Mobile phased grating scanner

Abstract

A scanner (100) comprises at least: a support (102), the support comprising at least one first movable part (110), an actuator, the actuator being configured to move the first movable part (110) of the support (102), and a phase-controlled grating (116), the phase-controlled grating being arranged on the first movable part (110) of the support (102) and comprising at least a plurality of optical phase shifters (122) and a light source (118) coupled to the plurality of optical phase shifters (122), the phase-controlled grating being capable of emitting a light beam from the light source (118).

Description

Technical Field

[0001] The present invention relates to a scanner or microscanner, i.e. a device capable of emitting light waves and thereby scanning a surface or a volume, and to a method for producing such a scanner or microscanner. The present invention can be used in one of the following fields:

[0002] - 2D (two-dimensional) or 3D (three-dimensional) optical scanner;

[0003] - 3D imaging, e.g. for scanning a scene with an imager for reconstruction in 3D;

[0004] - Image projection, for example in a microprojector (small projector) or producing an intraretinal projection;

[0005] - Endoscopy;

[0006] -Light detection and ranging (LIDAR), for example for self-driving cars or other areas. Background Art

[0007] A 2D optical microscanner is a device that is able to scan a scene using a light beam, thereby scanning space in two dimensions, ie scanning a surface.

[0008] Such a 2D optical microscanner is made, for example, of one or more micromirrors.

[0009] The first 2D micro-scanner with a micro-mirror architecture includes the use of two micro-mirrors. Each of the two micro-mirrors enables the incident light beam to be directed parallel to the scanning direction, and the two scanning directions of the two micro-mirrors are perpendicular to each other. The first micro-mirror of the two micro-mirrors receives a light beam from a light source and reflects the light beam in the direction of the second micro-mirror of the two micro-mirrors. The first micro-mirror is set to move so that the light beam reflected by the first micro-mirror optically scans the reflective surface of the second micro-mirror, and so that the light beam reflected by the second micro-mirror is also set to move, and the scene can be scanned according to the plane defined by the two scanning directions. However, since the two micro-mirrors need to be aligned relative to each other for managing the reflection of the incident light beam on the mirror, this micro-scanner is not compact and difficult to manufacture. In addition, the size of the second micro-mirror must be large enough. Heating problems may also occur in this micro-scanner.

[0010] A second architecture of 2D microscanners with micromirrors consists in using a single mirror capable of moving about two axes perpendicular to each other, which makes it possible to reflect an incident beam by scanning it in two perpendicular directions. However, this type of microscanner raises mechanical crosstalk problems caused by imperfections in the decoupling arms of the actuators used to set the micromirror motion. Actuation along one axis usually generates parasitic movement along another axis, since the two axes are never completely decoupled.

[0011] It is also possible to produce a 2D optical microscanner with an OPA (optical phased array), also called a phased optical emitter or phased grating. Such a microscanner comprises a plurality of beam sources, which usually come from the same initial source, which emits a main beam, which is divided into a plurality of sub-beams, for example by means of a waveguide. The sub-beams are then phase-shifted relative to each other, so that during their emission a light wave is generated, the emission angle of the light wave of the sub-beam relative to the surface from which the light wave is emitted can be adjusted by adjusting the phase shift value between each sub-beam. This operating principle can be extrapolated to a 2D array of light sources, allowing the light beam to be scanned in two directions perpendicular to each other.

[0012] An OPA can be generated by a light source operating in transmission (such as, for example, the output of a light guide or the output of a light source operating in a curved manner), in which case the phase of each light source is controlled by the position of a micromirror that is part of an array of micromirrors.

[0013] For many applications, a 2D optical microscanner needs to scan the space with a first so-called "slow" axis and a second so-called "fast" axis, which may exceed a scanning angle of 100° in both directions. For example, the target frequency for projection applications is 60 Hz for the slow axis (corresponding to the video refresh rate) and 40 kHz for the fast axis in order to obtain HD1080 resolution. For LIDAR applications, the frequency linked to the slow and fast axes is defined by the number of points per frame, which depends on the size of the object to be detected at a given distance (for example, the frequency linked to the slow axis is equal to 10 Hz, while the frequency linked to the fast axis is equal to 1 kHz).

[0014] MEMS actuators for the movement of the micromirrors enable optical scanning angles of about 100° to be achieved, however, for this purpose, these MEMS actuators generally have to be operated at a mechanical resonance frequency in order to maximize the amplitude of the movement of the micromirrors. However, due to the stiffness of the materials used (e.g., that of silicon) and the small size of the materials, the mechanical resonance frequency of the MEMS actuators is rarely less than 1 kHz and is often at least equal to at least 10 kHz. Therefore, it is difficult to produce a movement along the slow axis. Summary of the invention

[0015] An object of the invention is to propose a scanner or microscanner which does not have the disadvantages of the prior art devices disclosed above and which is suitable for scanning in one, two or three dimensions, wherein the emission angle in each dimension has a considerable value.

