METHOD FOR PRODUCING A MICRO- OR NANO COMPONENT MADE OF GLASS-LIKE MATERIAL AT THE END OF A STRUCTURE BY PHOTOPOLYMERIZATION WITH MULTIPLE PHOTONES

Description

TECHNICAL FIELD

[0001] This application relates to the field of photonics and optical devices and in particular the realization of a device consisting of an optical and / or photonic component, made by additive manufacturing and having small dimension patterns, in particular micrometric or even nanometric, which are placed at the end or on a lateral region of a waveguide type structure, in particular an optical fiber or of an electronic board or a photonic circuit. PREVIOUS STATE OF THE ART

[0002] In the field of photonics and optical devices, new 3D printing or additive manufacturing processes have emerged to produce optical components with small patterns.

[0003] The document "Three-dimensional printing of transparent fused silica glass", by Kotz et al., Nature, vol. 544, 2017, presents, for example, a method for creating optical structures with patterns several tens of micrometers in size, from a silica powder suspended in a resin capable of polymerizing under the action of light radiation.

[0004] This material is exposed using a process called stereolithography, which employs a laser light source whose wavelength is partially absorbed by the material. Structured illumination triggers polymerization in specific areas. To obtain a silica-based structure, the process then involves annealing the structure at high temperature to eliminate any organic traces, leaving only silica glass. With this process, the resolution of the patterns is limited.

[0005] A process known as "two-photon polymerization" has emerged, enabling the fabrication of microstructures or nanostructures with high resolution, typically sub-micrometer and potentially on the order of hundreds of nanometers. Two-photon polymerization, as a direct laser writing technique, allows the creation of three-dimensional (3D) structures. This technique relies on the use of femtosecond or picosecond lasers, which deliver laser pulses ranging from a few femtoseconds to several picoseconds, particularly hundreds of picoseconds. Two-photon polymerization employs an optical process based on the simultaneous absorption of two photons in a photosensitive material or in a material to which a photoinitiator has been added. When exposed to the laser, the material is modified by activating photoinitiators, which triggers the formation of free radicals.These free radicals activate the monomeric units, thus triggering the polymerization reaction locally under the action of an activator, in this case, laser light. In the case of two-photon polymerization, the photopolymerization reaction of the material occurs within the focal volume, where the light energy associated with each laser pulse is concentrated. Scanning this focal zone within the material volume allows the creation of a three-dimensional structure. In a subsequent step of the process, the unpolymerized material can be removed by dilution in a solvent.

[0006] Furthermore, the assembly or anchoring of a microstructured or nanostructured polymer component onto a support or optical component, or even onto the end of an optical fiber, poses a problem.

[0007] For example, the paper "Optical fiber tip with integrated Mach-Zehnder interferometer for sensor applications," by Gaso et al., published in Advances in Electrical and Electronic Engineering, vol. 17, 2019, presents the fabrication of a component with a Mach-Zehnder interferometric structure whose patterns are made of a polymer material. To be placed on the fiber, the component is fitted onto one end of the fiber. The connection between the fiber and the component is therefore not strong: only friction between the two structures ensures that the 3D-printed structure remains attached to the optical fiber. Furthermore, a polymer structure is less thermally stable and exhibits lower optical transmission than a glass structure, such as silica.

[0008] The two-photon polymerization process can be adapted to glass systems. For example, the paper by Kotz et al., "Two-photon polymerization on nanocomposites for the fabrication of transparent fused silica glass microstructures," published in Advanced Materials 2021, describes a two-photon polymerization process for an organic material loaded with silica particles to form a three-dimensional structure. Once exposed to the laser, the material is heat-treated to remove the organic fraction, thus performing sintering. This sintering is carried out at a high temperature exceeding 1000°C. The final result is a silica structure. However, the heat treatment used to remove the organic fraction causes a change in the dimensions of this structure, known as "shrinkage," with a reduction factor that can be on the order of 30%.Such a constriction can therefore lead to difficulties in precisely positioning the 3D-printed component at the end of an optical fiber. It is essential to ensure that the 3D-printed structure remains aligned with the optical core, which guides light within the optical fiber and allows the microcomponent to be characterized. This constriction also induces deformations at the substrate-component interface, altering the microstructure and thus the optical properties. Furthermore, this constriction induces significant stresses at the substrate-component interface, resulting in the component becoming detached from its support.

