Adaptive optical device with simplified structure and related manufacturing method

Abstract

The present invention relates to an adaptive optical device (I) comprising a deformable plate (2) intended to deform an incident wavefront by refraction and / or reflection, characterized in that it comprises tabs (5) fixedly attached to the plate (2) and a frame (21) fixed relative to the plate (2), each tab (5) comprising a moving part (22) connected to at least one respective peripheral actuator (7) so that the at least one respective peripheral actuator (7) can locally deform the tab (5) in order to transmit a deformation force to the deformable plate (2), and each tab (5) further comprising a respective fixed part (23) fixedly attached to the frame (21) so that it is immobilized relative to the frame. The present invention is particularly suitable for the introduction or controlled correction of optical aberrations in the incident wavefront.

Description

[Technical Field]

[0001] The present invention relates to the general technical field of adaptive optics for various applications such as astronomy, medicine, etc., and in particular to uses in opthalmology, lasers, microscopy, microelectronics, etc.

[0002] More specifically, the present invention relates to adaptive optical devices that include a deformable plate intended to deform an incident wavefront by refraction and / or reflection.

[0003] The present invention also relates to a method for manufacturing such an adaptive optical device.

[0004] prior art It is known to use active, i.e., adaptive, optical devices, such as deformable mirrors, that allow for the creation or correction of optical aberrations, such as astigmatism, in an incident wavefront in a controlled manner. In practice, such deformable mirrors can change their configuration to modify the shape of the incident wavefront as desired, due to a deformation imposed on the surface of such mirror, where the incident wavefront is reflected. The incident wavefront reaching the surface of the mirror is transformed into a reflected wavefront, and the initial optical aberrations (aberrations of the incident wavefront) are created or corrected by the deformable mirror. Specifically, there are known adaptive mirrors in the field of astronomy that comprise a circular deformable plate containing a reflective surface, which is connected to and surrounded by a rigid and thick ring, the latter being extended outward by a number of arms. Each arm is connected to a pair of actuators intended to apply a force or pair of forces to the periphery of the ring in order to deform the plate and thus the wavefront reflected on the reflective surface of the plate. To achieve sufficient deformation and reduce the risk of deforming the plate, the latter also has a significant thickness with a specific and thick central pupil.

[0005] Although they are generally satisfactory in their intended field of application (astronomy), these known adaptive mirrors still have some drawbacks.

[0006] Indeed, these known mirror designs require the implementation of a large number of actuators, especially since each arm must be equipped with a pair of actuators to achieve the desired deformation amplitude. Then, since the ring is relatively stiff and thick, and the plate also has a relatively large thickness, the actuators must be sized accordingly so that they exert sufficient torque through the ring on the edge of the plate to deform it, making the entire system relatively heavy. Finally, the arm itself must be stiff and thick so that it can withstand the force exerted by its associated actuator pair. Furthermore, current configurations of deformable mirrors with arms require the use of a large number of arms, and therefore a large number of actuators, to deform the plate as desired.

[0007] These different requirements and constraints therefore increase manufacturing costs, result in significant size and weight, as well as significant inertia (or response time) to deformation and particularly difficult mounting and setup of these known mirrors.

[0008] Furthermore, during manufacture, each pair of actuators must be positioned in a very precise manner not only relative to their respective arms, but also relative to each other. Even more complex, multiple pairs of actuators must be positioned in a particularly accurate and precise manner relative to each other.

[0009] These last two constraints increase the manufacturing costs of these known mirrors even more, and the proper setting of the actuator pairs becomes particularly complicated in practice.

[0010] Thus, in these known mirrors, by their mere design, there is a significant risk of improper positioning of some actuators, which increases the risk of inaccuracies in the control of the deformation of the reflective surface of the plate, reflected by imperfections in the correction or desired introduction of optical aberrations in the incident wavefront, thus affecting the reliability of these known mirrors.

[0011] Consequently, the aforementioned known mirrors are relatively bulky, heavy and expensive, and are not characterized by optimal reliability and responsiveness. Summary of the Invention

[0012] The object assigned to the present invention is therefore intended to overcome the different drawbacks mentioned above and to provide a new adaptive optical device that is robust, compact, light, has controlled manufacturing costs, is easy and is quick to implement.

[0013] Another object assigned to the present invention is intended to provide a new adaptive optical device with a simple and reliable structure.

[0014] Another object assigned to the present invention is intended to provide a new adaptive optics device that, by design, allows for easy, fast and inexpensive setup within an optical system.

[0015] Another object assigned to the present invention is to provide a new adaptive optical device, adapted to generate a desired curvature (concave or convex) of its deformable plate in a particularly simple, reliable and controlled manner, for example to deform an incident wavefront in a controlled, precise and rapid manner.

[0016] Another object assigned to the present invention is to provide a new adaptive optics device that is particularly easy to implement for introducing or correcting optical aberrations by reflection and / or refraction, and at the same time easy and quick to service and set up.

[0017] Finally, another object assigned to the present invention is to provide a new adaptive optical device that has a very simplified and light structure, but makes it possible to obtain a wide range of deformation amplitudes in a precise and controlled manner.

[0018] Furthermore, another object assigned to the present invention is to provide a new method for manufacturing adaptive optical devices that is easy, fast and cheap to implement, while making it possible to obtain adaptive optical devices that are particularly reliable, compact, responsive, light and robust.

[0019] The object assigned to the present invention is an adaptive optical device comprising a deformable plate intended to deform an incident wavefront by refraction and / or reflection, said device comprising at least: a leg fixedly attached to the deformable plate; a frame fixed relative to the deformable plate; a plurality of peripheral actuators; Further provided with This is achieved using an adaptive optical device, characterized in that each leg comprises a movable part connected to at least one respective one of the peripheral actuators, each of which is capable of locally deforming the leg, the legs transmitting a deformation force to the deformable plate, and each leg further comprising a respective fixed part fixedly attached to the frame so as to be immobilized relative to the frame.

[0020] The object assigned to the present invention is also achieved using a method for manufacturing an adaptive optical device, comprising the primary step of making or preparing a deformable plate intended to deform an incident wavefront by refraction and / or reflection, said method comprising at least: a secondary step of creating legs fixedly attached to the deformable plate; an installation step, wherein a respective movable portion of each leg is connected to at least one respective actuator, the at least one respective actuator being capable of locally deforming the leg, the leg transmitting a deformation force to the deformable plate; a fastening step in which a respective fixed portion of each leg is fixedly attached to a frame fixed relative to the deformable plate so as to be immobilized relative to the deformable plate; The invention further comprises: [Brief explanation of the drawings]

[0021] Other characteristics and advantages of the invention will appear in more detail on reading the description that follows, with reference to the accompanying drawings, which are given by way of illustrative and non-limiting example only, and in which: [Figure 1] 1 shows a perspective view of a sagittal cross section of an embodiment of an adaptive optical device of the present invention, viewed from the hidden side of the plate. [Figure 2] 2 is a schematic side view of a sagittal cross section of the adaptive optical device of FIG. 1. [Figure 3] 1A shows a schematic side view of a sagittal cross section of a particular embodiment of an adaptive optical device having an obtuse dihedral angle between the deformable plate and the legs, no frame, and no actuators. [Figure 4] 10 shows a schematic side view of a sagittal cross section of another particular embodiment of an adaptive optical device having an acute dihedral angle between the deformable plate and the legs, no frame, and no actuators. [Figure 5] 13 shows a sagittal cross section of yet another embodiment of an adaptive optical device with a right dihedral angle between the deformable plate and the legs, no frame, and no actuators. [Figure 6] 10 shows a sagittal cross section of yet another embodiment of an adaptive optics device having rounded legs, no frame, no actuators, and an obtuse dihedral angle between the deformable plate and the legs. [Figure 7] 10 shows a perspective view of the plate with legs of the adaptive optical device of FIG. 9, looking at the deformable plate from its entrance side. [Figure 8] 10 shows a perspective view of the plate and legs of FIG. 9, with the deformable plate viewed from its hidden side, each leg being provided with a respective peripheral actuator herein. [Figure 9] 1 is a perspective view showing an embodiment of an adaptive optical device of the present invention; [Figure 10] 10 shows a perspective view of a first alternative manufacturing method according to the invention for producing the adaptive optical device of FIG. 9, further comprising a central actuator; [Figure 11] 10 shows in perspective view a portion of a second alternative manufacturing method according to the invention for producing the adaptive optical device of FIG. 9; [Figure 12] 1 illustrates a perspective view of one embodiment of a hexagonal deformable plate and trapezoidal legs of an adaptive optics device of the present invention, viewed from the hidden side of the plate. [Figure 13] 10 shows a perspective view of another embodiment of a deformable plate and legs of an adaptive optical device of the present invention, viewed from the hidden side of the plate. [Figure 14] 1 shows a perspective view of a particular embodiment of a deformable plate and legs according to an adaptive optical device of the present invention, as seen from the hidden side of the plate. [Figure 15] 1 shows a perspective view of an adaptive optical device according to the present invention, in which a deformable plate is deformed by an actuator to have contours of one example of a deformation mode; DETAILED DESCRIPTION OF THE INVENTION

[0022] According to a first aspect shown in the figures, the invention relates to an adaptive optical device 1 .