[0016] To this end, the present invention proposes a scanner, which at least includes:

[0017] - a support comprising at least one first movable part,

[0018] - an actuator configured to move the first movable part of the support, and

[0019] - a phased grating arranged on the first movable part of the support and comprising at least a plurality of grating phase shifters and a light source coupled to the plurality of optical phase shifters, the phased grating being able to emit a light beam from the light source.

[0020] This scanner cleverly combines a phased grating with a movable part moved by an actuator, making it possible to scan the light beam emitted from the optical phase shifter in one, two or even three dimensions. This scanner thus makes it possible to combine a scan obtained by a first movable part arranged to move the support with a scan obtained by a phase shift produced by the phased grating.

[0021] Compared to scanners that require alignment of two micromirrors, this scanner is more compact and easier to manufacture. Contrary to scanners that use a single micromirror that must be moved along two axes, the proposed scanner does not cause crosstalk problems. In addition, the production of this scanner does not require managing the flatness of the mirrors or depositing reflective materials on the mirrors.

[0022] The scanner also does not cause problems associated with movement according to a slow axis, since if scanning is to be performed according to both a fast and a slow axis, these movements of the beam can be provided by a phased grating.

[0023] The scanner advantageously corresponds to a microscanner, ie a scanner comprising elements of micrometer or nanometer dimensions. The microscanner may correspond to a component of MEMS or NEMS type.

[0024] The actuator may be of MEMS or NEMS type.

[0025] The actuator may be configured to rotationally move the first movable part of the support about at least one first axis of rotation. The movement facilitates scanning of the light beam emitted from the optical phase shifter according to a first dimension, ie parallel to the first scanning direction.

[0026] In this context and in all the rest of the text, the expression "scanning direction" is used to designate a plurality of parallel axes between and along which light waves can be emitted.

[0027] The scanner enables:

[0028] - the support comprises a fixed part and a beam, the beam comprising a first portion and a second portion, the first portion of the beam being integral with the fixed part of the support and the second portion of the beam forming a first movable part of the support, and

[0029] The actuator is configured to bend the second portion of the beam about the first axis of rotation and / or to deform the second portion of the beam in such a way as to twist the second portion of the beam about the first axis of rotation (parallel to the length of the beam).

[0030] Thus, the rotational movement of the first movable part of the support about the first rotation axis is obtained by bending and / or twisting the beam.

[0031] Alternatively, the scanner may enable:

[0032] the support further comprises at least two first arms, the first movable part of the support being suspended by the two first arms, the two first arms being aligned parallel to the first axis of rotation, the two first arms comprising first ends coupled to two opposite sides of the first movable part of the support, and

[0033] The actuator comprises two first parts, each of which is configured to deform in such a way as to cause one of the two first arms to twist and / or bend.

[0034] Thus, in this configuration, the rotational movement of the first movable part of the support about the first rotational axis is obtained by twisting and / or bending the two first arms.

[0035] In this case, the scanner can make:

[0036] - the support further comprises a second arm and a second movable part suspended by the second arm, the second arm being aligned in parallel with a second axis of rotation perpendicular to the first axis of rotation, the two first arms comprising a second end opposite to the first end and the second end being coupled to the second movable part, the second arm comprising a first end and a second end, the first end being coupled to two opposite sides comprised by the second movable part of the support, the second end being coupled to a fixed part comprised by the support, and

[0037] The actuator comprises two second parts, each second part being configured to deform in such a way as to cause one of the two second rods to twist and / or bend.

[0038] In this configuration, movement of the second movable member facilitates scanning of the light beam emitted from the optical phase shifter along a second dimension (ie, parallel to a second scanning direction that is perpendicular to the first dimension).

[0039] The first movable part of the support may comprise a face on which a phased grating is arranged, the first arm and the second arm being alignable in two directions parallel to said face of the first movable part of the support.

[0040] The plurality of optical phase shifters may be aligned parallel to or perpendicular to the first axis of rotation.

[0041] When the optical phase shifters are aligned parallel to the first axis of rotation, the optical phase shifters facilitate scanning of a light beam emitted from the optical phase shifters along a second dimension that is perpendicular to the first dimension.

[0042] When the optical phase shifters are aligned perpendicular to the first rotational axis, the optical phase shifters facilitate scanning of a light beam emitted from the optical phase shifters along a first dimension.