[0009] To solve this adhesion problem, one or more adhesion layers can be introduced between the fiber and the 3D structure, for example through the formation of silanes. However, this approach may prove insufficiently robust for use in certain types of environments, particularly at high temperatures (above 600°C), or in environments where significant radiation and / or vibrations are present.

[0010] The problem thus arises of finding a new process enabling the assembly of a micro-structured or nano-structured optical and / or photonic component printed by multi-photon polymerization, in particular two-photon polymerization, on a structure such as a waveguide and in particular an optical fiber, and which is improved with regard to the disadvantages stated above.

[0011] Prior art is disclosed in publication WO 2017 / 059960 A1. DESCRIPTION OF THE INVENTION

[0012] One embodiment of the present invention relates to a method for manufacturing an optical device equipped with a nanostructured or microstructured component assembled on an end or a lateral surface of a structure, the method comprising steps consisting of: provide a support based on a first material, photosensitive and transformable into a glassy material, and produce on a first end of said support, by photopolymerization with several photons, in particular with two photons, a micro-structured or nano-structured component, based on a second photosensitive material and transformable into a glassy material, carry out one or more heat treatments so as to transform the first material of said support and the second material of said micro- or nano-structured component into a glassy material then, assemble and join, a region of a second end of said support opposite said first end with an area of ​​an end or a lateral surface of said structure.

[0013] The structure onto which the nanostructured or microstructured component is assembled can be an optical fiber or, more generally, an optical waveguide. Typically, the substrate and the fiber are joined by welding. This welding can be performed using a material fusion process with an electric arc or with a laser fusion process.

[0014] Using an intermediate support, also called a pedestal or pedestal support, to assemble the component with a fiber or optical waveguide helps to protect this component during this assembly where a localized fusion is performed.

[0015] The localized fusion of a support made of vitreous material and a fiber typically also made of vitreous material and typically silica also makes it possible to obtain a solid assembly.

[0016] Performing thermal annealing before fiber-to-support assembly allows for precise positioning of the support relative to the fiber, as it avoids post-assembly thermal shrinkage, which can lead to misalignment, particularly in the case of non-uniform shrinkage. Advantageously, the process can also include a step of forming at least one waveguide within a volume of the support.

[0017] Depending on one possible implementation of the process, the waveguide(s) can be produced by forming galleries in the support, these galleries typically being formed during an additive manufacturing process of said support.

[0018] According to one possible implementation of the process, the waveguide(s) can be formed after fabrication of said component on said support and prior to said one or more heat treatments.

[0019] Alternatively, it is possible to plan to produce the waveguide(s) after assembly and securing of said region of said support and said area of ​​said structure.

[0020] According to one possible implementation of the process, the waveguide(s) can be produced by direct writing using a laser in a volume of said support.

[0021] A particular implementation involves the creation of several waveguides in said support.

[0022] Advantageously, the support can be produced by multi-photon photopolymerization, particularly two-photon photopolymerization. Thus, the support and the component can be formed in the same step, or at least using the same equipment.

[0023] The microstructured or nanostructured component is typically an optical or photonic component, or a sensor with an optical or photonic component. This optical or photonic component can be chosen in particular from the following components: an interferometer, a lens or lens array, a Fresnel lens array, a diffractive structure, a diffraction grating, a diffractive optical element, a mode adapter, a fiber core combiner, a resonant cavity for optical or acoustic waves.

[0024] Advantageously, the material of said support and / or the material of said component is: a polymer compound loaded with particles of vitreous material such as silica particles, or a sol-gel material.

