Optical scanning antenna and system comprising such an antenna

Abstract

The present invention relates to an optical scanning antenna (10) comprising: - a light source (12) generating a beam, - a dividing unit (14) that divides the generated beam into N sub-beams, - a control unit (16) for controlling the relative phase of the N sub-beams, - an integrated photonic circuit (11) comprising a set of extractors (34), the extractors (34) being arranged in a first two-dimensional periodic array, each extractor (34) being able to extract one respective sub-beam from a plane of the integrated photonic circuit (11), - an array of lenses (20) arranged in a second two-dimensional periodic array, the first array and second array having the same arrangement, and - a movement unit (22) allowing the first array and the second array to be moved with respect to each other.

Description

[0001] Optically scanned antenna and system comprising such an antenna

[0002] The present invention relates to an optically scanned antenna and a system comprising such a scanning antenna.

[0003] The invention lies in the field of laser beam deflection for applications of free-space optical communications, optical sensors or any other application involving laser beam scanning.

[0004] One of the problems to solve is to have a flat system in order to reduce the bulk and avoid protruding elements that would impair the efficiency of the antenna (turbulent environment, aero-optical effects degrading the signal sent).

[0005] Furthermore, in order to have sufficient range, the divergence of the laser beam requires an antenna size of several millimeters or even centimeters.

[0006] To obtain such a flat system, one known technique involves using flat optical beam-scanning antennas, which is a direct transposition of active radar antennas into integrated photonic technology. The antenna then consists of a two-dimensional array of transmitters fed by an equal number of integrated phase modulators for antenna control.

[0007] However, to avoid significant grating lobes, it is not possible to arrange the transmitters at half an optical wavelength in two dimensions. Even with a 10-micron gap, the grating lobes would be substantial, and with an antenna one centimeter in size, this would necessitate ordering 1000 x 1000 elements, which is not practical.

[0008] A second technique involves using an antenna consisting of a one-dimensional array of emitters. Each emitter is an optical waveguide with a structure that diffracts the optical beam out of the component's plane. This allows the elements to be positioned close to the optical wavelength, thus addressing large scanning angles without array lobes. Scanning in the second dimension is achieved by changing the laser wavelength, which alters the output diffraction angle of the emitters.

[0009] Nevertheless, a significant number of phase modulators still need to be ordered for scanning along the first dimension (10,000 for an antenna with a side length of one centimeter and elements spaced 1 micron apart), and the deflection by tunability of the laser imposes constraints on the laser that are not compatible with all applications. Therefore, there is a need for a flat antenna capable of deflecting a laser beam, with a centimeter-sized emission pupil, reduced grating lobes, and the simplest possible antenna control.

[0010] For this purpose, the description concerns an optically scanning antenna comprising: - a light source capable of generating a beam,

[0011] - a division unit capable of dividing the beam generated by the light source into N sub-beams,

[0012] - a control unit, the control unit being suitable for controlling the relative phase of the N sub-beams, N being an integer greater than or equal to 2,

[0013] - an integrated photonic circuit comprising a set of extractors, the extractors being arranged according to a first two-dimensional periodic lattice, each extractor being suitable for extracting a respective sub-beam from a plane of the integrated photonic circuit,

[0014] - a lens matrix in which the lenses are arranged according to a second two-dimensional periodic lattice, the first and second lattices having the same arrangement, and

[0015] - a displacement unit allowing the first network and the second network to be moved relative to each other.

[0016] According to other advantageous aspects of the invention, the antenna comprises one or more of the following features, taken individually or in any technically possible combination:

[0017] - each extractor is a flat mirror.

[0018] - each extractor is a Bragg grating also performing a focusing function out of the plane of the antenna of an extracted beam.

[0019] - the displacement unit is a unit specific to moving the second network in translation.

[0020] - The integrated photonic circuit includes the light source, the splitter unit and the control unit.

[0021] - the division unit includes a star coupler.