[0043] Alternatively, multiple optical phase shifters can be arranged by forming an array of multiple rows and columns of optical phase shifters. Such an array of optical phase shifters can help scan the light beam along two dimensions, which may or may not correspond to one or more dimensions used to set the movable part of the support into motion. Such an array can also be used to achieve more complex optical functions (focusing, diffraction, etc.). Phased gratings can be used to generate functions other than 2D scanning of light beams, such as, for example, forming diffractive optical elements, such as dynamic virtual lenses for light beam focusing or segmentation. The phased grating can also be used to generate holograms in real time.

[0044] The actuator may comprise means for actuation of at least one of the following types: electrostatic, magnetic, piezoelectric, thermal. Other types of actuation means are also possible.

[0045] The actuator may comprise one or more separate components, each component comprising a portion of piezoelectric material arranged between two electrodes. This configuration is particularly advantageous because each component of the actuator may be integrated directly on the movable component or on one of the movable components.

[0046] The plurality of optical phase shifters may include a diffraction grating coupled to a thermal phase shift device or a piezoelectric phase shift device. The light beam is emitted from the diffraction grating.

[0047] Optical phase shifters can generate light waves through constructive or destructive interference.

[0048] The invention also relates to a method for producing a scanner, the method comprising at least the following steps:

[0049] - producing a phased grating on a first part of the support, the phased grating comprising at least a plurality of optical phase shifters and a light source coupled to the plurality of optical phase shifters, the phased grating being able to emit a light beam from the light source;

[0050] - producing an actuator configured to move the first part of the support;

[0051] - Etching the support so that the first part of the support is movable.

[0052] Phased grating production can include:

[0053] - depositing a first coating layer on the support;

[0054] - depositing a core layer on the first cladding layer;

[0055] - etching the core layer to form a diffraction grating;

[0056] - Depositing a second cladding layer over the diffraction grating and the first cladding layer.

[0057] "Clad layer" refers to a layer of material suitable for forming a waveguide and diffraction grating cladding. "Core layer" refers to a layer of material suitable for forming a waveguide and diffraction grating core.

[0058] Production actuators can include:

[0059] - depositing a first conductive layer on the second SiO2 layer;

[0060] - depositing or transferring a layer of piezoelectric material onto the first conductive layer;

[0061] - depositing a second conductive layer on the piezoelectric material layer;

[0062] - etching the second conductive layer, the piezoelectric material layer and the first conductive layer in sequence, thereby forming at least a portion of the piezoelectric material disposed between the two electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The invention will be better understood when reading the description of the embodiments given for information purposes only and with reference to the accompanying drawings, in which:

[0064] - Figures 1 to 3 A scanner according to the object of the invention is shown according to several embodiments;

[0065] - Figures 4 to 15 The steps of a method for producing a scanner according to the object of the invention according to an embodiment are shown.

[0066] Identical, similar or equivalent parts in different figures described below have the same reference signs to facilitate switching from one figure to another.

[0067] The various parts shown in the drawings are not necessarily shown to the same scale in order to make the drawings easier to read.

[0068] The various possibilities (alternatives and embodiments) have to be understood as not being mutually exclusive and as being combinable. DETAILED DESCRIPTION

[0069] In the following about Figure 1 The scanner 100 according to the first embodiment will be described.

[0070] The scanner 100 includes a support 102. The support 102 is made of a substrate including, for example, a semiconductor such as silicon.

[0071] The support 102 forms a fixed, ie non-movable, part 104 .

[0072] In this first embodiment, the support 102 comprises a beam 106, a first portion 108 of which is integral with a fixed part 104 of the support 102. A second portion 110 of the beam 106 is not arranged on the fixed part 104 and forms a movable part of the support 102 which can be arranged to move relative to the fixed part 104. Figure 1 In FIG. 1 , the two parts 108 , 110 of the beam 106 are symbolically separated by a dashed line.

[0073] The scanner 100 also comprises an actuator 112 configured to move a movable part of the support 102. The actuator 112 is, for example, of the electrostatic, magnetic, piezoelectric or thermal type. Figure 1 In the example shown in , the actuator 112 is of the piezoelectric type and comprises a portion of piezoelectric material arranged between two electrodes.

[0074] The actuator 112 is arranged on the beam 106 and here at least partially covers the first portion 108 of the beam 106 and a portion of the second portion 110. The actuator 112 is thus configured to move a movable part, formed by the second portion 110 of the beam 106, relative to a fixed part of the support 102. In this first embodiment, this movement corresponds to a bending of the second portion 110 of the beam 106 about the axis of rotation 114. Thus, by applying a non-zero voltage to the electrodes of the actuator 112, the actuator can move the second portion 110 of the beam 106 rotationally about the axis of rotation 114 by means of a bimetallic effect.