[0023] The adaptive optical device 1 is therefore advantageously intended to be used in systems requiring the use of adaptive optics, such as microscopy systems, astronomical observation systems, atmospheric turbulence vision correction systems, image magnification or reduction systems, zoom systems, image distortion systems or ophthalmic imaging systems.

[0024] According to the invention and as represented in the figure, the adaptive optical device 1 comprises a deformable plate 2 intended to deform an incident wavefront by refraction and / or reflection.

[0025] Preferably, the adaptive optical device 1 constitutes a deformable mirror and / or an adaptive lens. For example, the adaptive optical device 1 is intended to introduce or correct optical aberrations in an optical wavefront (or a light ray). Therefore, the adaptive optical device 1 is advantageously designed, for example, when it constitutes a deformable mirror to introduce or correct optical aberrations in the wavefront, in particular to reflect the incident wavefront dynamically, i.e., in a modifiable and controlled manner. Preferably, the adaptive optical device 1 is designed, for example, when it constitutes an adaptive lens to introduce or correct optical aberrations in the wavefront, in particular to refract the incident wavefront dynamically, i.e., in a modifiable and controlled manner. For example, the adaptive lens constitutes a refractive medium, for example, a medium more refractive than air or the lens environment, to deform the incident wavefront. For example, the deformable plate 2 forms one of the surfaces of the adaptive lens, and the adaptive lens includes at least one refractive material, in particular a fluid or solid, and even a gas, with a refractive index different from 1, in particular greater than 1. Preferably, the adaptive lens is at least partially deformable, in particular at the level of the deformable plate 2 .

[0026] Advantageously, in the absence of any external influences, the deformable plate 2 has, by its mere structure, a generally planar or curved shape. For example, the deformable plate 2 is slightly warped, i.e. convex (or slightly concave, depending on the point of view). Preferably, for the surface of the (slightly) warped deformable plate 2 to be considered as planar at least locally (i.e. over at least a portion of the surface area of ​​the deformable plate 2), the convexity (or concavity, depending on the point of view) of the deformable plate 2 is sufficiently small, i.e. has a relatively large radius of curvature compared to the dimensions of the deformable plate 2.

[0027] Preferably, and as represented in the figures, at rest the deformable plate 2 extends substantially according to a first mean plane of extent P. Thus, at rest, i.e. advantageously in the absence of any deformation mechanical load applied to the deformable plate 2, for example by an actuator, the plate is advantageously inscribed in the first mean plane of extent P (whether it is planar or slightly warped) which intersects the deformable plate 2, preferably over most, nearly all or all of its thickness.

[0028] Advantageously, the deformable plate 2 is a thin deformable plate that is deformed in particular by the action of an external force applied to its surface, in particular a force applied by at least one actuator.

[0029] Preferably, the deformable plate 2 is made from a material that is relatively flexible, but still has some mechanical strength, so that it deforms only slightly or not at all unless subjected to minimal external pressure or tension. Advantageously, the deformable plate 2 therefore has some mechanical strength and is not sagging, but is also somewhat soft and somewhat flexible enough to undergo slight elastic deformations, i.e., is reversible when subjected to bending loads, particularly by actuators (described in more detail below).

[0030] Preferably, the deformable plate 2 is made mainly of silicon, metal (e.g., steel or aluminum), alloy, polymer(s), composite(s), ceramic(s), glassy amorphous material(s) (e.g., organic or inorganic glass, such as Pyrex), quartz or its derivatives, or an assembly of different materials, in particular several of the aforementioned materials. Advantageously, the deformable plate 2 has an average thickness of substantially 5 to 500 μm. Preferably, for the intended function of the present invention, the deformable plate 2 has a relatively modest size. For example, the deformable plate 2 has a diameter (e.g., if the deformable plate 2 is circular) and / or a larger dimension (e.g., length, e.g., if the deformable plate 2 is oval or rectangular) of 5 to 300 mm.

[0031] Preferably, and as shown, the deformable plate 2 has a geometric centre C, eg a centre of mass and / or centre of gravity.

[0032] Preferably, the deformable plate 2 has a peripheral edge 11. For example, and as shown in particular in Figures 1, 7 to 11, 13, and 14, the deformable plate 2 has a substantially circular or elliptical overall shape. The peripheral edge 11 defining the deformable plate 2 therefore advantageously takes on a circular or elliptical shape in these last two embodiments. Alternatively, the deformable plate 2 has the shape of a triangle, a rectangle, a square, a trapezoid, or any other suitable geometric shape or polygon. The peripheral edge 11 therefore alternatively describes a polygon, for example a rectangle, or a hexagon, as shown in Figure 12.

[0033] According to the present invention, the deformable plate 2 has an entrance surface 3 intended to accept a wavefront. Preferably, the entrance surface 3 comprises or forms an optical surface useful for carrying out applications in adaptive optical systems, the optical surface preferably intended to accept an incident wavefront. The entrance surface 3 (more specifically, the optical surface) preferably has a substantially smooth surface intended to accept an incident wavefront, and the deformable plate 2 and / or the entrance surface 3 are designed to introduce or correct optical aberrations when the deformable plate 2 is actively deformed. Therefore, the deformable plate 2 is preferably intended to be reversibly deformed according to several deformation configurations, one of which is shown in FIG. 15. The entrance surface 3 is therefore advantageously flat (i.e., integrally made, having visual, physical, and mechanical continuity) without any unevenness or irregularities, and is preferably intended to accept an incident wavefront.

[0034] Advantageously, the deformable plate 2 is designed to accept an incident wavefront, in particular via the entrance surface 3, and to deform it in a controlled manner so as to emit a deformed (in particular reflected and / or refracted) wavefront. More particularly, the deformable plate 2 is preferably designed to accept an incident wavefront in order to: In particular, if the adaptive optical device 1 is a deformable mirror, to reflect it in the form of a reflected wavefront (with deformation), and / or In particular, if the adaptive optical device 1 is an adaptive lens, to refract it in the form of a refractive wavefront (ie to transmit it with a deformation).

[0035] For example, the reflected and / or refracted beam either has optical aberrations not present in the incident wavefront, or corrections for optical aberrations present in the incident wavefront, or both. Preferably, the reflected and / or refracted wavefront is thus modified compared to the incident wavefront. In other words, since the adaptive optical device 1 is, by definition, adaptable according to the desired modification, incident wavefront, angle of incidence of the incident wavefront, medium, etc., the adaptive optical device 1 is advantageously designed to modify the incident wavefront in a controlled manner, thereby according to several successive configurations. Optionally, the adaptive optical device can be designed to reflect one portion of the incident wavefront and refract another portion.

[0036] Advantageously, the deformable plate 2 further has a hidden surface 4 opposite the entrance surface 3. Advantageously, the entrance surface 3 and the hidden surface 4 are therefore on opposite surfaces of the deformable plate 2. The deformable plate 2 therefore advantageously has, at rest, a generally planar or alternatively curved shape, the entrance surface 3 and the hidden surface 4 being separated by a thickness of the deformable plate 2, which thickness is preferably relatively small compared to the radial extent of the surfaces 3, 4 of the deformable plate 2. According to a first alternative, the entrance surface 3 is (at least locally) substantially parallel to the hidden surface 4. According to another alternative, in some cases, in particular when the adaptive optical device 1 is an adaptive lens (or a specific deformable mirror), the entrance surface 3 is not parallel to the hidden surface 4, and the deformable plate 2 is, for example, curved on the two opposite surfaces of the deformable plate 2, i.e., in other words, substantially convex on both the entrance surface 3 and the hidden surface 4, or conversely substantially concave on both the entrance surface 3 and the hidden surface 4.

[0037] If the adaptive optical device 1 constitutes a deformable mirror, the entrance surface 3 advantageously forms a reflecting surface. Of course, if the adaptive optical device 1 constitutes an adaptive lens, incident light rays advantageously traverse the deformable plate 2 by entering the deformable plate 2 via the entrance surface 3 and exiting the deformable plate 2 via the hidden surface 4. Thus, although the thickness of the deformable plate 2 may play a role in the deformation of the incident wavefront, the hidden surface 4 is then "hidden" only from the point of view of the incident wavefront.

[0038] Advantageously, the deformable plate 2 is intended to be subjected to, for example, forces and / or pairs of compressive and / or tensile forces applied to the periphery of the deformable plate 2, more particularly to the peripheral edge 11, allowing the deformable plate 2 to be deformed reversibly (i.e. advantageously in the elastic region), in a controlled and appropriate manner, i.e. in a satisfactory manner such that the adaptive optical device 1 fulfils its function in the adaptive optical system. Preferably, the forces and / or pairs of forces are applied to the side of the hidden surface 4 and / or to the hidden surface 4, for example to generate a convex or concave surface on the opposite entrance surface 3.

[0039] Preferably, the entrance surface 3 and the hidden surface 4 are made integrally with the deformable plate 2, e.g. machined from the same material. Alternatively, the deformable plate 2 is made up of several plate parts fixed, e.g. glued, to one another, one of which comprises the entrance surface 3 (or a part of the entrance surface 3, e.g. the optical surface) and another of which comprises the hidden surface 4.