[0022] - the control unit includes a respective phase modulator for each sub-beam.

[0023] - a sub-beam is chosen as a reference, the control unit comprising a respective phase modulator for each other sub-beam.

[0024] - The light source is a linearly modulated and polarized laser source. - Each lens in the lens array is a biconvex lens. The description also applies to a system comprising an optically scanned antenna as previously described, the system being a laser remote sensing device or a telecommunications device.

[0025] In this description, the expression "specific to" means interchangeably "suited for", "adapted to" or "configured for".

[0026] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0027] - Figure 1 is a schematic perspective representation of an example of an optically scanned antenna, the antenna comprising a splitter unit, a control unit and a plurality of extractors,

[0028] - Figure 2 is a schematic representation of an example of division and control units,

[0029] - Figure 3 is a schematic representation of another example of division and control units,

[0030] - Figure 4 is a schematic representation of an example extractor, - Figure 5 is a schematic representation of another example extractor, - Figure 6 is a schematic representation of an example arrangement of the plurality of extractors from Figure 1.

[0031] - Figure 7 is a schematic representation of yet another example of an extractor, and

[0032] - Figure 8 is a representation of an example of the operation of the optically scanned antenna of Figure 1.

[0033] An antenna 10 is shown in Figure 1.

[0034] Antenna 10 is an optically scanned antenna.

[0035] Antenna 10 is an antenna suitable for performing two-dimensional scanning. These two dimensions are a first scanning direction X and a second scanning direction Y, the second scanning direction Y being perpendicular to the first scanning direction X.

[0036] Antenna 10 therefore performs a scan along the two scanning directions X and Y and can be seen as a network antenna.

[0037] The direction that allows us to create a direct reference frame with X and Y will be called the transverse direction Z in the following.

[0038] Antenna 10 is, moreover, a phase-controlled antenna, insofar as each scanning beam that antenna 10 emits is phase-controlled. Antenna 10 is a planar antenna extending mainly in a plane parallel to the plane formed by the X and Y scanning directions.

[0039] This compactness of the antenna 10 is achieved in particular by the presence of an integrated photonic circuit 11.

[0040] Such an integrated photonic circuit is often referred to by the acronym PIC, which refers to the corresponding English term "Photonic Integrated Circuit".

[0041] An integrated photonic circuit is a chip comprising several photonic components forming a planar photonic circuit.

[0042] In this case, the integrated photonic circuit 11 extends in the plane of the antenna 10, that is to say in a plane parallel to the plane formed by the X and Y scanning directions.

[0043] This makes it possible to obtain a compact antenna 10 which includes, as seen in Figure 1, a light source 12, a splitting unit 14, a control unit 16, an extraction unit 18, a lens matrix 20 and a displacement unit 22.

[0044] The light source 12 is suitable for generating the optical beam.

[0045] In the example described, the light source 12 makes it possible to obtain linearly polarized and modulated laser light

[0046] The light source 12 includes an optical source 24.

[0047] Optical source 24 is a laser source.

[0048] In some cases, the optical source 24 provides strong optical power.

[0049] Here, high optical power is defined as greater than or equal to 1 Watt.

[0050] Optical source 24 is a source modulated by a modulation.

[0051] For example, optical source 24 is modulated by a communication signal or a sensor waveform.

[0052] The light source 12 includes, in some cases, a modulation device suitable for introducing modulation.

[0053] According to one embodiment, the light source 12 includes an optical amplifier enabling a high optical power to be obtained from an optical source providing a lower optical power.

[0054] In yet another example, the light source 12 comprises a single-mode, unmodulated optical source and an optical system designed to couple the light from the single-mode optical source. The optical system is, for example, a polarization-maintaining optical fiber.

[0055] The light source 12 can be made in several ways.

[0056] According to a first example, the light source 12 is integrated on a photonic circuit. Depending on the case, the light source 12 is integrated on the same photonic circuit as one or more units among the division unit 14, the control unit 16 and the extraction unit 18 or on a different photonic circuit.