[0075] exist Figure 1 In the example shown in FIG. 1 , the larger dimension of the beam 106, i.e., its length (parallel to Figure 1 The X-axis dimension visible in FIG. 1 is perpendicular to the rotation axis 114 (which is parallel to Figure 1 The length of the beam 106 is, for example, between 1 μm and several millimeters, or between 1 μm and 9 mm. The thickness of the beam 106 (parallel to Figure 1 The size of the axis Z visible in the image is, for example, between 100 nm and several tens of micrometers, or between 100 nm and 99 μm.

[0076] The scanner 100 further comprises a phased grating 116. The grating 116 is arranged on a movable part of the support 102, namely on the second part 110 of the beam 106. The grating 116 comprises a light source 118 coupled to a plurality of waveguides 120, which split a main beam from the light source 118 into a plurality of secondary beams. The light source 118 is, for example, of the LASER type, and the wavelength of the light emitted by the light source 118 depends in particular on the target application of the scanner 100. For example, for LIDAR applications, the wavelength of the light emitted by the light source 118 may be between 905 nm and 1550 nm for eye safety reasons. Each waveguide 120 is coupled to at least one optical phase shifter 122, which applies a phase shift to the received secondary beam. Each optical phase shifter 122 comprises, for example, a diffraction grating coupled to a device for phase shifting, which enables a phase shift to be applied to the secondary beam received by the optical phase shifter 122. In the first embodiment described herein, the optical phase shifters 122 are aligned adjacent to each other on the second portion 110 of the beam 106 and parallel to the axis of rotation 114. The phase shifting means ( Figure 1 ) corresponds, for example, to a piezoelectric actuator or a heating device.

[0077] Details for producing such a grating 116 are described, for example, in the paper “Silicon optical phased grating with efficient beam forming over 180 degree field of view” by CT Phare et al., published in Applied Physical Optics 2018.

[0078] Due to the bending of the beam 106 about the rotation axis 114 generated by the actuator 112, the light waves emitted by the grating 116 can be guided along a first scanning direction perpendicular to the surface of the beam 106, and the grating 116 is positioned on the surface of the beam 106 by forming an angle φ relative to an axis parallel to the length of the beam 106 when it is stationary (i.e. when not bent by the actuator 112), and the angle φ can vary, for example, between about -20° and +20°, or even between larger values ​​(such as, for example, between about -90° and +90°).

[0079] In addition, the phased grating 116 enables the emission of a beam forming a light wave along a second scanning direction parallel to the rotation axis 114 and therefore perpendicular to the first scanning direction. Thus, the light wave emitted by the grating 116 can be directed according to the second scanning direction by forming an angle θ relative to an axis parallel to the length of the beam 106, which angle θ can vary, for example, between about -80° and +80°. For example, when the grating 116 includes 64 optical phase shifters with integrated phase shifting thermal devices, the angle θ obtained can reach 160° (-80° to +80° relative to the axis parallel to the length of the beam 106).

[0080] By way of example, when the beam 106 has a thickness equal to 2 μm, the amplitude of the oscillations obtained at the end of the beam 106 where the grating 116 is located may be between 10 nm and several hundred microns, or between 10 nm and 900 μm, depending on the length of the beam 106 .

[0081] In the first embodiment described above, the first scanning direction obtained due to the phase shift of the light waves emitted by the phase-controlled grating 116 is perpendicular to the second scanning direction obtained due to setting the movable part of the support 102 in motion. The light waves emitted by the scanner 100 can then scan a surface whose limits are defined by the maximum value of the angle θ and the angle φ.

[0082] The following is about Figure 2 A scanner 100 according to the second embodiment will be described.

[0083] The scanner 100 according to this second embodiment comprises a support 102 and an actuator 112 similar to those described above for the first embodiment.

[0084] The scanner 100 according to this second embodiment comprises a phased light beam 116 disposed on a second portion 110 of the beam 106. The grating 116 comprises a light source 118 coupled to optical phase shifters 122 aligned adjacent to each other on the second portion 110 of the beam 106. As in the first embodiment, the optical phase shifters 122 comprise, for example, a diffraction grating coupled to a piezoelectric phase shifting device or a thermal phase shifting device.