[0040] According to the invention and as shown in the figures, the adaptive optical device 1 further comprises legs 5 fixedly attached to the deformable plate 2. The legs 5 are therefore advantageously fixed to the deformable plate 2, and thereby fixed in a permanent and irreversible manner. In other words, the legs 5 are preferably in an embedded connection with the deformable plate 2. Advantageously, the legs 5 are separate from one another, i.e., preferably not directly connected to one another; the legs 5 are also advantageously separate from one another. For example, each leg 5 is in the form of a portion of a thin deformable plate that deforms and / or advantageously moves, e.g., folds, under the action of an external force applied to its surface, in particular a force applied by at least one actuator. Preferably, the legs 5 are attached directly to the deformable plate 2 without any significant intermediate elements (other than possible adhesives, weld beads, etc.), preferably without any intermediate elements that are rigid and / or have some mechanical strength.

[0041] Preferably, none of the legs 5 are directly fixed to the other legs 5, i.e., it may be possible, for example, to fold one of the legs 5 without the other legs 5 being folded or moved, or at least without them being folded or moved in the same way as the leg 5 under consideration. Preferably, the legs 5 are attached to the deformable plate 2 via a peripheral edge 11 and may be substantially elongated. Preferably, each leg 5 extends from the deformable plate 2, preferably from the peripheral edge 11, in a radial direction relative to the geometric center C, e.g., outward, as shown in particular in FIGS. 1 to 3 and 7 to 14, or inward according to another embodiment, as shown in FIG. 4. Advantageously, as shown in the figures, the legs 5 are uniformly angularly distributed around the geometric center C. As shown in the figures, all of the legs 5 are, for example, substantially identical to one another, although it may also be possible for some legs 5 to be relatively larger and / or thicker and / or stiffer and / or longer than others. According to a particular embodiment, each leg 5 preferably extends in a regular manner on either side of one (single) corresponding longitudinal axis of extent such that there are straight line segments passing through the material forming the leg 5 over the entire leg 5, as shown in the embodiments of Figures 1 to 4 and 7 to 14. Preferably, each axis of extent passes through a central axis extending substantially perpendicular to the deformable plate 2 and passing through the geometric center C.

[0042] Advantageously, as shown in the particular embodiment represented in the figures, the peripheral edge 11 is free except for its connection with the legs 5. In other words, the peripheral edge 11 is preferably not connected to any structure (other than the deformable plate 2) except for the legs 5. Such a "free" peripheral edge configuration 11 thereby makes it possible to obtain a wide variety of possible deformation amplitudes of the deformable plate 2 without applying any significant forces to the legs 5, for example using the peripheral actuators 7 described in more detail below.

[0043] Preferably, the peripheral edge 11 advantageously does not have a significant excess thickness, for example, it is no more than three times, preferably no more than two times, thicker than the rest of the deformable plate 2. In particular, the peripheral edge 11 advantageously has a thickness similar to the rest of the deformable plate 2, possibly with a tolerance of no more than 25%, more preferably no more than 15%. Preferably, as shown in the figure, each leg 5 is separated from its adjacent leg 5 by a space 6. Each leg 5 is therefore advantageously bounded by two of the spaces 6, which are separated from each other by legs 5. For example, the spaces 6 may be fairly wide, in particular as wide as the legs 5 or wider than the legs 5, or even narrower than the legs 5, as shown in the figure, and the spaces 6 are then preferably formed by grooves (or slots). The legs 5 are preferably not directly connected to each other, and the spaces 6 are advantageously open through-holes. Advantageously, the plate 2 and the legs 5 attached thereto together form an integrally deformable body in the form of a star with several branches, each branch being formed by one of the legs 2. Alternatively, the deformable plate 2 and the legs 5 together form a circular overall structure, with each leg 5 advantageously forming a respective peripheral portion of a respective circular sector of the set having the circular overall structure. Optionally, each of the legs 5 has a petal-like shape and arrangement surrounding the deformable plate 2. Advantageously, the peripheral edge 11 has free portions in the space 6, and therefore portions that are not connected to any structure (other than, of course, the deformable plate 2 and the free portions belonging to the deformable plate 2). More specifically, the free portions can partially define the space 6. In other words, advantageously, the peripheral edge 11 comprises, between each pair of adjacent legs 5, a respective free portion (as described above) that is not connected to any structure.

[0044] According to a second aspect, the present invention relates to a method for manufacturing an adaptive optical device 1. Preferably, the method is carried out to manufacture an adaptive optical device 1 as described above and below. Thus, the previous description regarding the adaptive optical device 1 as well as the following description preferably also apply to the manufacturing method according to the invention, and vice versa, and the following description regarding the manufacturing method preferably also applies to the adaptive optical device 1 according to the invention.

[0045] Thus, according to a second aspect of the invention, the manufacturing method comprises the primary step of making or providing a deformable plate 2 intended to deform an incident wavefront by refraction and / or reflection.

[0046] Further according to the present invention, the manufacturing method further comprises at least one secondary step of fabricating legs 5 fixedly attached to the deformable plate 5. For example, as shown in the figures, the adaptive optical device 1 preferably comprises at least four legs 5, in particular 4 to 20 legs 5, such as eight legs 5 as shown in Figures 7 to 10, or four legs 5 according to another embodiment as shown in Figure 13, or six legs 5 according to yet another embodiment as shown in Figures 11 and 12, or eighteen legs 5 according to yet another embodiment as shown in Figure 1, or eleven legs 5 according to yet another embodiment as shown in Figure 14. Thus, the number of legs 5 of the adaptive optical device 1 may be an even number, as shown in most of the figures, or an odd number, as shown in Figure 14.

[0047] According to a first alternative, particularly shown in Figures 1, 7 to 10 and 12 to 14, the legs 5 are made integrally with the deformable plate 2, and the primary and secondary production steps, for example, occur at least partially simultaneously, in particular comprising a common step of cutting the blank plate 12 to form the legs 5 and the deformable plate 2, as shown in Figure 10. In the last case, the peripheral edge 11 of the deformable plate 2 can be at least partially formed by an imaginary limit between the body of the plate 2 and the legs 5, in particular as represented by the dotted lines at the tips of the legs 5 in Figures 9, 12 and 13. Thus, according to this embodiment, the plate 5 is preferably made from the same blank plate 12, for example, by forming spaces 6 in the thickness of the blank plate 12 to form the legs 5, while at the same time defining a central region that advantageously does not include the spaces 6 and forms at least part of the deformable plate 2. Each leg 5 is therefore advantageously separated from the leg 5 immediately adjacent to it by a clearance (space 6) made in the thickness of the blank plate 12. Preferably, the blank plate 12 is made in one piece. According to this embodiment, the deformable plate 2 (or at least one part thereof) and / or the leg 5 are preferably formed at least partially, preferably completely, from cut-outs in the edge of the blank plate 12, as shown by the first two views of Fig. 10. One advantage of a common cutting step is that it makes it possible to form the leg 5 and the deformable plate 2 in one piece and in one single operation, thereby ensuring good and easily reproducible mechanical strength.

[0048] According to a second alternative, as specifically shown in FIG. 11 , the legs 5 are attached to the deformable plate 2, specifically during a secondary fabrication step. For example, the secondary fabrication step comprises a step of fixing the legs 5 to the deformable plate 2, for example by welding, gluing, and / or brazing. According to this alternative, the deformable plate 2, on the one hand, and the legs 5, on the other hand, are formed independently of each other. In this last case, the adaptive optical device 1 comprises a welded and / or glued interface between each leg 5 and the deformable plate 2, preferably at the level of the peripheral edge 11 of the deformable plate 2. The spaces 6 are then simply formed by attaching the legs 2 to the deformable plate 2 at a distance from each other during a secondary fabrication step. One advantage of the fixing step is that it allows the legs 5 and the deformable plate 2 to be formed separately, which is easier to manufacture separately, for example by molding, machining, or any other suitable means.

[0049] Preferably, specifically during the fixing step, at least a part (or the whole) of the legs 5 are fixed to the deformable plate 2 as follows. As shown in FIG. 11, on the edge of the deformable plate 2, for example on the peripheral edge 11, On the deformable plate 2, more particularly on the entrance face 3, the legs 5 are for example partially pre-pressed against the entrance face 3, and / or Below the deformable plate 2 , more particularly above the hidden surface 4 , the legs 5 are for example partially pre-pressed against the hidden surface 4 .

[0050] It will be appreciated that it is entirely possible, for example, for some of the legs 5 to be fixed on the edge of the deformable plate 2 while others are fixed above and / or below the deformable plate 2, and all suitable combinations are possible depending on the desired use and design of the adaptive optical device 1.

[0051] According to yet another alternative, the deformable plate 2 and the legs 5 are formed from an integrally molded set, advantageously comprising the deformable plate 2 and the legs 5 attached to the deformable plate 2 and separated from one another by spaces 6. According to another alternative, some of the legs 5 are attached to the deformable plate 2, while others of the legs 5 are made integrally with the deformable plate 2, in particular by molding and / or cutting. According to this embodiment, the primary step of making or providing the deformable plate 2 and the secondary step of making the legs 5 occur simultaneously during the step of molding the advantageously integrally molded set comprising the deformable plate 2 and the legs 5. In this last embodiment, the molded set is molded, for example with molten material, to form the deformable plate 2 with lateral legs separated from one another, the lateral legs forming the legs 5. According to yet another alternative, the deformable plate 2 is prepared during the primary step, i.e. delivered ready for use.

