragg grating, and its magnitude is inversely proportional to the sine curve change of the magnetic susceptibility. Each volume Bragg grating within the first grating group has a diffraction grating vector, and all such vectors within the first element lie substantially in a single plane. This system is a known characteristic of volume Bragg gratings: light waves traveling in a particular direction will resonate with the grating (and are therefore strongly diffracted by the grating), and the strongly resonating direction system is located at or adjacent to the sectors in those directions (Here referred to as the input space of the grating), which is located approximately in a plane perpendicular to the grating vector. This is also a known characteristic: the direction of light wave diffraction entry is related to the input direction and the grating vector, and the output direction group forms a fan shape that is roughly in a plane that is also perpendicular to the grating vector. Reference is made here to U.S. Published Patent No. 6,586,141, which was published on July 1, 2003. The inventor is Efimov et al., And the invention name is "Process for production of high efficiency volume diffractive elements in photo-thermo-refractive glass". Before the deflection from a unit vector parallel to the direction of propagation of the deflected beam, the beam deflection caused by diffraction from a grating is at Raster vector along this raster.

Each of the plurality of gratings of the first grating group 18 is associated with a corresponding vector of the plurality of first grating vectors. The plurality of first grating systems of the first grating group 18 are substantially placed in a first plane (here, the azimuth plane). Each grating deflects the optical energy incident thereon, which is from a corresponding direction of a plurality of input directions of resonance to a corresponding output direction. It should be noted that for each raster the plural input directions are the "input space" of the raster.

Therefore, the first grating group 18 has a grating material for blocking the light beams guided by the first electro-optic beam guide 12, and the group 18 divides such guided light beams in one of the first plural directions. Once deflected, each of these directions is substantially confined to the first single plane (here, the azimuth plane). Here, the first grating group 18 has an azimuth grating, and deflects a light beam incident thereon in an azimuth direction (or plane).

A second electro-optic beam guide 20 is provided, which includes a second array of electronically controllable phase shift elements (here, the optical phase array OPA), so that the light beam guided by the first grating group is divided into a plurality of first One of the two angles is selected to be deflected, and each deflection of such a second deflection located in the second plane is preferably perpendicular to the first plane, that is, the elevation plane here. The angle is selected in accordance with a second electronic command of the phase shift element fed back to the second electro-optic beam director 20 via the bus 22. Here, the electro-optic beam guide is a guide of the type described in the aforementioned US patent, which deflects the light beam at an angle in an elevation direction.

A second plurality of volume diffraction gratings 24 are provided. Here, for convenience, the second plurality of volume diffraction gratings 24 are sometimes referred to as a second grating group 24. The second grating group 24 is similar to the first grating group 18, except that all the volume Bragg gratings of the second grating group 24 have grating vectors arranged substantially on a single plane (not the same as the first plane). This plane is here an elevation plane, and the second raster group 24 may have a raster vector whose magnitude is different from that of the raster vector of the first raster group 18. Each grating of the second grating group 24 deflects the optical energy incident thereon, which is from a corresponding direction of a plurality of resonance input directions to a corresponding output direction. As mentioned earlier, for each raster the input directions are the "input space" of the raster. The input space of the gratings of the second grating group 24 is a series of trajectories that are substantially planar in an angular space.

Therefore, the second grating group 24 has a grating material for blocking the light beams guided by the second electro-optic beam guide 22, and the group 24 divides such directed light beams in one of a plurality of second directions. Upon deflection, each of the second deflection directions is substantially confined to a second single plane (this second plane is perpendicular to the first plane). Here, the second grating group 24 has an elevation angle grating and deflects a light beam incident thereon in the elevation angle direction.

In particular, the first electro-optic beam guide 12 directs the incident light beam 14 toward the first grating group 18 in a direction that is a direction selected to resonate with one of the first plurality of gratings of the first grating group 18. The second electro-optic beam guide 20 guides the light beam guided by the first grating group 18 toward the second grating group 24 in a direction, and the direction is selected from one of the second plurality of gratings of the second grating group 24. Direction of grating resonance. Here, the grating materials of the first and second grating groups are photothermal refractive glass.