[0025] According to another aspect, an embodiment of the present invention provides for an optical device equipped with a nano-structured or micro-structured component assembled on one end of an optical fiber, by means of a support made of vitreous material on which the nano-structured or micro-structured component is arranged, the support being welded to an area of ​​said optical fiber and comprising a waveguide which extends between said component and the optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be better understood upon reading the description of the given exemplary embodiments, provided for illustrative purposes only and in no way limiting the application, with reference to the accompanying drawings in which: THE figures 1 and 2serve to illustrate a step in the additive manufacturing process of creating a pedestal support from a photosensitive material that can be transformed into a vitreous material; The figure 3 serves to illustrate a step in the formation of a micro- or nano-structured component at the end of the pedestal support, the component also being made of a photosensitive material and transformable into a vitreous material; The figure 4 serves to illustrate a step in the formation of a waveguide within the volume of the pedestal support, extending from one end to the other end on which said component is located; The Figures 5A and 5B serve to illustrate a heat treatment step to transform the material of the pedestal support and the component into a vitreous material, typically leading to a reduction in their dimensions; The figure 6 serves to illustrate an assembly step of the pedestal support equipped with the component and an end zone of an optical fiber; The figures 7 , 8 and 9serve to illustrate the fabrication of a waveguide in a pedestal support after heat treatment aimed at transforming the material of this support into a glassy material; The Figures 10 And 11 These serve to illustrate the construction of a waveguide in a pedestal support after assembly of this support with an optical fiber; The figure 12 serves to illustrate a step in the formation of a pedestal support by additive manufacturing, the support being equipped with hollow galleries delimiting a waveguide; The figure 13 serves to illustrate a pedestal support with multiple waveguides traversing it, each waveguide being associated with a component; The figure 14 serves to illustrate a waveguide in a pedestal support, the waveguide having a curved geometry and terminating in an off-center end zone of the pedestal support; The figure 15serves to illustrate a waveguide for a pedestal support having a curved geometry and opening into a lateral region of the support; The figure 16 serves to illustrate a pedestal support equipped with a component and assembled on a lateral region of an optical fiber;

[0027] Identical, similar or equivalent parts of the different figures carry the same numerical references in order to facilitate the transition from one figure to another.

[0028] The different parts represented in the figures are not necessarily shown on a uniform scale, in order to make the figures more legible. DETAILED DESCRIPTION OF SPECIFIC METHODS OF IMPLEMENTATION

[0029] We now refer to figures 1 and 2 used to illustrate a step in the formation of a support 10, also called a "pedestal", intended to accommodate a micro- or nano-structured optical and / or photonic element or component.

[0030] The support 10, in the illustrated example, has a cylindrical shape, specifically a cylinder of revolution, with a length L that can typically range from 0.1 to 10 mm, for example, on the order of 1 mm, and a width D (in this example, corresponding to the diameter of its base) that can range from 10 microns to several millimeters in diameter. This dimension D may itself depend on the diameter of an optical fiber with which this support is intended to be subsequently assembled and on a shrinkage factor, also called "thermal shrinkage," that the support 10 may undergo during a subsequent heat treatment stage aimed at modifying its composition. The diameter of the support 10 is preferably designed so that it is contained within the end of the optical fiber with which it is assembled.The support 10 can at this stage be designed with a diameter larger than that of the fiber 30, sufficiently so to allow it to adjust to the diameter of the fiber 30 after thermal shrinkage. The dimension D can, for example, be between 100 and 400 µm, particularly if considering an optical fiber with an outer diameter of 80 µm or 250 µm.

[0031] The geometric shape of support 10 is not limited to the illustrated example, and support 10 may take other shapes than a cylinder, for example, a parallelepiped shape or a hexagonal cylinder. Since support 10 is typically produced by additive manufacturing, its dimensions may also depend on the manufacturing process used and, in particular, on the capabilities of the printing machine used for this production.

[0032] A 10-pedestal support with a narrowed shape from one end to the other, or with a curve, may be provided.

[0033] The additive manufacturing process is advantageously a multi-photon photopolymerization process, in particular two-photon, but other printing techniques with lower resolutions, for example single-photon photopolymerization, can be used for this step or three-photon or multi-photon photopolymerization.

[0034] During this step, a 3D printing machine such as the one marketed by Nanoscribe under the name Photonic Professional GT2® can be used. The operating wavelength of the laser used is adapted by a person skilled in the art according to the material of the support being used.