[0052] According to the invention, the adaptive optical device comprises a plurality of peripheral actuators 7. Further according to the invention, each leg 5 comprises a movable part 22 connected to at least one corresponding one of the peripheral actuators 7, such that the peripheral actuators 7 can locally deform the leg 5, so that the leg 5 transmits a deformation force to the deformable plate 2. The movable part 22 therefore preferably consists of a part of the leg 5 that is connected to the peripheral actuators 7 and made movable by actuation of the peripheral actuators 7. Each movable part 5 is therefore preferably connected to one of the peripheral actuators 7. More preferably, each movable part 22 is connected to a single corresponding peripheral actuator 7 among the plurality of peripheral actuators 7. Conversely, in an advantageous manner, each peripheral actuator 7 is connected to only one of the movable parts 22. Therefore, each peripheral actuator 7 is preferably connected to only one of the legs 5.

[0053] Advantageously, each peripheral actuator 7 is therefore intended to displace the movable part 22 so as to deform the deformable plate 2, the legs 5 transmitting a part of the deformation imparted by the peripheral actuator 7 to the deformable plate 2, in particular at the level of the peripheral edge 11. In other words, the adaptive-optical device 1 preferably comprises a plurality of peripheral actuators 7, each of which is connected to a corresponding one of the legs 5 and deforms it at the level of the corresponding movable part 22 of the leg 5. Advantageously, each corresponding peripheral actuator 7 is designed to exert a compressive or tensile force on the corresponding leg 5, in order to cause a local displacement and / or deformation of the leg 5, at the level of a part of this leg 5 referred to as the movable part 22. This displacement and / or this deformation results in the application of a deformation force to the deformable plate 2, in particular at the level to which the legs 5 are advantageously connected, preferably via the peripheral edge 11, in order to deform the incident wavefront when reflected on the entrance face 3 and / or refracted through the deformable plate 2. This makes it possible to at least locally deform the curvature of the deformable plate 2 (and thus advantageously the curvature of its entrance surface 3), thereby effectively deforming the deformable plate 2 to introduce or correct optical aberrations in the wavefront reflected and / or refracted by the deformable plate 2. This results in the curvature changing at least locally according to the forces applied by the peripheral actuators 7 on the legs 5. For example, each peripheral actuator 7 is arranged on the same side of the deformable plate 2, preferably on the side of the hidden surface 4, or alternatively on the side of the entrance surface 3. Preferably, all peripheral actuators 7 are on the same side of the first mean plane P. Alternatively, at least one of the peripheral actuators 7 is arranged on the side of the hidden surface 4 and at least another of the peripheral actuators 7 is arranged on the side of the entrance surface 3, so that the (two) peripheral actuators 7 are arranged on either side of the first mean plane P.Preferably, each leg 5 therefore has both sufficient flexibility to be locally deformed by the actuator 7 to which it is connected as the actuator 7 displaces the mobile part 22, and some sufficient mechanical strength to influence the shape of the deformable plate 2 by transmitting a deformation force through the peripheral edge 11. Advantageously, the peripheral actuator 7 may be of any type (piezoelectric, magnetic, two-part, mechanical, threaded, etc.), including those known in the considered technical field. For example, the peripheral actuator 7 is connected to the leg 5 through adhesive points, thereby defining the mobile part 22, and transmits a tensile or compressive force locally to the surface of the mobile part 22 to displace it and thus deform the deformable plate 2 fixed to the plate 5.

[0054] According to a first aspect of the invention, the adaptive optical device 1 further comprises a frame 21 fixed relative to the deformable plate 2. In other words, the frame 21 advantageously remains stationary when the deformable plate 2 deforms to modify the incident wavefront in a controlled manner. For example, the peripheral actuator 7 may be of a two-part magnetic type, as specifically shown in Fig. 2, where a movable part of the peripheral actuator 7 is connected to the corresponding leg 5 and a stationary part of the peripheral actuator 7 is connected to the frame 21. In general, the frame 21 can advantageously also be considered fixed relative to the peripheral actuator 7, which is movable (or at least whose active part is movable).

[0055] According to a particular embodiment, the peripheral edge 11 is not (directly) connected to the frame 21 (but indirectly via the legs 5).

[0056] For example, the frame 21 has a peripheral body having the same kind of shape as the shape of the deformable plate 2, such as a circular peripheral body when the deformable plate 2 is circular, or a rectangular peripheral body when the deformable plate 2 is rectangular, as shown in Figures 1, 2, 9, 10 and 14. For example, especially when the deformable plate 2 has a substantially circular or elliptical overall shape, the frame 21 advantageously comprises a rigid ring 8, in the center of which the deformable plate 2 with its legs 5 is arranged. In particular, the ring 8 (and more generally the peripheral body) is designed to surround the deformable plate 2 and the legs 5. For example, the ring 8 is shaped like a cylinder, for example with circular or polygonal guide curves.

[0057] The frame 21 may be integral, i.e. formed in one single block in the same way as the ring 8, as shown in most of the figures (and for the ring in particular in Figures 1, 9 and 10), or alternatively it may have a discontinuous aspect, as shown in Figure 13, wherein the frame 21 comprises, for example, arms 30 (or screws or rivets) connected to the legs 5 and arranged at a distance from each other, the arms 30 being therefore fixed with respect to the deformable plate 2 and preferably with respect to the peripheral actuator 7. Optionally, as shown in Figure 2, the frame 21 further comprises a support 31, which is connected to the ring 8, which is resting on the support 31, for example via an embedded connection. The peripheral actuator 7 (or additional actuator 29, as will be seen later) may be partially resting on the support 31 and connected thereto in translation, i.e. the active part of the peripheral actuator 7 (or additional actuator 29) is designed to be able to perform a translational movement with respect to the support 31 and more generally with respect to the frame 21.

[0058] According to the invention and as specifically shown in the figures, each leg 5 further comprises a respective fixing part 23 fixedly attached to the frame 21 so as to be immobilized relative to the frame 21. Preferably, the fixing part 23 is immobilized at least translationally according to one fastening direction F relative to the frame 21, i.e., the fixing part 23 is fastened to the frame 21 so as not to be able to perform a translational movement relative to the frame 21 at least according to the fastening direction F and therefore not to be able to move away from or approach the frame 21 at least according to the fastening direction F, as specifically shown in FIG. 2. Preferably, the fastening direction F is formed by a line perpendicular to the entrance face 3, i.e. by a line perpendicular at a point to the surface of the deformable plate 2 facing the entrance face 3. According to one embodiment, the fastening direction F is formed by a line perpendicular to a plane tangent to the entrance face 3 at a point, in particular when the deformable plate 2 is curved (but this also applies when it is flat). According to another embodiment compatible with the previous one, the fastening direction F is formed by a line perpendicular to the first mean plane of extension P, in particular when the deformable plate 2 is substantially planar (however, this also applies when it is slightly warped).

[0059] According to a first alternative, the fixed part 23 does not have any degrees of freedom relative to the frame 21, while according to other alternatives the fixed part 23 has one or several degrees of freedom relative to the frame 21.

[0060] For example, the fixed portion 23 is is in embedded connection with the frame 21 and therefore does not have any degrees of freedom relative to the frame 21, or is in pivotal connection with the frame 21 and therefore has at least one degree of freedom relative to the frame 21; or It is connected to the frame 21 by a ball joint and therefore has at least two degrees of freedom relative to the frame 21.

[0061] The fixed part 23 can also have one or two degrees of freedom of translation relative to the frame 21 according to one or two directions of free translation and thus advantageously different from the fastening direction F. The direction(s) of free translation therefore preferably do not coincide with and are non-parallel to the fastening direction F, for example perpendicular to the fastening direction F and / or perpendicular to each other.

[0062] The fixed part 23 is therefore unable to depart from the frame 21 and preferably unable to move relative to it (it is embedded) and is dependent on it. Nevertheless, as previously disclosed, the fixed part 23 is alternatively able to change its orientation relative to the frame 21 (pivot or ball-joint connection) while remaining attached to the frame 21 at a fixed point. The fixed part 23 of the leg 5 is therefore advantageously fixed at least in translation along an axis locally perpendicular to the deformable plate 2 (for example, corresponding to the fastening direction F in the embodiment shown in FIG. 2 ), the other degrees of freedom (two translations and three rotations) may or may not be fixed. In other words, the fixed part 23 is preferably immobilized in translation relative to the frame 21 at least according to the fastening direction F, but the fixed part 23 may optionally have one or two degrees of freedom in translation relative to the frame 21 and / or one, two or three degrees of freedom in rotation, according to alternative forms, or may have no degrees of freedom relative to the frame 21, i.e., be completely immobilized relative to the frame 21.

[0063] Each leg 5 therefore advantageously has a respective fixed part 23, which is rigidly connected to the frame 21 so as to be immobilized relative to it, i.e. at least translationally immobilized relative to the frame 21. Preferably, the fixed parts 23 are attached to the frame 21 in direct or almost direct contact with the frame 21. Advantageously, the fixed parts 23 do not move, in particular translationally, relative to the frame 21 to which they are advantageously fixed, regardless of the local deformation of the leg 5, or more particularly the displacement of the mobile part 22, and regardless of the deformation of the deformable plate 2. Advantageously, this makes it possible to apply a pair of forces to the surface of the deformable plate 2, on the one hand, by displacing each leg 5 by means of a respective peripheral actuator 7 connected to the leg 5 at the level of the mobile part 22, and on the other hand, by applying a "biasing force" or "holding force" to the leg 5 by its fixed part 23 to the frame 21, without any excessive force from the peripheral actuator 7, and fastening each of the fixed parts 23 of each of the legs 5 to the frame 21, ensuring control of the deformation of the deformable plate 2. The combination of the fixed part 23 and the mobile part 22 with the considered legs 5 therefore advantageously makes it possible, by lever effects and / or pairs created on the one hand by the deformation forces exerted by the peripheral actuators 7 and on the other hand by the (constant and without any calibration required) holding or biasing forces of the fixed part 23, to precisely control the amplitude of the deformation of the deformable plate 2 and at the same time rationalize the number of peripheral actuators 7 and / or their power as well as the number of legs 5. For example, the number of actuators (peripheral actuators 7 and / or additional actuators 29 described below) corresponds exactly or approximately (for example + / - 2) to the number of possible deformation modes or profiles of the deformable plate 2.