Therefore, it is assumed that the incident light beam 14 is along the optical axis of the system 10, and an electronic command signal fed back to the first electro-optic beam guide 12 guides the light beam in a selected direction along a plurality of angular directions; One of a plurality of angles from the optical axis and within the elevation plane, within ± 5 degrees. This angle is selected so that the light beam leaving the first electro-optic beam guide 12 will be guided along a direction that is resonant with the volume grating of the first grating group 18, so that the first grating group 18 will generate an output beam, The output beam has a wavefront along a first predetermined angular direction. The first predetermined angular direction may be larger than ± 5 degrees from the propagation direction of the incident wavefront. It should be noted that when the final output direction is intended to be at a small angle (in this example, less than ± 5 degrees from the optical axis), the input direction selected by the first electro-optic beam director will therefore be Out of resonance with all gratings, thereby allowing the incident beam to pass through all gratings without deflection.

Next, the second electro-optic beam guide 22 guides the output beam from the first grating group 18 to within ± 5 degrees. This angle is selected so that the light beam leaving the second electro-optic beam guide 22 will have a wavefront that follows a direction that is resonant with the volume grating of the second grating group 24, so that the second grating group 24 will produce a An output beam having a wavefront along a second predetermined angular direction. The second predetermined angular direction is greater than ± 5 degrees from the propagation direction of the incident wavefront. Here, FIG. 1 shows the output beam from the system 10, which is adopted to be deflected by ± 45 degrees from the optical axis.

To understand the effects of the volume gratings 22, 24, consider the wave vector k₁Light. The wave vector of a plane wave is clearly defined to be similar to the grating vector of a grating: it is a vector perpendicular to the plane phases of the plane wave, and has a magnitude equal to the planes with a given The inverse relationship of the interval of a fixed and fixed phase distance. This phase distance can be regarded as a complete wave or a radian of phase change, or other quantities that can be easily calculated, but it is a fixed value in a given calculation method. Let the light travel in a medium, and the medium has a modulated relative dielectric conductivity: ε_r= Ε_m+ Ε_gcos (k_g.r) (1) The subscripts "m" and "g" refer to the medium and the grating, respectively. This modulation results in a wave vector k₂= K₁± k_gGeneration of upper space sidebands. If one of these sidebands resonates with a possible transmitted wave (that is, has the same wave vector and time frequency), it will excite the wave and all the energy in the original wave (assuming some design criteria are met) Will be transmitted (diffracted) to a new wave. Since the grating is static, the frequency of these sidebands is the same as that of the original light, and therefore if | k₂| = | K₁|, Then the sideband can only radiate. This is a short description of Bragg scattering from a volume grating, which is the main physical phenomenon underlying this disclosure. It should be noted that in this patent application, the term "an input wave resonates with a grating" can be understood as equivalent to "one of the two sidebands generated by this wave appears in this grating To excite this output transmission wave, "as described earlier.

Figures 2A to 2C show the geometry used for the two examples. Input and output vector k₁, K₂It has the same length and therefore must form an equilateral triangle with a raster vector as the base, which lies in any plane containing the raster vector. In Figure 2A, the wave vector is k_aIs selected to lie in the XZ plane; in Figure 2B, the wave vector is k_b, Is selected to lie in the XY plane. In Figure 2C, it shows possible wave vectors in k-space; the input and output vectors lie on a concentric circle (on the so-called Ewald Ewald sphere), which lie on two planes separated by a grating vector. These two examples are located on a sphere as shown, and in fact the two gratings can be blocked by writing to the same material. If transmitted in light along the X axis (directed directly at the viewer in Figure 2C), it will not resonate with any grating and will pass without deflection. If it is at point a₁When pointing upwards slightly downward, it will then resonate with the "a" grating and will deflect upwards to direction a₂. It should be noted that not only point a₁, Any point on the same circle will also resonate with the "a" grating. For example, with direction a₃Pointed light will resonate with the same grating and will again be deflected directly upwards to direction a₄. Otherwise, if the incident light is at point b in the -Y direction instead₁When tilted slightly upwards, it will then resonate with the "b" grating and will deflect upwards to direction b₂。