[0085] In contrast to the first embodiment, the optical phase shifter 122 is aligned perpendicularly to the rotation axis 114 here. Thus, the phased grating 116 enables the emission of light waves along a first scanning direction. Thus, the light waves emitted by the grating 116 can be directed along this first scanning direction by forming an angle θ relative to an axis parallel to the length of the beam 106 not bent by the actuator 112, the angle θ being able to vary, for example, between about -20° and +20°, or even between larger values, such as, for example, between about -90° and +90°. This deviation of the angle θ of the light waves is added to the angle φ provided by the bending of the beam 106 around the rotation axis 114 caused by the actuator 112. Thus, the light waves can be emitted along the first scanning direction by forming an angle of −(θ+φ)° to +(θ+φ)° relative to the axis parallel to the length of the beam 106 not bent by the actuator 112.

[0086] In the two embodiments described above, the second portion 110 of the beam 106 is arranged to move by bending. Alternatively, the actuator 112 is capable of deforming the second portion 110 of the beam 106 in a twisting manner around an axis of the beam 106 parallel to the length of the beam 106. This twisting movement makes it possible to obtain a rotational movement of the second portion 110 around the axis of the beam 106 and thus a scan different from the scan described above. This deformation in a twisting manner of the second portion 110 of the beam 106 can be combined with or without a bending movement of the second portion 110 of the beam 106.

[0087] The following is about Figure 3 (which corresponds to a top view of the scanner 100) The scanner 100 according to the third embodiment is described.

[0088] The scanner 100 comprises a support 102 which is different from the supports described above for the first and second embodiments. The support 102 here comprises a first movable part 124 suspended by two first arms 126 which are aligned in parallel with a first axis of rotation 128 of the first movable part 124. Figure 3 , the first axis of rotation 128 is parallel to the axis Y. The first end of the arm 126 is coupled to two opposite sides of the first movable part 124. The second end of the arm 126 is coupled to a second movable part 130 of the support 102. The second movable part 130 is suspended from the fixed part 132 of the support 102 by a second arm 134, which is aligned in a manner parallel to a second axis of rotation 136 that is perpendicular to the first axis of rotation 128. Figure 3 , the second rotation axis 136 is parallel to the axis X. A first end of the second arm 134 is coupled to two opposite sides of the second movable member 130 , and a second end of the second arm 134 is coupled to the fixed member 132 .

[0089] The first arm 126 and the second arm 134 are aligned along two directions (X-axis and Y-axis) parallel to the face 138 of the first movable part 124, and the phase-controlled grating 140 is arranged on the face 138 of the first movable part 124. The grating 140 includes a light source 118 coupled to a waveguide 120, which divides a main beam from the light source 118 into a plurality of secondary beams. Each waveguide 120 is coupled to a plurality of optical phase shifters 122, which are similar to the optical phase shifters described above for the first and second embodiments, for example. In the third embodiment described herein, the optical phase shifters 122 are arranged by forming an array of optical phase shifters 122 in a plurality of rows and columns.

[0090] In this third embodiment, the actuator 112 comprises a plurality of separate components. Figure 3 1, 112.2, 112.3 and 112.4, each of which is arranged on one of the first arm 126 and the second arm 134. Each of these components 112.1-112.4 comprises, for example, a portion of piezoelectric material, arranged between two electrodes and enabling deformation in the manner of a torsion arm on which this component of the actuator 112 is arranged. Thus, due to the torsion of the first arm 126, the components 112.1 and 112.2 of the actuator 112 enable the first movable part 124 to be moved rotationally around the first axis of rotation 128, and due to the torsion of the second arm 134, the components 112.3 and 112.4 of the actuator 112 enable the second movable part 130 and therefore also the first movable part 124 to be moved rotationally around the second axis of rotation 136.

[0091] Arranging the movable part 124 to rotate about the first rotation axis 128 enables the light beam emitted by the grating 140 to be directed along a first scanning direction parallel to the second rotation axis 136. Arranging the movable parts 124 and 130 to rotate about the second rotation axis 136 enables the light beam emitted by the grating 140 to be directed along a second scanning direction parallel to the first rotation axis 128.

[0092] For example, when the first movable part 124 has a substantially circular shape, the radius of the first movable part 124 is, for example, between about 250 μm and 1 mm, and according to the shape and size of the first arm 126, the resonant frequency of the first movable part can be between about 1 kHz and 15 kHz. For example, by applying a voltage equal to 1 V to each part of the actuator 112, RMS The first movable part 124 with a radius equal to 500 μm, actuated at a resonance frequency of 8.707 kHz, with a voltage of 1.5 Å, makes it possible to obtain, at the edge of the first movable part 124 , a movement of amplitude equal to 4.7 μm relative to the position of the first movable part 124 at rest.

[0093] According to a first example of this third embodiment, the phased grating 140 can be used to increase the surface scanned by the light beam emitted by the grating 140. In fact, in this case, the angular deviation of the light beam obtained due to the movement of the first movable part 124 around the rotation axes 128 and 136 is combined with the angular deviation of the light beam obtained by the phase shift caused by the grating 140.