[0057] According to a second example, the light source 12 is a set of discrete components.

[0058] In the case of Figure 1, the light source 12 is made on a different integrated photonic circuit 25.

[0059] In addition, the light source 12 is connected to the division unit 14 by an optical system 27.

[0060] Optical system 27 here is a polarization-maintaining optical fiber.

[0061] The division unit 14 is suitable for dividing the beam generated by the light source 12 into N sub-beams.

[0062] N is an integer greater than or equal to 2.

[0063] Preferably, the number N of sub-beams is between 2 6 and 2 10 .

[0064] The division unit 14 is, in a simple implementation example, capable of generating N subbeams of the same intensity.

[0065] According to another example, the division unit 14 is suitable for introducing an apodization function on the distribution of intensity over the N subbeams.

[0066] The division unit 14 includes at least one optical coupler 26 allowing the incident beam to be separated into several beams.

[0067] Each coupler 26 is, for example, a directional coupler.

[0068] Alternatively, each coupler 26 is a Y junction or a multimode interference coupler (more often referred to by the name MMI which refers to the corresponding English name of "Multimode Interferometer").

[0069] According to a first example corresponding to Figure 2, the division unit 14 has a tree structure in which each output of each coupler 26 is connected to a coupler 26 via waveguides 28 until enabling the generation of N subbeams.

[0070] Such a structure is sometimes also referred to as a cascade structure. In this example, to obtain equal intensity of the sub-beams at the output, each coupler 26 is a coupler dividing the incident intensity in 2, i.e. a 50 / 50 coupler.

[0071] When an apodization function of the antenna 10 is desired, the coupling ratio between the two outputs of the coupler 26 is determined according to the apodization function to be achieved. In this case, the fixed-ratio coupler (50 / 50) can be replaced by a variable-ratio coupler (for example, a Mach-Zehnder interferometer). Alternatively, as shown in Figure 3, the splitting unit 14 has a star structure with a single coupler 26 having N outputs 26S.

[0072] The division unit 14 then comprises an input waveguide 30 followed by the coupler 26 and N output waveguides 31 each connected to a respective output 26S of the coupler 26.

[0073] The unit division 14 can be achieved in several ways.

[0074] According to a first example, the division unit 14 is integrated on a photonic circuit shared with one or more units among the light source 12, the control unit 16 and the extraction unit 18 or on a different photonic circuit.

[0075] In the case of Figure 1, the division unit 14 is integrated on the integrated photonic circuit 11.

[0076] In a second example, the division unit 14 is integrated onto a different photonic circuit. Such an implementation is particularly advantageous when high optical power is required, necessitating specific technologies for the photonic circuit, such as glass-guided optics, silicon nitride-based technology, or thick silicon-based technology.

[0077] Control unit 16 is a control unit for the relative phase shift of the N sub-beams.

[0078] According to the example described, the control unit 16 comprises a set of phase modulators 32.

[0079] Each phase modulator 32 is a component that allows the incident phase of each of the sub-beams to be modified.

[0080] As will become apparent from reading the description, the phase modulators 32 make it possible to compensate for phase discontinuities between the sub-pupils from the matrix 20 and to ensure a continuous angular sweep over the entire field.

[0081] The control unit 16 obtains control of the phase shifts introduced by the phase modulators 32 by controlling N-1 modulators 32 or N modulators 32.

[0082] In the embodiment where N-1 modulators 32 are controlled (case of figure 2), the control unit 16 takes as reference the phase of one of the sub-beams.

[0083] The control unit 16 can be integrated on a shared or non-shared photonic circuit. When the photonic circuit is shared, it can include one or more units from among the light source 12, the splitting unit 14 and the extraction unit 18.