The grating extends a distance T, which is the thickness written on the plate. This results in a finite angular range of resonance conditions: the input wave vector must lie within the directional zone of the center above one of the circles in Figure 2C. This is called the "input space" of the raster. The angular width δ of this zone is roughly given as sinδ = nλ / Tsinθ, where λ is the wavelength, n is the refractive index of the material in which the grating is located, and θ is the deflection angle of scattering (outside the grating material). For example, at a wavelength of 1.5 μm and a thickness of 2 mm, a grating material with a refractive index n = 1.5, and a beam deflection angle θ of 5 ° results in an input space with a band of approximately 0.7 °; A beam deflection angle θ of 50 ° results in an input space with a zone of about 0.07 ° wide.

The non-zero width δ of the input space is the result of the finite width of the grating material, which gives the corresponding uncertainty or "fuzziness" of the grating vector. This uncertainty is only in the component of the grating vector that is orthogonal to the surface of the grating material. For simplicity, it is assumed to be a plane parallel plate. In this analysis, the grating plate is regarded as a plate extending indefinitely in the lateral direction, and the incident wave is taken as a plane wave, which is also idealized to extend infinitely in the lateral direction. These assumptions are common assumptions used in the analysis of electromagnetic wave propagation problems. With these assumptions, the exact formula for the scattering conditions is as follows: The diffraction must meet the lateral boundary condition u × (k₁+ K_g-K₂) = 0 (2) where u is a vector orthogonal to the plate and the operand is the outer product of the vector. This equation provides the vector (k₁+ K_g-K₂The second restriction condition on); the third restriction condition is not a strict restriction condition, it is the existence of the component of a full Fourier transform from a grating with a small range of values parallel to u, and Due to the limited thickness of the grating as previously described. When the input wave vector k₁When performed on the input space, the output wave vector k₂The system is located in an output space, which is a zone with a width approximately equal to δ. Note that for a given k₁, And k₂The value of is fixed; in other words, a given wave has no blurring or widening by scattering, but a change in the effectiveness of the scattering (100% at the center of the zone).

Referring again to FIG. 1, the first electro-optic beam guide 12, the first grating group 18, the second electro-optic beam guide 22, and the second grating group 24 provide a secondary or "tandem" section selector 21. "Segment" refers to the range of output angles accessible from the "area entry" subsystem 23, which is concentrated in one of the separation directions obtained from the tandem grating segment selector. In the first stage, the first electro-optic beam director 12 deflects the input beam into the input space of a selected grating of about 18 gratings (in this example) in the first grating group 18, and all the beams Deflects different amounts in the same direction (sometimes positive, sometimes negative). This causes a light to be deflected to one of the fan shapes located in a direction up to 45 ° from the incident direction. For this example, the sector with an interval of 5 ° is located at the equator of the sphere in Figures 3A, 3C, and 3B. For the sake of clarity, the scattering vectors and the input and output spaces of only two gratings are shown in Figures 3A to 3C; in Figures 3A and 3C, these gratings are azimuth deflection gratings, while in Figure 3B they are Elevation deflection grating. The incident wave system is assumed to be guided along the X axis, which is represented by a point on the center in FIGS. 3A to 3C, and it is deflected to a point by the electro-optic beam guide 12, for example: point 1 Or 5, where the input space of one of the gratings crosses the equator. Then, they are scattered to the corresponding points 2 or 6 (or other points corresponding to the remaining gratings, which are not shown in the figure for simplicity), as shown by the cross-shaped mark in FIG. 3A. Next, the second electro-optic beam director 22 deflects the wave to place it in the input space of any one of the selected gratings of the second grating of the second grating group 24, which is pointed to be perpendicular to the first grating by A fan-shaped direction deflects the light by various amounts. One such possible deflection is from 2 to 3 as shown in Figure 3A. If the system is intended to be finally completed with light in direction 4 in Fig. 3B, this method will be selectable. In this example, the rays entering the second grating group 24 will be located in the input space of the grating c of the grating group 24, and will be deflected upward to the direction 4.