[0094] According to a second example of the third embodiment, the grating 140 can be used to achieve different functions, such as along a dimension perpendicular to the surface 138 on which the grating 140 is disposed (in Figure 3 The grating 140 can be used to focus the light beam emitted by the grating 140 at a variable distance from the surface 138. The grating 140 can be used to form a diffractive optical element, such as a dynamic virtual lens for beam focusing or splitting. The grating can also be used to generate a hologram.

[0095] As an alternative to this third embodiment, as in the previously described example, the support 102 may include a first movable part 124 suspended by two first arms 126, but the second ends of the arms 126 are directly connected to the fixed part 132. In this case, the support 102 does not include a second movable part 130 or a second arm 134. Even in the absence of the second movable part 130 and the second arm 134, the grating 140 is able to produce an angular deviation around the axis 136 due to the phase shift of the grating 140, that is, it is able to move the light beam along the second scanning direction. However, the amplitude of the movement of the light beam along the second scanning direction will be smaller than the amplitude of the movement in the example described above, because in this alternative, the movement of the movable part of the support 102 does not contribute to the movement of the light beam along the second scanning direction.

[0096] In general, for all embodiments, the actuator 112 may be of electrostatic (or capacitive), magnetic, piezoelectric, or thermal type.

[0097] Many alternative embodiments of scanner 100 are contemplated.

[0098] According to an alternative, for example, according to the first embodiment or the second embodiment, the scanner 100 described above may include a phased grating similar to the grating 140 described above for the third embodiment, i.e., an array of optical phase shifters 122 including multiple rows and columns. In this case, the grating 140 may help increase the deviation angle provided by the movement of the light beam 108 along the first scanning direction, and help deviate the light beam emitted along another scanning direction perpendicular to the first scanning direction. Alternatively, the grating 140 may be used to deviate the light beam emitted along two directions, which are perpendicular to the direction according to which the light beam 108 provides the deviation, for example, using one of the two directions to produce a focus of the light beam emitted along an axis perpendicular to the surface on which the grating 140 is located.

[0099] According to another embodiment, for example, the scanner 100 described above according to the third embodiment may include a phased grating similar to the grating 116 described above with respect to one of the first and second embodiments.

[0100] For all embodiments, the support 102 (fixed part + movable part) may also be set in motion in order to increase the probability that the light beam is oriented in the direction in which it is sent.

[0101] In various embodiments and examples described above, the movable part of the support is arranged to move rotationally around one or two rotation axes. Generally, the movable part of the support can be arranged to move by rotational movement and / or bending movement and / or translational movement.

[0102] Below about Figures 4 to 15 An example of a method for producing the scanner 100 according to one of the embodiments described above is described in detail.

[0103] The scanner 100 is made of a substrate 105 including, for example, silicon. Figure 4 In the embodiment shown in FIG. 1 , the substrate 105 comprises alignment marks 107 . The substrate 105 forms the support 102 here.

[0104] Firstly a phased grating 116 or 140 is produced on a substrate 105. In the example described here, the produced grating corresponds to the grating 116 described above in relation to the first and second embodiments.

[0105] For this purpose, a first coating layer 109 is produced or deposited on the substrate 105. The layer 109 comprises, for example, SiO2, which is obtained, for example, by oxidation of the silicon of the substrate 105 (see Figure 5 ). The dielectric material of the layer 109 is suitable for forming a cladding material of the light guide and corresponds, for example, to SiO2 or a polymer material. The layer 109 has, for example, a thickness comprised between about 500 nm and 3 μm.

[0106] Then, a waveguide core layer 111 is deposited on the layer 109. The optical index or refractive index of the material of the layer 111 is different from the optical index or refractive index of the material of the layer 109. In the embodiment described here, the material of the layer 111 is SiN. Other materials such as, for example, polysilicon can be used to produce the layer 111. The thickness of the layer 111 is, for example, between about 100 nm and 1 μm.

[0107] The layer 111 is then etched or structured in order to form, in particular, a diffraction grating of the optical phase shifter 122 and one or more waveguides 120 for transmitting one or more light beams from the light source 118 to the optical phase shifter 122 (see Figure 6 ).

[0108] Then, a second cladding layer 113 is produced to cover the etched layer 111 (see Figure 7 ). The material of layer 113 is selected such that the optical index of the material of layer 113 is different from the optical index of the material of layer 111 and is, for example, similar to the optical index of the material of layer 109. The dielectric material of layer 113 is suitable for forming a cladding material of the waveguide and corresponds, for example, to SiO2. The thickness of layer 113 is, for example, between about 500 nm and 3 μm.