[0035] The support 10 can thus be formed from a material 12, such as a resin or a polymer, that can be transformed into a glassy material and, in particular, loaded with photoinitiators. A polymer compound loaded with particles of glassy material or a so-called "sol-gel" material that allows a glassy material to be obtained by the sol-gel process can be used.

[0036] In the case of a photosensitive material in the form of a particle-loaded polymer compound, these glassy material particles, such as silica (SiO2) particles, are typically nanoparticles. "Nanoparticles" are defined as particles with dimensions between 1 nm and 100 nm, and in particular between 10 nm and 50 nm.

[0037] The support material 12 can be, according to one particular embodiment, a material such as that described in the paper by Doualle et al., "3D printing of silica glass through a multiphoton polymerization process," 2021, formed from a mixture of HEMA-hydroxyl-ethyl-methacrylate monomer in a phenoxyethanol (POE) solvent. Silica nanoparticles, for example, several tens of nanometers in diameter, particularly on the order of 40 nm, are dispersed in this preparation. A photoinitiator (2,2-dimethoxy-2-phenylacetophenone) is added to enable two-photon polymerization.

[0038] According to another specific embodiment, a precursor material such as that described in the article "Three-dimensional printing of transparent fused silica glass" by Frederik Kotz et al., published in the journal Nature in 2017, is used. Small-diameter silica particles are dispersed within a monomer. Exposure using a laser triggers polymerization during the three-dimensional printing of the support.

[0039] Another example uses Material 12, as described in the article "Two-photon polymerization of nanocomposites for the fabrication of transparent fused silica glass microstructures" by Frederik Kotz et al., published in March 2021 in the journal "Two Advanced Materials". Material 12 is a resin manufactured by Glassomer and loaded with silica nanoparticles dispersed within a monomer.

[0040] According to another possibility, a compound with TiO2 / SiO2 particles and as described for example in the document "Microfabrication by two-photon lithography, and characterization, of SiO2 / TiO2 based hybrid and ceramic microstructures" by Desponds et al., Journal of Sol-Gel Science and Technology volume 95, pages 733-745 (2020) can be used.

[0041] Thus, the material used can be a polymer loaded with other types of glassy material particles besides silica particles. In particular, TiO2 nanoparticles or alumina nanoparticles can be used, or even silica nanoparticles doped with a rare earth element, for example Erbium, or silica nanoparticles doped with Germanium.

[0042] Another possible implementation involves using a sol-gel compound incorporating alkoxide precursors, which allows for the production of a glassy material through polymerization and heat treatment. Such a material is described, for example, in the paper "Sol-Gel Derived Optical and Photonic Materials," Woodhead Publishing Series in Electronic and Optical Materials, 2020, pp. 315-346. This type of material offers greater flexibility in obtaining a doped glassy material. The resulting material is typically more homogeneous than that produced with a material containing silica nanoparticles.

[0043] In the case where support 10 is formed by two-photon polymerization (TPP), a picosecond or femtosecond laser is typically used for this fabrication. The laser can have a wavelength in the infrared, for example at 1030 nm, or in the near-infrared, for example at 800 nm, or in the visible spectrum. The laser pulses can range in duration from several femtoseconds to 700 ps, ​​typically between several femtoseconds and several picoseconds.

[0044] Frequency doubling or tripling with wavelengths of 515 nm, 400 nm, and 266 nm respectively can also be implemented. The laser energy can be expected to range from 1 nanojoule to tens of millijoules. Alternatively, a series of pulses at a frequency, for example, on the order of several tens of MHz, or a single pulse, can be used.

[0045] Next, we manufacture ( figure 3) on a first end 10A of the support 10, a micro-structured or nano-structured component 21. By "micro-structured" component 21, we mean an element 21 having 3-dimensional patterns, and in particular patterns with minimum dimensions typically between 0.1 µm and 100 µm. By "nano-structured" component 21, we mean that the component 21 has 3-dimensional patterns with minimum dimensions typically between 1 and 100 nanometers. The fabricated component 21 can be an optical or photonic component, for example a micro or nano-interferometer, in particular a Fabry-Perot interferometer.Other structures, such as, for example, a plane, concave or convex mirror, a lens, a Fresnel lens, a lens array, or an array of Fresnel lenses, a diffractive structure, a diffraction grating, a diffractive optical element or an imaging device objective can also be manufactured, but also a textured structure for localized Raman effect enhancement, a mode adapter or a combiner for fiber lasers, especially high-power ones where silica is an essential material.