[0064] If the frame 21 is discontinuous, each of the arms 30 is fixed to a corresponding one of the legs 5 at the level of a respective fixing portion 23, as shown, for example, in Figure 13. If the frame 21 is made in one piece, the frame 21 formed, for example, by the rings 8, is fixed to the legs 5 via their respective fixing portions 23, as shown in particular in Figures 1, 9 and 10. In either case, the frame 21 is preferably not in direct contact with the deformable plate 2.

[0065] According to the present invention, the manufacturing method comprises at least an installation step, in which the respective movable part 22 of each leg 5 is connected to at least one respective actuator 7, which is capable of locally deforming the leg 5, so that the leg 5 transmits a deformation force to the deformable plate 2; a fastening step in which the respective fixed portion 23 of each leg 2 is fixedly attached to a frame 21 fixed relative to the deformable plate 22 so as to be immobilized relative to the deformable plate 22; Further includes:

[0066] In other words, during the mounting step, each peripheral actuator 7 is advantageously fastened to a respective leg 5, for example by gluing, welding, brazing or any other suitable fastening means. In Figures 3 to 6, each peripheral actuator 7 not shown in these figures may for example be located below the corresponding leg 5.

[0067] Preferably, in particular during the mounting step, the peripheral actuators 7 are not directly connected to the deformable plate 2, in particular to the peripheral edge 11 of the deformable plate 2. On the contrary, the peripheral actuators 7 are advantageously arranged to act on the deformable plate 2 only indirectly via the plate 5, in particular to deform the deformable plate 2 as well as the entrance surface 3. They are therefore preferably separate from the peripheral actuators 7. Although the use of the legs 5 in the adaptive-optical device 1 of the present invention allows for greater precision in the deformation of the deformable plate 2 and thus for improved precision in correcting or introducing optical aberrations in the entrance wavefront, it does not, as such, preclude the use of additional actuators 29 directly connected to the peripheral edge 11 of the deformable plate 2.

[0068] For example, during the fastening step, the legs 5 are riveted, screwed, glued, brazed, and / or welded to the frame 21. According to this embodiment, during the fastening step, a portion of each leg 5 is attached to the frame 21, for example with at least one rivet, at least one screw, adhesive, welding, brazing, or any other suitable attachment means, so as to form the fixed portion 23 of the corresponding leg 5. Preferably, the mounting step also includes connecting a portion of each peripheral actuator 7 (and further of each additional actuator 29, including the central actuator 27 described below) to the frame 21, for example via a portion of the peripheral actuator 7, for example by gluing, screwing, riveting, clipping, welding, or brazing.

[0069] According to another embodiment, the manufacturing method further comprises a second step of cutting the blank plate 12 to form the frame 21 or at least one part of the frame 21, the second cutting step then advantageously occurring at least partly simultaneously with the common cutting step, whereby the frame 21 is advantageously integral with the legs 5 (and the deformable plate 2) and formed substantially simultaneously with these from the blank plate 12. Alternatively, the manufacturing method comprises the step of providing a frame 21 ready for installation.

[0070] For each considered one of the legs 5, the fixing portion 23 can comprise, for example, a surface portion fastened to the frame 2 of the leg 5. According to another embodiment, the fixing portion 23 can be essentially point-like, i.e. specifically attached to the frame 21 very locally during the fastening step and specifically via one or several fastening points, each formed, for example, by a screw or a rivet.

[0071] Advantageously, during the installation step, each leg 5 is preferably connected to only one corresponding peripheral actuator 7. More specifically, during the installation step, each movable part 22 is preferably connected to only one corresponding peripheral actuator 7. Thus, one single peripheral actuator 7 per leg 5 is advantageously sufficient to displace the legs 5 and generate sufficient twisting at the periphery of the deformable plate 2, for example, to use the adaptive optical device 1 in an adaptive optical system. Preferably, the design of the adaptive optical device 1 according to the invention allows for only one single peripheral actuator 7 per actuator 5, and the combination of the movable part 22 and the fixed part 23 allows each leg 5 to actuate at least one deformation mode of the deformable plate 2 (and thus of the wavefront) with a wide variety of amplitudes, streamlining the number of legs as well as the number of actuators and / or their power and / or their sizing compared to prior art configurations, thereby facilitating the setup and use of the adaptive optical device 1 according to the invention and thereby facilitating the manufacturing method. The implementation of the adaptive optical device 1 is particularly simple. This is because the fixed parts 23 represent the "passive" parts of the legs 5 (possibly in translation, since rotation is still possible) that need only be fastened to the frame 21, while the movable parts 22 represent the only "active" parts of the legs 5. Naturally, the fixed parts 23 are preferably not directly connected to the actuators 7, advantageously since they are not movable in translation relative to the frame 21. This clever configuration therefore makes it possible to limit the manufacturing costs and complexity of the adaptive optical device 1 of the invention compared to prior art configurations. Alternatively, each leg 5 is connected to several peripheral actuators 7 that are simple to set up and operate, for implementation with sufficient precision, thanks to the retention ensured by the fixed parts 23.According to this last alternative, during the installation step, each leg 5 is connected to several corresponding peripheral actuators 7, for example two peripheral actuators 7, which are arranged at a distance from each other and each connected to a different movable part 22 of the leg 5, as shown in FIG. 14 . This last alternative has some of the same advantages as before, namely a wide variety of possible deformation amplitudes of the deformable plate 2, as well as peripheral actuators 7 with precisely sized power, while having a large number of possible deformation profiles. As before, it is also possible that some of the legs 5 are connected to one single peripheral actuator 7, while others of the legs are connected to several peripheral actuators 7, as before. Naturally, the manufacturing method advantageously includes a step of providing or manufacturing the peripheral actuators 7.

[0072] According to one embodiment, all of the fixed parts 23 are immobile relative to one another, especially in the case of embedded frame 21 / fixed part 23 connections.

[0073] According to a particular embodiment, the respective peripheral actuators 7 of two different corresponding legs 5 are designed to be coupled and actuated according to one another in order to deform the deformable plate 2 in a controlled manner, for example by applying a torque to the deformable plate 2, preferably via its peripheral edges 11. Furthermore, the torque does not need to be particularly high, and the fixed parts 23, and in particular the lever effect induced by the fixed parts 23, make it possible to advantageously control the deformation precisely and without any considerable force.

[0074] Preferably, the legs 5 are soft in order to be able to deform locally at the level of the movable part 22 when the respective peripheral actuator 7 to which they are connected displaces and / or deforms its movable part 22, for example by pushing or pulling it. The legs 5 are therefore advantageously flexible enough to fold elastically when subjected to a tensile or compressive force by the respective peripheral actuator 7, but rigid or resilient enough to recover their original shape and position when the peripheral actuator 7 no longer applies any force; this feature of the legs 5 is reinforced by the presence of the fixed parts 23 (which exert a force to "bias" or "hold" the legs 5). Such a configuration is particularly advantageous for easily and accurately calibrating the adaptive optical device 1 while ensuring good operating times for the adaptive optical device 1.

[0075] Advantageously, the adaptive optical device 1 of the present invention allows for the implementation of a deformable and thin or very thin deformable plate 2, where the expected force from the peripheral actuators 7 to deform the deformable plate 2 in an effective and controlled manner is significantly reduced compared to prior art adaptive optical devices. Advantageously, such a configuration therefore allows for the use of peripheral actuators with limited power (and therefore cost), which, in combination with a streamlined number of peripheral actuators 7 (because fixed portions 23 are attached to frame 21 rather than to the actuators) and a thin deformable plate 2, allows for a significant reduction in size and weight of the adaptive optical device 1, for a result that is at least as effective as prior art adaptive optical devices implementing more complex designs with more and / or more powerful actuators.

[0076] Advantageously, as shown in the figures, each leg 5 extends between a respective proximal end 24 attached to the plate 2 and a respective distal end 25 opposite the proximal end 24. Preferably, the distal end 25 is the part or end of the leg 5 considered that is furthest from the deformable plate 2, and the proximal end 24 is preferably the part or end of the leg 5 considered that is closest to the deformable plate 2.