[0109] Then, the actuator 112 is produced. In the production method described here, the actuator 112 is of the piezoelectric type.

[0110] A first conductive layer 115 is deposited on layer 113 (see Figure 8 ). This first conductive layer 115 is intended to form one of the electrodes of the actuator 112 or one of the electrodes of each of the different components of the actuator 112 (as was the case described above for the third embodiment). The layer 115 comprises, for example, platinum or molybdenum, the properties of which are chosen according to the piezoelectric material to be used. The thickness of the layer 115 is, for example, between about 100 nm and 200 nm.

[0111] Then, a piezoelectric material layer 117 is deposited on layer 115 (see Fig. 9 The layer 117 includes, for example, PZT, AlN, ZnO or BST (Ba 1-x Sr x The thickness of the TiO3 layer 117 is, for example, between about 500 nm and 2 μm.

[0112] Then, a second conductive layer 119 is deposited on the layer 117. This second conductive layer 119 is intended to form another electrode of the actuator 112 or another electrode of each of the multiple components of the actuator 112. The layer 119 comprises, for example, platinum or Mo or Ru. The thickness of the layer 119 is, for example, between about 100 nm and 200 nm.

[0113] The layer 119 is then etched by dry etching or wet etching so that one or more remaining portions of the layer 119 form an upper electrode of the actuator 112 or an upper electrode of each of a plurality of components of the actuator 112 .

[0114] Layer 117 is also etched by dry etching (e.g., plasma etching) so that one or more remaining portions of layer 117 form part of the piezoelectric material of actuator 112 or part of the piezoelectric material of each of a plurality of components of actuator 112 (see Fig.10 ). Layer 117 is etched so that one or more parts of layer 115 intended to form one or more lower electrodes of actuator 112 are not completely covered by one or more remaining parts of layer 117, so as to have multiple parts of layer 115 that can be electrically contacted.

[0115] Then, the layer 115 is etched by dry etching (e.g., plasma etching) so that one or more remaining portions of the layer 115 form the lower electrode of the actuator 112 or the lower electrode of each of the plurality of components of the actuator 112 (see Fig.11 ). Layer 115 is etched so that one or more features of layer 115 are not covered by one or more remaining portions of layer 117, so as to have multiple features of layer 115 that can be electrically contacted.

[0116] When the optical phase shifter 122 comprises piezoelectric phase shifting devices, these can also be produced using the steps described above for producing the actuator 112, which can correspond to piezoelectric actuators that are coupled to one another or independent of one another and that comprise a portion of piezoelectric material disposed between two electrodes, like the actuator 112. The mechanical deformations produced by actuating these piezoelectric actuators make it possible in this case to phase shift the light waves emitted by the optical phase shifter 122.

[0117] Alternatively, when the optical phase shifter 122 comprises a thermal phase shifting device, heating elements may be integrated between the waveguide 120 and the actuator 122, in which case these heating elements provide a phase shift of the light waves emitted by the optical phase shifter 122 by heating the material of the layer 111 to a desired temperature according to the desired phase shift.

[0118] Then, a passivation layer 121 is deposited by covering the layer 113 and the actuator 112. The layer 121 comprises, for example, an oxide such as SiO2, SiN or Si3N4.

[0119] Then, first openings 123 are etched through layer 121 to form access to the upper and lower electrodes of actuator 112 (see Fig.12).

[0120] One or more openings 125 are then etched through layer 121 in a manner facing optical phase shifter 122 to enable extraction of light from optical phase shifter 122 (see Fig.13 ).

[0121] Then, for example by depositing a conductive material and then by etching this material, conductive pads 127 are produced in the first openings 123. These pads 127 are electrically connected to the electrodes of the actuator 112 and allow control signals to be sent to the actuator 112 (see Fig.14 ).

[0122] The substrate 105 is then etched from the back side of the substrate to form one or more movable components of the scanner 100 (see Fig.15 ). In the example described here, etching of the substrate 105 enables the formation of a beam 106 comprising a first portion 108 and a second portion 110 .

Claims

1. A scanner (100), the scanner comprising at least: - a support (102) comprising at least one first movable part (110, 124), - an actuator (112) configured to move the first movable part (110, 124) of the support (102), and a phased grating (116, 140) arranged on the first movable part (110, 124) of the support (102) and comprising at least: a plurality of optical phase shifters (122); and a light source (118) coupled to the plurality of waveguides (120) and the plurality of optical phase shifters (122), wherein each waveguide (120) is coupled to at least one optical phase shifter (122), and The phased grating (116, 140) is capable of generating a light beam from the light source (118) through constructive interference or destructive interference.