[0084] In the example of Figure 1, the control unit 16 is part of the integrated photonic circuit 11. The extraction unit 18 is suitable for emitting the N subbeams obtained by the control unit 16 out of the plane of the photonic circuit in which the control unit 16 is integrated.

[0085] The extraction unit 18 comprises a set of waveguides 33 and a set of N extractors 34 made on a photonic circuit (shared or not).

[0086] In the example described, the two sets 33 and 34 are part of the same integrated photonic circuit 11.

[0087] According to the example described, each extractor 34 is identical.

[0088] Each extractor 34 is designed to extract a respective beam out of the plane along a given propagation direction, identical for each extractor 34.

[0089] Preferably, the propagation direction is a direction normal to the plane of the integrated photonic circuit 11. The propagation direction is then along the transverse direction Z.

[0090] According to another example, the direction of propagation forms an angle with the transverse direction Z. This angle is marked 6 in Figure 4.

[0091] Preferably, each extractor 34 generates an extracted beam exhibiting the same divergence as the other beams.

[0092] According to an embodiment corresponding to figure 4, each extractor 34 is a Bragg grating.

[0093] The Bragg grating diffracts the incident subbeam in the desired direction. The Bragg grating 34 is in a waveguide 36 formed by a guiding layer 38 situated between a lower layer 39 and an upper layer 40.

[0094] The lower layer 39, for example, is made of a buried oxide. Such a material is often designated by the acronym BOX, which refers to the corresponding English term "buried oxide".

[0095] The lower layer 39 is sandwiched between the guiding layer 38 and a substrate 42. The upper layer 40 is sometimes referred to by the English term "cladding", which can be translated as "sheath".

[0096] The top layer 40 is typically made of a TOX oxide, the acronym TOX referring to the English term "top oxide," which can be literally translated as "top oxide."

[0097] The optical index of the BOX oxide and the optical index of the TOX oxide are lower than the optical index of the substrate 42 and the guide layer 38 to ensure optical confinement along the vertical axis.

[0098] More specifically, the Bragg grating 34 is made in the guiding layer 38 by a structuring. In operation, a sub-beam 44 circulates in the guiding layer 38 and is diffracted by the Bragg grating along the arrow 46 in figure 4.

[0099] Advantageously, according to another embodiment as shown in Figure 5, each extractor 34 is a plane mirror.

[0100] Such a mirror is capable of reflecting the incident sub-beam in the desired direction.

[0101] According to the example in Figure 5, the mirror is a 45° mirror allowing reflection along the direction normal to the photonic circuit.

[0102] The 45° angle is measured here with respect to the normal direction to the photonic circuit in which the extraction unit 18 is integrated.

[0103] This operation is schematically illustrated in figure 5.

[0104] In this example, as before, a sub-beam 44 propagates in the waveguide 36 formed by the guiding layer 38 above the lower layer 39 (a layer with a lower refractive index than the guiding layer 38). The waveguide 36 rests on the substrate 42.

[0105] The extractor 34 corresponding to the inclined plane visible in figure 5 extracts by total internal reflection out of the scanning plane (plane formed by the X and Y scanning directions) the subbeam 44 propagating in the waveguide 36.

[0106] As can be seen in this figure 5, the beam reflected by the extractor 34 emerges in the transverse direction Z as indicated by arrow 46.

[0107] It appears from this representation that each extractor 34 is connected to an output of a respective waveguide 47 of the control unit 16 via the waveguide assembly 33, i.e. that each subbeam 44 propagates through a waveguide assembly to a respective extractor 34.

[0108] The 34 extractors are arranged according to a first network R1.

[0109] The first network R1 is a two-dimensional periodic network which is schematically represented in Figure 6.

[0110] The first network R1 presents, for example, a square mesh or a hexagonal mesh.

[0111] The period of the first network R1 is denoted P.

[0112] The period is between 0.1 mm and 1 mm.

[0113] According to a particular embodiment, the extraction unit 18 is designed to focus the output beam.