[0077] According to an alternative, the fixed portion 23 is located closer to the distal end 25 than to the proximal end 24. According to a particular embodiment of this alternative, as specifically shown in Figures 1, 2, 9, and 10, the fixed portion 23 comprises a distal end 25, which is therefore fixedly attached to the frame 21. For example, as shown in Figure 1, the fixed portion 23 comprises only the distal end 25 of the corresponding leg 5, which is preferably attached to the frame 21 (or more specifically, to the ring 8, as shown in Figure 1) via only the distal end 25, such as by riveting, screwing, gluing, welding, brazing, or the like. According to another embodiment, as specifically shown in FIGS. 2 , 9 and 10 , the rigid ring 8 has an inner shoulder 26 to which the legs 2 are fastened, and the fixing portion 23 advantageously comprises, in addition to the distal end 25, a portion of the surface of the corresponding leg 5, which surface portion is attached (for example, riveted, screwed, glued, brazed or welded) to the ring 8, or more generally to the frame 21, for example, at the level of the shoulder 26. For example, the inner shoulder 26 may be formed by a bore formed through the thickness of the ring 8, allowing easy placement of the deformable plate 2 with the legs 5, which abut against the inner shoulder 26 via the respective fixing portion 23. According to an alternative, the fixing portion 23 may be located between the distal end 25 and the proximal end 24, the distal end 25 possibly being free, i.e. not connected to the frame 21. According to a particular embodiment not shown here, the fixing portion 23 is located closer to the proximal end 24 than to the distal end 25. According to yet another particular embodiment not shown here, the fixing portion 23 is located equidistant between the proximal end 24 and the distal end 25 .

[0078] Preferably, the mobile part 22 is arranged between the distal end 25 and the proximal end 24, as shown in the figure. The mobile part 22 is preferably formed by a portion of the corresponding leg 5 at the level to which the corresponding peripheral actuator 7 is associated, for example via an adhesive point as described above. Alternatively, the mobile part 22 may be arranged at least partially at the level of the distal end 25 and / or at the level of the proximal end 24.

[0079] According to a particular embodiment, the movable part 22 is arranged closer to the proximal end 24 than to the distal end 25, as shown in Figures 8 to 10 and 13. In other words, according to this example, the movable part 22 as well as the peripheral actuator 7 are arranged closer to the deformable plate 2 than to the distal end 25. This configuration is advantageous, for example, when the fixed part 23 includes the distal end 25, since this makes it possible to set the fixed part 23 and the movable part 22 at a distance from each other, in particular, while bringing the movable part 22 close to the deformable plate 2, thereby allowing a substantial deformation of the deformable plate 2, while thereby applying relatively low stresses to the legs 5 when the corresponding peripheral actuator 7 is operating, without the peripheral actuator 7 having to exert a substantial force.

[0080] Alternatively, the mobile part 22 is arranged equidistant between the proximal end 24 and the distal end 25. Naturally, the advantage of this last configuration lies in its simple construction, but may also result from other parameters (shape of the legs 5, desired deformation of the deformable plate 2, etc.).

[0081] According to yet another alternative, the movable part 22 is positioned closer to the distal end 25 than to the proximal end 24. This last configuration may be advantageous in some cases, for example, when the legs 5 have a particular shape (e.g., a trapezoid, as described below) that is more likely to deform towards the distal end 25 than towards the proximal end 24, as in FIG. 12 , and / or when the adaptive optical device 1 is relatively bulky and / or the legs 5 are very short, as in FIG. 1 or according to the desired deformation of the deformable plate 2.

[0082] Thus, the shape of the legs 5 can play some important role in the deformation of the deformable plate 2. For example, each leg 5 may be substantially flat and have an approximately rectangular shape, as in most figures, or as in FIG. 12, have a trapezoidal shape, with the larger base of the trapezoid forming a proximal end 24, for example, at the level of the peripheral edge 11, and the smaller base of the trapezoid forming a distal end 25, for example, further away from the deformable plate 2. FIGS. 7-10 specifically show substantially rectangular legs 5, with the peripheral edge 11 of the deformable plate 2 forming a circle; FIG. 12 shows a trapezoidal leg 5 with a smaller base that is much smaller than the larger base, with the peripheral edge 11 of the deformable plate 2 forming a hexagon; and FIG. 13 then shows a slightly trapezoidal leg 5 with a smaller base that has a size relatively close to that of the larger base, with the peripheral edge 11 of the deformable plate 2 again being a circle.

[0083] The fixed part 23 and the mobile part 22 belonging to the same one of the legs 5 are preferably separate from each other and are located at a distance from each other along the leg 5 .

[0084] Advantageously, and as represented in the figures, at least one of the legs 5 (or several or all of them) extends, at rest, substantially according to a second mean plane of extent P' (if this concerns several legs 5 or all legs 5, respectively). Thus, at rest, i.e. preferably in the absence of any deformation mechanical load applied to the deformable plate 5, for example by an actuator, the plate advantageously has an extent inscribed in the second mean plane of extent P' (or in the immediate vicinity of or on either side of the second mean plane of extent P'), which preferably intersects the deformable plate 5 over most or almost all of its thickness. According to a first embodiment shown in most figures, at rest at least one of the legs 5 (or several or all of them) has a substantially planar surface. According to a second embodiment shown in FIG. 6 (non-limiting example), at rest at least one of the legs 5 (or several or all of them) has a curvature, preferably continuous, at rest. Alternatively, at least one of the legs 5 (or some or all of them) has, at rest, a primary portion which is substantially planar and a secondary portion which preferably has a continuous curvature.

[0085] According to a particular embodiment and as shown in Figures 1, 2 and 7 to 14, at least one or several of the legs 5 (or all of them) extend substantially continuously with the deformable plate 2 at rest, preferably continuously with the first mean plane of extent P. The first mean plane of extent P is therefore advantageously parallel to or coincides with the (corresponding) second mean plane of extent P'. Thus, at rest, i.e. preferably in the absence of any deforming mechanical load applied to the deformable plate 2, the deformable plate 2 and one, several or all of the legs 5 continuous therewith advantageously extend according to the same continuous and regular, advantageously straight, profile, which may alternatively be in a stepped shape, the legs 5 and the deformable plate 2 considered then respectively forming first and second parallel staircase steps, the two steps being at different heights, the first mean plane P and the second mean plane P' then being parallel and not coinciding. For example, at least one of the legs 5 (or some or all of them) projects outward from the deformable plate 2, from a peripheral edge 11 of the deformable plate 2. The legs 5 are therefore preferably arranged contiguous with and transverse to the deformable plate 2.

[0086] According to another particular embodiment and as shown in Figures 3 to 6, the (corresponding) second mean plane of extension P' intersects with the first mean plane of extension P. Thus, at rest, i.e. preferably without any deforming mechanical load applied to the deformable plate 2, the deformable plate 2 and its contiguous legs 5 advantageously extend according to the same continuous profile with at least one angle, which angle separates the deformable plate 2 from the leg 5 under consideration. Thus, according to this embodiment, the first mean plane of extension P and the second mean plane of extension P' do not coincide. Thus, according to this embodiment, at least one of the legs 5 extends, at rest, substantially obliquely or perpendicularly to the deformable plate 2.

[0087] More preferably, the second mean plane P' of the extent forms a dihedral angle p with the first mean plane P of the extent. For example, as shown in FIG. 5, the first mean plane P and the second mean plane P' of the extent are orthogonal. In other words, according to this embodiment, the first mean plane P of the extent intersects the second mean plane P' of the extent laterally, and the dihedral angle β is advantageously perpendicular, i.e., substantially equal to 90°. According to another embodiment, as shown in FIGS. 3, 4, and 6, the first mean plane P and the second mean plane P' of the extent are oblique to each other. The dihedral angle β may be an acute or obtuse angle, i.e., between 0° and 90° (excluding the end points) or between 90° and 180° (excluding the end points), respectively. More preferably, the dihedral angle β is between 30° and 60° or between 120° and 150°. In the embodiment shown in FIG. 6 , in which the legs 5 have a curvature, the second mean plane of extent P′ is preferably oblique to the first mean plane P and intersects with the first mean plane P, the dihedral angle p between these two planes being advantageously obtuse. Advantageously, any useful combination of different legs 5 can be implemented, each extending according to a corresponding second mean plane of extent P′ that coincides with, is parallel to, or intersects with the first mean plane of extent P, the corresponding second mean planes P′ themselves being coincident, parallel, or intersecting with each other. Preferably, the secondary fabrication step includes a step of folding at least one of the legs 5, such that the leg 5 extends substantially obliquely or perpendicularly to the deformable plate 2. For example, the leg 5 extends according to the second mean plane of extent P′, the deformable plate 2 extends, at rest, substantially according to the first mean plane of extent P, and the folding step is performed so that the first mean plane of extent P and the second mean plane P′ intersect. More preferably, the folds are not reversible, i.e., advantageously formed to fold the plate 5 inelastically. Figures 4 to 6 show examples of legs 5 attached to the deformable plate 2 resulting from this last step, each leg 5 folded according to a dihedral angle β formed between the first mean plane of extension P and the second mean plane P', the dihedral angles β in Figures 3, 4, 5 and 6 being obtuse, acute, perpendicular and obtuse, respectively.

[0088] Preferably, and as shown in the figures, the deformable plate 2 and legs 5 have first and second thicknesses, respectively, which are, for example, substantially identical. Such a configuration may be advantageous for standardizing the manufacture of the deformable plate 2 and / or legs 5. This is particularly advantageous because the adaptive optical device 1 of the present invention allows for the use of thin or very thin (and therefore easier to deform, but relatively fragile) deformable plates 2 that can be made integrally, while reducing the risk of errors during the manufacture of the adaptive optical device 1. Nevertheless, the present invention is not limited to this preferred embodiment, and it is possible to envisage, for example, different thicknesses, e.g., the second thickness being greater than the first thickness, or vice versa.