In the example where the first electro-optic beam director 12 deflects the beam to point 5 (instead of point 1), the second electro-optic beam director 22 will be commanded to deflect the light from 6 up to 7, That is, once entering the second grating group (its operation is shown in FIG. 3B), it will resonate with the grating d and deflect from the direction 7 upward to the direction 8.

The other two possibilities, which are not shown, will now be described. Suppose that the second electro-optic beam guide operates on the light wave at point 2 and deflects it downward by a small amount so as to be located on the input space of the grating d (not the grating c) (in FIG. 3B ), Then it will be deflected upwards by a smaller amount, and will be located in a different section than before. Otherwise, if the upward deflection from point 6 to point 7 is replaced by the deflection of different commands in the electro-optic beam guide 22 to place the light wave in the input space of the grating c of the grating group 2, then the light wave The resulting upward deflection will be large, and it will end on the input space of the grating c of the grating group 2, which is the same as the output space of point 4 in FIG. 3B. Therefore, each output space of the second grating group is used in multiple sections, and the selected section is also determined according to the deflection that occurs in the first grating group.

In this example, the section selector 21 described here deflects a light beam to, for example, the direction 4 shown in FIG. 3B, as described below.

.Generating input waves along the X axis; Actuating the first electro-optic beam guide 12 to deflect the light to direction 1, thereby selecting a grating from the first group, which diffracts the light to direction 2; and then. The second electro-optic beam guide 22 is actuated to deflect the beam downward to a point 3 (where the point 3 is located in the input space of the grating c in FIG. 3B), which performs this operation by diffracting the beam to 4.

It should be noted that the second electro-optic beam director 22 selects the second grating and compensates for curvatures of various input spaces (as can be seen in the figure).

Referring now to FIG. 4, a beam guidance system 10 is provided<i>'</i>. Here, in this embodiment, the electro-optic light beam guiding device (that is, the first electro-optical light beam guide 12 and the second electro-optical light beam guide 22) is disposed in a plurality of first gratings 18 and a second complex number. In front of each grating 24, the exploded view of the region selection section 21 and the region entry section 23 is shown in FIG. 4A.

In this example, before the first grating group has the ability to deflect light waves at an azimuth angle and an elevation angle, the electro-optic beam guiding device is installed. Therefore, a beam guiding system 10 having a first plurality of volume diffraction gratings 18 is provided.<i>'</i>Each of the gratings is associated with a corresponding vector of the first plurality of grating vectors. The first plurality of raster vectors 18 are placed in a first plane, here is an azimuth plane. Each of the gratings deflects the optical energy incident thereon, which is deflected from a corresponding input direction of resonance to a corresponding output direction. A second plurality of volume diffraction gratings 24 are provided. Each of the second plurality of volume diffraction gratings 24 is associated with a corresponding vector of the second plurality of grating vectors. The second plurality of grating vectors are substantially disposed in a second plane different from the first plane, and here are elevation planes. Each grating of the second plurality of gratings 24 deflects the optical energy incident thereon, which is deflected from a corresponding input direction of resonance to a corresponding output direction. The system includes a beam guiding device 12, 22 for A beam of optical energy is induced to a selected grating of the first plurality of gratings 18, which is along a corresponding input direction to the resonance of a selected grating of the first plurality of gratings 18, which direction is selected to The output direction provided from the first plurality of gratings 18 is substantially equal to the input direction of the resonance of a selected grating for the second plurality of gratings 24. In other words, in this device, it is not necessary to have a part of the electro-optical beam guiding device between the two grating mechanisms. The operation of this device can be understood with reference to Figures 3C and 3B.