[0114] Such a focusing function is, for example, obtained by adding a lens deposited on the surface of the integrated circuit.

[0115] Alternatively, the focusing function is performed by the extractors 34. As an illustration, in the case of extractors 34 which are mirrors, the inclined plane of the mirror has a curvature which generates a focusing of the output beam.

[0116] In the case of Bragg gratings, the characteristics of each of the gratings are determined to add a focusing function which allows control of the divergence of the diffracted beam out of the plane of the integrated circuit.

[0117] An example of such an embodiment of a Bragg grating generating a focusing of an incident subbeam is illustrated in Figure 7.

[0118] The matrix 20 is a set of lenses 48 forming substantially a plane parallel to the plane formed by the X and Y scanning directions.

[0119] Furthermore, according to the example described, each lens 48 is identical.

[0120] Each lens 48 has dimensions small enough to be classified as a microlens.

[0121] A microlens is a lens with a diameter of 5 millimeters or less. The position of the matrix 20 and the curvatures of the entrance 50 and exit 52 diopters of each lens 48 are centered and determined to meet several criteria, including:

[0122] • collimate the beams at the output of matrix 20,

[0123] • ensure a good level of extinction of the array lobes of the antenna 10, and • ensure that the center of gravity of the beam is maintained at the center of the output diopter of the matrix 20 during a displacement of the matrix 20 relative to the extraction unit 18.

[0124] According to one embodiment, each lens 48 has an entrance diopter and an exit diopter, each having a curved shape.

[0125] Preferably, each 48 lens is a biconvex lens.

[0126] The curvature of the entrance diopter 50 (in the direction of propagation of light, i.e. facing the extraction unit 18) then serves as a field lens to keep the light beam at the center of the output diopter 52 of the lens 48 when the latter is placed off-axis.

[0127] The curvature of the output diopter 52 is calculated so as to collimate the beam at the output of the matrix 20.

[0128] Matrix 20 is arranged according to a second R2 network.

[0129] The second network R2 is the same two-dimensional network as the first network R1.

[0130] In particular, the two arrays R1 and R2 have the same period P and the same arrangement, in particular a square or hexagonal arrangement. The matrix 20 is positioned in a plane parallel to the extraction unit 18 at a distance which depends on the divergence of the beams from the extraction unit 18 and the period P, so that the size of the sub-beams on each output diopter 52 of each lens 48 optimizes the level of the array lobes in the far field of the antenna 10.

[0131] Each lens 48 is thus arranged opposite a respective extractor 34.

[0132] In the event that the beam emitted by the extraction unit 18 has a propagation direction different from the normal to the surface of the integrated circuit, the curvature of the input diopter 50 of each lens 48 is modified to introduce an emission angle correction function. This can lead to shapes of the input diopter 50 that are not rotationally symmetrical and are not centered on the output diopter 52.

[0133] Regardless of the direction of propagation of the beam emitted by the extraction unit 18, according to a particular embodiment, each lens 48 is a diffractive lens, which makes it possible to produce lenses with a very small thickness.

[0134] Such a lens profile is obtained by etching patterns smaller than the wavelength to achieve modulation of the effective refractive index.

[0135] The displacement unit 22 allows the matrix 20 to be moved in a plane parallel to the extraction unit 18.

[0136] The displacement unit 22 therefore allows the matrix 20 to be moved along the first scanning direction X and the second scanning direction Y, the distance between the matrix 20 and the extraction unit 18 along the transverse direction Z remaining fixed.

[0137] The displacement unit 22 is suitable for achieving a displacement limited to a distance of P / 2 in each scanning direction X or Y.

[0138] The displacement unit 22 is thus suitable for carrying out a translation of one of the networks relative to the other. The displacement unit 22 is, for example, a piezoelectric unit of translational displacement.

[0139] Alternatively, the displacement unit 22 is a magnetic subunit of translational displacement.