[0089] Advantageously, the adaptive optical device 1 also comprises at least one additional actuator 29 designed to apply a force directly to the deformable plate 2, rather than to one of the legs 5, in order to deform it. This additional actuator 29 therefore advantageously makes it possible to locally complete or refine the global action of the peripheral actuators 7. In particular, the additional actuator 29 is designed to apply a point or near-point force to the deformable plate 2, or alternatively to apply a force distributed over the surface of the deformable plate 2. For example, the additional actuator 29 is formed by at least one piezoelectric film provided over the surface of the deformable plate 2 (in particular over the hidden face 4), which is intended to generate a bimetallic effect that, when an electric current is applied to the piezoelectric film, causes the deformable plate 2 to bend at least locally.

[0090] The adaptive optical device 1 may further comprise at least one central actuator 27 designed to apply a force (preferably approximately point-wise) to the geometric center C, as shown in Figures 10 and 12, where the central actuator 27 thus forms the or one of the additional actuators 29. The additional actuator(s) 29 can also be connected to the plate 2 at other locations than the geometric center C, as shown by the embodiment of Figure 13, in which the adaptive optical device 1 comprises four additional actuators 29, specifically arranged around the geometric center C of the deformable plate 2 on the side of the hidden surface 4, and at a distance from the geometric center C, as well as the embodiment of Figure 14, in which the adaptive optical device 1 comprises two additional actuators 29, specifically arranged on either side of the geometric center C of the deformable plate 2 on the side of the hidden surface 4, and at a distance from the geometric center C.

[0091] Advantageously, the additional actuator 29 (e.g., central actuator 27) is designed to apply a (e.g., central) pressure or tension to the deformable plate 2 on the side of and via the hidden surface 4. Advantageously, the (e.g., central) pressure or tension deforms the deformable plate 2 to introduce or correct an aberration, for example an elliptical aberration, in the incident wavefront when it is reflected by the incident surface 3 and / or refracted through the deformable plate 2. Preferably, the aberration is changed at least locally at the level of the deformable plate 2 (e.g., at the level of the geometric center C) according to the force applied by the additional actuator 29 (e.g., central actuator 27) on the hidden surface 4. Naturally, the adaptive optical device 1 can be equipped with several additional actuators 29 (central or not) of the same or different types, in particular as described above and / or below, in combination. Advantageously, the additional actuator 29 (e.g., the central actuator 27) may be of any type (piezoelectric, magnetic, two-part, mechanical, threaded, etc.), including those known in the considered technical field. For example, the additional actuator 29 (e.g., the central actuator 27) is connected to the hidden face 4 via an adhesive point (e.g., at the level of the geometric center C) and transmits a tensile or compressive force locally to the surface of the hidden face 4, thereby deforming the deformable plate 2. Even more advantageously, the force is therefore applied according to a direction locally substantially perpendicular to the incidence face 3.

[0092] Each peripheral actuator 7 and / or additional actuator 29 (e.g., central actuator 27) preferably has a first part fixed (i.e., fixedly attached) to the corresponding leg 5 and a second part fixed to the frame 21, the first and second parts themselves being translationally connected to each other, for example in the case of piezoelectric-type peripheral actuators 7 and / or additional actuators 29 (preferably with approximately point forces in this case), or not fixed to each other, for example in the case of magnetic-type peripheral actuators 7 and / or additional actuators 29. For example, specifically during the mounting step, the first part is glued to the corresponding leg 5 by means of a drop of adhesive, advantageously having, for example, a substantially cylindrical, conical or frusto-conical head immersed in the drop without coming into contact with the corresponding leg 5, the drop thereby forming a ball-joint connection between the head and the corresponding leg 5. In particular, this makes it possible to avoid that the considered peripheral actuator 7 and / or additional actuators 29 (e.g. central actuator 27) cause deformations of the surface of the deformable plate 2 by mere effect of their connection with the deformable plate 2 (e.g. if the considered actuator is the central actuator 27) or the legs 5 (e.g. if the considered actuator is the peripheral actuator 7), even in the absence of any deformation mechanical load of the actuator.

[0093] 10 shows an example of the manufacture of the deformable plate 2 and the legs 5 attached to it, which legs 5 are also integral with the deformable plate 2 in this case and are formed during the common step of cutting the blank plate 12. Then, on the side of the hidden face 4, each of the peripheral actuators 7 is connected to one of the respective legs 5, so that each leg 5 is provided with at least one peripheral actuator 7, thereby defining the movable part 22 of the leg 5 considered, which is connected to the peripheral actuator 7. An additional actuator 29, for example a central actuator 27, is also arranged on the side of the hidden face 4 at the level of the geometric center C of the deformable plate 2. Finally, the deformable plate 2 and the attached legs 5 are placed in the center of the ring 8, with the distal ends 25 of the legs 5 fitting into shoulders 26 of the ring 8, which abut the legs 5, which are then connected to the ring 8 by riveting, screwing, brazing, gluing, or welding, whereby the ring 8 herein forms at least one part of the frame 21, thereby defining the fixed portion 23. Optionally, the adaptive optical device 1 also includes a cap 28, for example, having an opening in its center, designed to define the entrance surface 3 of the deformable plate 2, more specifically, the optical surface of the entrance surface 3, i.e., the optically active part of the entrance surface 3. In the embodiments of FIGS. 9, 10, and 15, the cap 28 is placed on the deformable plate 2 on the entrance surface 3 side so as to fit into the shoulders 26. FIG. 11 partially illustrates an alternative manufacture, where only the secondary fabrication step is represented, in which the portion 5 is formed separately from the deformable plate 2 and then attached to the deformable plate 2 .

[0094] An example of the use of the aforementioned adaptive optical device 1 is now disclosed. According to this example, it is desirable to correct optical aberrations observed in a wavefront using an adaptive optical device, which may be a deformable mirror or an adaptive lens. Therefore, the adaptive optical device 1 is positioned in the path of the wavefront so that the entrance surface 3 of the deformable plate 2 intercepts the wavefront and deforms it, specifically reflecting and / or refracting it. Generally, this interference alone is not sufficient to correct the observed optical aberrations; it is necessary to correct the deformations (reflection and / or refraction) caused by the entrance surface 3 and / or the deformable plate 2 to sufficiently modify the wavefront. For this purpose, the deformable plate 2 to which the entrance surface 3 belongs must be deformed in a determined, precise, and often localized manner so that the entrance surface 3 curves (or flattens), specifically with a determined and constant angle of curvature. Thus, at least one peripheral actuator 7 is actuated to displace (and optionally deform) in a controlled manner the movable part 22 of one of the legs 5 to which it is connected, by pushing or pulling it, i.e., by displacing it towards the entrance face 3 or towards the opposite hidden face 4 of the adaptive optical device 1. The displaced movable part 22 causes a slight deformation of the deformable plate 2 to which it is fixed via the peripheral edges 11 connecting the deformable plate 2 and the legs 5. The deformation of the deformable plate 2 is limited and fully controlled by the presence of the fixed parts 23 of the legs 5, which are fixedly connected to the frame 21 and therefore remain immobile relative to the frame 21, at least in translation, during and after the displacement of the movable part 22. It is possible to sequentially or simultaneously activate several peripheral actuators 7 and possibly at least one additional actuator 29, e.g., a central actuator 27, in order to deform the deformable plate 2 sufficiently so that its entrance surface 3 receives the incident wavefront according to the determined angle and deformation of the deformable plate 2 so as to correct the optical aberrations.Thus, Figure 15 shows a configuration in which one or several movable parts 22 are displaced by their respective peripheral actuators 7 (hidden in the figure by caps 28), and the respective fixed parts 23 are not displaced at all when they are connected to the frame 21.

[0095] The adaptive optical device 1 can then be set to an inoperative position and the displaced legs 5 are set back to their starting position contiguous to the deformable plate 2, in particular by their elastic behavior, by deactivation of the peripheral actuators 7 and by the biasing or holding force exerted by the fixed parts 23 of the legs 5 on the remaining parts of the legs 5 and therefore on the deformable plate 2.

[0096] Another example of the use of the adaptive optical device 1 according to the present invention is described below, but this example does not constitute any limitation regarding the possible uses of the adaptive optical device 1 according to the present invention. According to this example, the adaptive optical device 1 modifies the shape of an incident wavefront. The incident wavefront is deformed, e.g., reflected and / or refracted, by the deformable plate 2, thereby resulting in a deformed, e.g., reflected and / or refracted, wavefront. Depending on the geometry of the deformable plate 2, in particular of the entrance surface 3, the incident wavefront has a phase relative to the reflected and / or refracted wavefront and is therefore locally advanced or delayed. Depending on their selected actuation combination and their arrangement within the adaptive optical device 1, the peripheral actuators 7 (possibly in combination with additional actuator(s) 29) enable the latter to generate different Zernike polynomials in the deformed wavefront (in particular, not present in the incident wavefront). Thus, by actuating one or several peripheral actuators 7 (and possibly additional actuator(s) 29), it is possible to generate different Zernike polynomials such that the deformable plate 2 introduces one or several optical aberrations into the incident wavefront, such as astigmatism, "defocus", "trifoil", and / or coma. Different actuations, described above or not described above, of the peripheral actuators 7 (and optionally one or several additional actuators 29, in particular the central actuator 27) can be combined together to generate or correct more complex optical aberrations.