2. The scanner (100) according to claim 1, wherein: The actuator (112) is configured to rotationally move the first movable component (110, 124) of the support (102) about at least one first rotation axis (114, 128).

3. The scanner (100) according to claim 2, wherein: - the support (102) comprises a fixed part (104) and a beam (106), the beam (106) comprising a first portion (108) and a second portion (110), the first portion (108) of the beam (106) being integral with the fixed part (104) of the support (102), and the second portion (110) of the beam (106) forming the first movable part of the support (102), and The actuator (112) is configured to bend the second portion (110) of the beam (106) about the first rotation axis (114) and / or to deform the second portion (110) of the beam (106) in such a way as to twist the second portion (110) of the beam (106) about the first rotation axis.

4. The scanner (100) according to claim 2, wherein: - the support (102) further comprises at least two first arms (126), the first movable part (124) of the support (102) being suspended by the two first arms (126), the two first arms being aligned in parallel with the first rotation axis (128), the two first arms (126) comprising first ends coupled to two opposite sides of the first movable part (124) of the support (102), and The actuator (112) comprises two first parts (112.1, 112.2), each of which is configured to deform in such a way as to cause the two first arms (126) to twist and / or bend.

5. The scanner (100) according to claim 4, wherein: - the support (102) further comprises a second arm (134) and a second movable part (130) suspended by the second arm (134), the second arm being aligned in parallel with a second rotation axis (136) perpendicular to the first rotation axis (128), the two first arms (126) comprising a second end opposite to the first end, and the second end being connected to the second movable part (130), the second arm (134) comprising a first end and a second end, the first end of the second arm being connected to two opposite sides of the support (102) included in the second movable part (130), the second end of the second arm being connected to a fixed part (132) included in the support (102), and The actuator (112) comprises two second parts (112.3, 112.4), each second part being configured to deform in such a way as to cause the two second arms (134) to twist and / or bend.

6. The scanner (100) according to claim 5, wherein: The first movable part (124) of the support member (102) includes a surface (138) on which the phased grating (140) is arranged, and the first arm (126) and the second arm (134) are aligned along two directions parallel to the surface (138) of the first movable part (124) of the support member (102).

7. The scanner (100) according to claim 2 or 3, wherein: The plurality of optical phase shifters (122) are aligned in parallel or perpendicular to the first rotation axis (114).

8. The scanner (100) according to claim 2 or 3, wherein: The plurality of optical phase shifters (122) are arranged by forming an array of optical phase shifters (122) in a plurality of rows and columns.

9. The scanner (100) according to claim 1 or 2, wherein: The actuator (112) includes a means for actuation of at least one of the following types: electrostatic, magnetic, piezoelectric, thermal.

10. The scanner (100) according to claim 1 or 2, wherein: The actuator (112) comprises one or more separate components (112.1-112.4), each component comprising a portion of piezoelectric material (117) disposed between two electrodes (115, 119).

11. The scanner (100) according to claim 1 or 2, wherein: The plurality of optical phase shifters (122) include diffraction gratings coupled to a thermal phase shifting device or a piezoelectric phase shifting device.

12. A method for producing a scanner (100), the method comprising at least the following steps: - producing a phased grating (116, 140) on a first movable part (110, 124) of a support (102), said phased grating comprising at least: a plurality of optical phase shifters (122); and a light source (118) coupled to the plurality of waveguides (120) and the plurality of optical phase shifters (122), wherein each waveguide (120) is coupled to at least one optical phase shifter (122); and Wherein, the phased grating (116, 140) is capable of generating a light beam from the light source (118) through constructive interference or destructive interference; - producing an actuator (112) configured to move said first movable part (110, 124) of said support (102); - etching the support (102) so that the first movable part (110, 124) of the support (102) is movable.

13. The method according to claim 12, wherein: Producing the phased grating (116, 140) includes: - depositing a first coating layer (109) on the support (102); - depositing a core layer (111) on said first cladding layer (109); - etching the core layer (111) to form a diffraction grating; - depositing a second cladding layer (113) on said diffraction grating and said first cladding layer (109).

14. The method according to claim 13, wherein: Producing the actuator (112) includes: - depositing a first conductive layer (115) on the second cladding layer (113); - depositing or transferring a piezoelectric material layer (117) on said first conductive layer (115); - depositing a second conductive layer (119) on the piezoelectric material layer (117); - etching the second conductive layer (119), the piezoelectric material layer (117) and the first conductive layer (115) in sequence, thereby forming at least a portion of the piezoelectric material disposed between two electrodes.

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