[0140] It will be understood here that the unit of displacement 22 can be any means allowing the first network (that of the extractors) and the second network (that of the lenses 48) to be moved relative to each other.

[0141] In particular, it is possible to consider a relative displacement obtained by a partial displacement (case of two displacement subunits) or total displacement of the first network (case of a single displacement subunit at the level of the extraction unit 18).

[0142] According to a specific embodiment, the displacement unit 22 performs such a translation by modifying only the position of the second array. The antenna 10 allows, in operation, a two-dimensional optical scan to be performed.

[0143] To illustrate this possibility, it is helpful to refer to Figure 8, which illustrates a schematic diagram of beam deflection for different relative positions of the first network (that of the extractors 34) and the second network (that of the matrix 20).

[0144] According to the schematic diagram in Figure 8, the divergence 0 in the middle of index n constituting matrix 20 is:

[0145] > >

[0146]

[0147] Or :

[0148] • HAS o denotes the wavelength of the subbeams in a vacuum; e0 is the divergence of the subbeams in a vacuum, and

[0149] •

[0150]

[0151] the waist of the subbeams emitted by the extractors 34.

[0152] To minimize network lobes, we must have:

[0153]

[0154] Where D is the thickness of a lens, assumed to be attached to the extraction unit 18 to simplify calculations.

[0155] We therefore obtain the first relation:

[0156]

[0157] When the radius of curvature R of the input diopters 50 and output diopters 52 is chosen to collimate the beams exiting the matrix 20 (i.e., R=nD), the relationship between the angle <p' du rayon central d’un faisceau émis par un extracteur 34 décentré de d par rapport au centre de la matrice 20, et la direction normale à la matrice 20 s’écrit :

[0158] ,

[0159] tan <p = - d

[0160] The deflection angle p of the subbeams at the output of matrix 20 is then:

[0161] <

[0162]

[0163] We then obtain the final relation giving the deflection angle of the antenna as a function of the relative displacement d of the extraction unit 18 with respect to the matrix 20, the period P of the two gratings and the divergence of the extractors 34 in the vacuum 60:

[0164] 2d

[0165] <P « 0Q y

[0166] It is then possible to perform an order-of-magnitude calculation of the sizing and performance of antenna 10. We consider the case where we want to obtain a total transmitting surface of 1cm x 1cm. For a period P of 0.5 mm, the first grating is a 20x20 grating with 34 extractors to be controlled.

[0167] In practice, the relative displacement of the extraction unit 18 with respect to the matrix 20 can be limited to d / P~0.25 to limit the geometric aberrations of the diopters.

[0168] The available scanning angle then depends solely on the divergence of the beams emitted by the extraction unit 18.

[0169] For example, for beams of 1 pm diameter at 1 the 2 , i.e., o>0= 0.5 pm, we obtain a scan p of:

[0170] <

[0171]

[0172] >

[0173] The number of directions N dir resolved (by dimension), defined by the ratio of the scanning angle and the divergence of the composite beam is thus

[0174] 5000

[0175]

[0176] Antenna 10 thus allows a scan of 5000 directions on each dimension.

[0177] The phase-controlled optical antenna 10 is made on an integrated photonic circuit and consists of a two-dimensional periodic array of extractors 34, which can be 45° mirrors or Bragg grating couplers, with a spacing between elements much greater than the optical wavelength.

[0178] The present antenna 10 therefore combines an integrated photonic circuit comprising a two-dimensional periodic array of extractors 34 with a matrix 20 of the same period, the array and the matrix 20 being mobile relative to each other.

[0179] Lateral displacement of the lenses relative to the integrated photonic circuit creates a deflection of the transmitted laser beam and phase control of the elements allows coherent combination of subbeams in the far field.

[0180] The matrix 20 is, moreover, adapted to the divergence and spacing of the elements of the antenna 10 so as to minimize the array lobes.

[0181] Such a structure makes it possible to obtain a 10 two-dimensional optically scanned antenna that does not involve scanning the wavelength of the laser source and minimizes grating lobes without having to arrange the radiating elements at half a wavelength.