[0097] It will be appreciated that any combination of the different embodiments and variants described hereinabove is possible, as may be deemed relevant to the technical field considered for creating a suitable adaptive optical device.

[0098] Optionally, forming the deformable plate 2 can include fixing a central plate, in particular by gluing, brazing and / or welding, onto the blank plate 12, which advantageously comprises the entrance surface 3. The blank plate 12 is preferably made of a cheaper material than the material from which the central plate is made, since it allows the legs 5 to be formed at advantageous cost, for example by cutting, from the blank plate 12. Indeed, the deformable plate 2 must preferably have an excellent surface quality, and therefore the material from which it is made is generally very expensive, while the legs 5 only need to have suitable mechanical properties (especially elasticity) and not specific surface requirements.

[0099] Preferably, the common cutting step and / or the second cutting step comprises a selective etching operation.

[0100] According to a particular embodiment, the manufacturing method further comprises a reflective treatment step of the entrance surface 3 to form a reflective surface, the adaptive optical device 1 being a deformable mirror. Preferably, the reflective treatment step comprises covering the entrance surface 3 with a reflective coating. For example, this coating step can comprise a scattering of reflective elements over the entrance surface 3 so as to form a reflective surface at the level of the entrance surface 3 that can reflect the wavefront. According to one embodiment, the reflective treatment step is applied to a central plate on the side of the entrance surface 3 to form the reflective surface.

[0101] The adaptive optical device 1 of the present invention, preferably obtained by the manufacturing method of the present invention, makes it possible to perform very fine operations of modifying the incident wavefront in an adaptive optical system by reflection and / or refraction of the wavefront, thereby allowing controlled servicing and manufacturing costs by simple, precise and fast setup.

[0102] Industrial Applicability The present invention finds its industrial application in the design, manufacture and use of adaptive optics devices.

Claims

1. An adaptive optical device (1) comprising a deformable plate (2) intended to deform an incident wavefront by refraction and / or reflection, comprising at least: legs (5) fixedly attached to the deformable plate (2); a frame (21) fixed to said deformable plate (2); a plurality of peripheral actuators (7); Further provided with each leg (5) comprises a movable part (22), each of said movable parts (22) being connected to at least one of said peripheral actuators (7), each of said at least one peripheral actuator (7) being capable of locally deforming said leg (5), said leg (5) transmitting a deformation force to said deformable plate (2); each leg (5) further comprises a respective fixed part (23) fixedly attached to said frame (21) so as to be immobilized relative to said frame (21); characterized in that Adaptive optical device (1).

2. 2. Adaptive optical device according to claim 1, characterized in that the fixed part (23) cannot perform a translational movement according to at least one fastening direction (F) relative to the frame (21).

3. The fixed part (23) is in embedded connection with said frame (21) and does not have any degree of freedom relative to said frame (21); or in pivotal connection with the frame (21) or in ball joint connection with the frame (21); 3. An adaptive optical device according to claim 1 or 2, characterized in that it comprises:

4. 4. The adaptive optical device according to claim 1, wherein each leg (5) extends between a respective proximal end (24) attached to the deformable plate (2) and a respective distal end (25) opposite the proximal end (24).

5. 5. Adaptive optical device according to claim 4, characterized in that the fixed part (23) comprises the distal end (25) and is therefore fixedly attached to the frame (21).

6. 6. Adaptive optical device according to claim 4 or 5, characterized in that the movable part (22) is arranged between the distal end (25) and the proximal end (24).

7. The adaptive optical device according to any one of claims 4 to 6, characterized in that the movable part (22) is arranged closer to the proximal end (24) than to the distal end (25).

8. The adaptive optical device according to any one of claims 4 to 6, characterized in that the movable part (22) is arranged equidistant between the proximal end (24) and the distal end (25).

9. The adaptive optical device according to any one of claims 4 to 6, characterized in that the movable part (22) is arranged closer to the distal end (25) than to the proximal end (24).

10. Adaptive optical device according to any one of claims 4 to 9, characterized in that the fixing portion (23) is located closer to the distal end (25) than to the proximal end (24).

11. Adaptive optical device according to any one of claims 1 to 10, characterized in that each leg (5) is substantially flat and has an approximately rectangular or trapezoidal shape.

12. 12. An adaptive optical device according to any one of claims 1 to 11, characterized in that the deformable plate (2) and the legs (5) attached to the deformable plate (2) together form a monolithically deformable body in the form of a star with several branches, each branch being formed by one of the legs (2).

13. 13. The adaptive optical device according to any one of claims 1 to 12, characterized in that the frame (21) comprises a rigid ring (8) in the center of which the deformable plate (2) comprising the legs (5) is arranged.

14. 14. Adaptive optical device according to claim 13, characterized in that the rigid ring (8) has an inner shoulder (26) to which the legs (2) are fixed.

15. An adaptive optical device (1) according to any one of claims 1 to 14, characterized in that one or more of the legs (5) extend substantially continuously with the deformable plate (2) when at rest.

16. The adaptive optical device (1) according to any one of claims 1 to 15, characterized in that at least one of the legs (5) extends substantially obliquely or perpendicularly to the deformable plate (2) when at rest.

17. 17. An adaptive optical device (1) according to any one of claims 1 to 16, characterized in that the deformable plate (2) extends, at rest, according to a first imaginary plane (P) and at least one of the legs (5) extends, at rest, according to a second imaginary plane (P').

18. 18. Adaptive optical device (1) according to claim 17, characterized in that the first imaginary plane (P) is parallel to or coincides with the second imaginary plane (P').

19. 18. The adaptive optical device (1) according to claim 17, characterized in that the second imaginary plane (P') intersects with the first imaginary plane (P), and the first imaginary plane (P) and the second imaginary plane (P') intersect.

20. The adaptive optical device (1) according to any one of the preceding claims, characterized in that it also comprises at least one additional actuator (29) designed to apply a force directly to the deformable plate (2) and thereby deform the deformable plate (2).

21. Adaptive optical device (1) according to any one of claims 1 to 20, characterized in that the deformable plate (2) has a geometric centre (C).

22. 22. Adaptive optical device (1) according to claim 21, characterized in that it further comprises at least one central actuator (27) designed to apply a force to said geometric centre (C).

23. 23. Adaptive optical device (1) according to claim 21 or 22, characterized in that each leg (5) extends from the deformable plate (2) in a radial direction relative to the geometric center (C).

24. Adaptive optical device (1) according to any one of claims 21 to 23, characterized in that the legs (5) are uniformly angularly distributed around the geometric centre (C).

25. Adaptive optical device (1) according to any one of claims 1 to 24, characterized in that the legs (5) are integral with the deformable plate (2).

26. An adaptive optical device (1) as described in any one of claims 1 to 25, characterized in that it has at least four legs (5).

27. Adaptive optical device (1) according to any one of claims 1 to 26, characterized in that it constitutes a deformable mirror and / or an adaptive lens.

28. A method for manufacturing an adaptive optical device (1) comprising the primary step of making or preparing a deformable plate (2) intended to deform an incident wavefront by refraction and / or reflection, comprising at least: a secondary step of making legs (5) fixedly attached to said deformable plate (2); an installation step, in which each of the movable parts (22) of each leg (5) is connected to a respective one of at least one actuator (7), said at least one respective actuator (7) being capable of locally deforming said leg (5), said leg (5) transmitting a deformation force to said deformable plate (2); a fastening step in which the respective fixed portion (23) of each leg (2) is fixedly attached to a frame (21) fixed relative to the deformable plate (2) so as to be immobilized relative to the deformable plate (2); Further comprising: characterized in that method.

29. 29. The method of claim 28, wherein the primary and secondary steps occur at least partially simultaneously, and the primary and secondary steps include a common step of cutting a blank plate (12) to form the legs (5) and the deformable plate (2), the legs (5) being integral with the deformable plate (2).

30. 29. A manufacturing method according to claim 28, characterized in that said secondary step comprises fixing said legs (5) to said deformable plate (2).

31. During the fixing step, at least one portion of the leg 5 On the edge of the deformable plate 2, on the deformable plate 2, and / or Below the deformable plate 2, 31. A method according to claim 30, characterized in that it is fixed to the deformable plate (2).

32. Method according to any one of claims 28 to 31, characterized in that during the fastening step, the legs (5) are riveted, screwed, glued, brazed and / or welded to the frame (21).

33. 33. The manufacturing method according to any one of claims 28 to 32, characterized in that the deformable plate (2) has an entrance surface (3) intended to receive the wavefront, the method further comprising a step of reflective treatment of the entrance surface (3) to form a reflective surface, and the adaptive optical device (1) is a deformable mirror.

34. 34. A method according to claim 33, characterized in that the reflective treatment step comprises covering the entrance surface (3) with a reflective coating.

35. A method according to any one of claims 28 to 34, characterized in that the secondary step comprises folding at least one of the legs (5) so that it extends substantially obliquely or perpendicularly to the deformable plate (2).

36. An adaptive optical device (1) as described in claim 19, characterized in that the first virtual plane (P) and the second virtual plane (P') are orthogonal to each other.

37. A manufacturing method as described in claim 30, wherein the legs (5) are fixed to the deformable plate (2) by welding, gluing, and / or brazing.

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