Consider leading to direction 4 as shown previously in Figure 3B. This requires that the light enters the second grating group along direction 3. In order to achieve this, as described above, along the X axis (as shown in FIG. 3C), light waves incident on the electro-optic beam guiding device are started. The electro-optic beam guiding device deflects the light to a direction 1 (at an elevation angle) and to a direction 2 (at an azimuth angle). These two deflections do not need to be along the elevation and azimuth angles, but only the direction of the two-dimensional range is selectable, which results in an outgoing wave in direction 2. This wave will resonate with the grating a of the first grating group and will be deflected by the grating to direction 3. Due to the previous deflection at an elevation angle, this direction is not on the equator of the sphere. Instead, its direction is selected by the elevation deflection to be located in the input space of the selected grating (here, the grating c of the grating group) from the second grating group. Therefore, it is deflected to the desired final direction 4, as shown in FIG. 3B. The other is a different setting for the electro-optic beam-guiding device, which is selected to cause the final output wave in direction 8, as shown in Figure 3B. In this example, the electro-optic beam guiding device is selected to be deflected from the X-axis to direction 5 and then to direction 6 in FIG. 3C. This places a wave that is resonant with the grating b of the first grating group, which results in a deflection to the direction 7. This wave is then placed in advance so that when it enters the grating group 2, it already resonates with the grating d.

For placement in another manner, each raster system in the first raster group 18 is associated with a corresponding vector of a plurality of first raster vectors. The first plurality of raster vectors are substantially placed in a first plane. Each of the gratings in the first grating group 18 is configured so that the optical energy incident thereon is deflected from any one of the plurality of input directions of resonance to a corresponding one of the plurality of output directions. The system includes a second plurality of volume diffraction gratings, that is, a second grating group 24. Each of the second plurality of volume diffraction gratings is associated with a corresponding vector of the second plurality of grating vectors. The second plurality of grating vectors are substantially disposed in a second plane different from the first plane. Each grating in the second plurality of gratings (ie, the second grating group 24) is configured so that the optical energy incident thereon is deflected from any one of the plurality of input directions of resonance into the plurality of output directions. One corresponding direction. A light beam guiding device is also provided for guiding a light beam of optical energy to a selected grating of the first plurality of gratings (ie, the first grating group 18), which is along the first gratings (also That is, one selected direction of the plurality of input directions of the resonance of the selected gratings of the first grating group 18), and the selected direction of the input directions of the resonances are selected to provide the signals from the first plurality of gratings (ie, the first A corresponding direction among a plurality of output directions of a grating group 18) is substantially equal to a selected direction among a plurality of input directions of the resonance of a selected grating of the second plurality of gratings (ie, the second grating group 24).

Referring again to FIG. 1 or FIG. 4, the output beam from the segment selector 21 is fed back to the segment entry segment 23. Following an elevation angle electro-optic beam guide 32, it has a series of azimuth electro-optic beam guidanceDevice 30. 30.

Some embodiments of the invention have been described above. For example, the aforementioned first and second planes need not be perpendicular to each other. Therefore, any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the appended patent application.

<p>10<i>'</i>. . .Beam guidance system</p><p>10. . .Beam guidance system</p><p>12. . .First electro-optic beam director</p><p>14. . .Incident beam</p><p>16. . .Bus</p><p>18. . .First grating group</p><p>20. . .Second electro-optic beam director</p><p>twenty one. . .Section selection section</p><p>twenty two. . .Second electro-optic beam director</p><p>twenty three. . .Segment entry segment</p><p>twenty four. . .Second grating group</p><p>30. . .Azimuth electro-optic beam guide</p><p>32. . .Elevation electro-optic guide</p>

Many aspects of the present invention can be more clearly understood with reference to the following drawings. The related drawings are not drawn to scale, and their function is only to clearly show the relevant theorem of the present invention. In addition, numbers are used to indicate corresponding parts in the drawings.

Fig. 1 is a schematic diagram of a beam guiding system according to the present invention; 2A to 2C are vector diagrams, which are helpful for understanding the beam guides of Figs. 1 and 4, and 3A to 3C are vector diagrams, which It is helpful to understand the beam directors of FIGS. 1 and 4; and FIGS. 4 and 4A are schematic diagrams of a beam guiding system according to another embodiment of the present invention. Similar numbers in the drawings indicate the same elements in all the figures .