[0182] Indeed, a large scanning angle (typically more than 10° on either side of a reference direction) is achieved in two dimensions with a limited number of elements (typically 400 for a centimeter antenna with a spacing of 250 microns between elements). Compared to the prior art, this implies a reduction of several orders of magnitude in the number of phase elements to be ordered.

[0183] The present antenna 10 is thus a flat antenna allowing the deflection of a laser beam, with a centimeter emission pupil, reduced grating lobes and the simplest possible antenna control.

[0184] This is advantageous for a plurality of systems including such an antenna 10.

[0185] One such example of a system is a telecommunications device.

[0186] In particular, the 10 antenna is especially well-suited for free-space communications in the space domain (Earth-satellite), or carrier-to-carrier communications in the terrestrial, naval, air, and space domains. The 10 antenna's compact size and planar configuration (low form factor) make it potentially suitable for stealth applications and drone-to-drone communications. Furthermore, the antenna's transmission direction is largely independent of the optical wavelength, making it potentially usable for multi-wavelength optical telecommunication protocols. For example, the 10 antenna is well-suited for wavelength division multiplexing (WDM).

[0187] Another example of a possible system is a laser remote sensing device.

[0188] Such a remote sensing device is more often referred to as LIDAR, which refers to the corresponding English term "Light Detection And Ranging," literally meaning detection and estimation of distance by light.

[0189] Yet another example of a system is an FMCW system. The abbreviation FMCW refers to the corresponding English name for "Frequency-Modulated Continuous-Wave," literally meaning frequency modulation of continuous waves.

Claims

DEMANDS 1. Optically scanning antenna (10) comprising: - a light source (12) capable of generating a beam, - a division unit (14) suitable for dividing the beam generated by the light source (12) into N sub-beams, N being an integer greater than or equal to 2, - a control unit (16), the control unit (16) being suitable for controlling the relative phase of the N sub-beams, - an integrated photonic circuit (11) comprising a set of extractors (34), the extractors (34) being arranged according to a first two-dimensional periodic lattice, each extractor (34) being suitable for extracting a respective sub-beam out of a plane of the integrated photonic circuit (11) along a given propagation direction, identical for each extractor (34), - a lens matrix (20) in which the lenses are arranged according to a second two-dimensional periodic lattice, the first and second lattices having the same arrangement, and - a displacement unit (22) allowing the first network and the second network to be moved relative to each other by a translation.

2. Optically scanning antenna according to claim 1, wherein each extractor (34) is a plane mirror.

3. Optically scanned antenna according to claim 1, wherein each extractor (34) is a Bragg grating also performing an out-of-plane focusing function of the integrated photonic circuit (11) of an extracted subbeam.

4. Optically scanning antenna according to any one of claims 1 to 3, wherein the displacement unit (22) is a unit suitable for moving the second array in translation.

5. Optically scanned antenna according to any one of claims 1 to 4, wherein the integrated photonic circuit (11) comprises the light source (12), the splitter unit (14) and the control unit (16).

6. Optically scanned antenna according to any one of claims 1 to 5, wherein the splitter unit (14) comprises a star coupler.

7. Optically scanned antenna according to any one of claims 1 to 6, wherein the control unit (16) comprises a respective phase modulator for each sub-beam.

8. Optically scanned antenna according to any one of claims 1 to 7, wherein a subbeam is chosen as a reference, the control unit (16) comprising a respective phase modulator for each other subbeam.

9. Optically scanning antenna according to any one of claims 1 to 8, wherein the light source (12) is a linearly modulated and polarized laser source.

10. Optically scanning antenna according to any one of claims 1 to 9, wherein each lens of the lens array (20) is a biconvex lens.

11. System comprising an optically scanning antenna (10) according to any one of claims 1 to 10, the system being a laser remote sensing device or a telecommunications device.

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