[0046] The optical or photonic component can be used to create a sensor designed to be placed at the end of an optical fiber, enabling the measurement of physical parameters such as pressure, temperature, deformation, and acoustic waves, or chemical / biological parameters such as the concentration of a target biochemical species, for example, based on antibody-antigen reactions. Thanks to the pedestal, the optical component can be added to a microfluidic circuit either to implement optical analysis or detection, or to perform optical treatment, for example, on cells passing through microfluidic channels within the microfluidic circuit.

[0047] Component 21 is preferably produced here by multi-photon photopolymerization, and in particular by two-photon photopolymerization, due to the resolution achievable with this process. Component 21 can be formed from a photosensitive material 22 that can be transformed into a glassy material. Material 22 can be a polymer compound loaded with glassy material particles or a sol-gel material, and in particular such as those mentioned previously for the pedestal.

[0048] The pedestal support 10 and the micro-structured or nano-structured component 21 can potentially be formed from the same material. The pedestal support 10 and the micro-structured or nano-structured component 21 can also be produced using the same equipment, in particular the same additive manufacturing equipment, for example, the same equipment configured for multi-photon photopolymerization, especially two-photon polymerization. Thus, advantageously, the support 10 and the component 21 can be produced in a single multi-photon or two-photon photopolymerization step.

[0049] In this case, a change of objective or lens is typically carried out during the step since the dimensions of component 21 are typically much smaller than those of support 10.

[0050] In the specific implementation example illustrated on the figure 4, after forming the component 21, at least one waveguide 15 is then made passing through the support 10 from the end 10A on which the component 21 is located to a second end 10B of the support opposite to the first end.

[0051] This can typically be achieved by exposing a central volume 152 to a LAS laser, which passes longitudinally through the support 10. This exposure is implemented in such a way as to locally modify the material 12 of the support and, for example, to modify the refractive index of this central volume or to modulate its refractive index locally, in particular to create an alternation of refractive indices, for example, to form a Bragg grating. Such a grating can be used, for example, to measure temperature, pressure, or mechanical deformations.

[0052] A laser can also be used here to perform this step. Typically, the laser beam is radially illuminated by the support 10, in other words, it is directed in a radial direction with respect to a z-axis in which support 10 extends.

[0053] In the example of implementation illustrated on the figure 4 , only one waveguide 15 is made but alternatively, as illustrated on the figure 13 , plan to produce several waveguides 15A, 15B, 15C. This may be the case in particular when forming several micro- or nano-structured components 21A, 21B, 21C at the end of the support 10. The laser used to form the waveguide(s) can be a femtosecond or picosecond laser as described previously.

[0054] The waveguide produced does not necessarily follow a straight direction parallel to the longitudinal axis of the optical fiber.

[0055] Waveguides created with curvatures can be implemented.

[0056] Thus, at least one 15' waveguide can be made with a curved shape and opening, as in the example illustrated on the figure 14 , in an off-center manner at end 10A of the pedestal support 10.

[0057] In another example of an implementation illustrated on the figure 15 , the 15" waveguide has an end opening onto a lateral surface 10C of the support 10.

[0058] One or more thermal annealing steps are then carried out to remove an organic portion of the material(s) 12, 22 constituting the support 10 and the component 21, and to transform this support 10 and this component respectively into a support and a component made of glassy materials. The annealing temperature(s) is / are typically between 300°C and 1700°C, and depends on the photosensitive material used, and in particular on whether it is a filled polymer or a sol-gel material.

[0059] In the case of a photosensitive polymer material loaded with particles, one or more annealing cycles are performed to achieve decomposition of the polymer(s) and sintering. The sintering annealing is typically carried out at a temperature between 1000°C and 1500°C, and more commonly between 1100°C and 1400°C.

[0060] Annealing can also be carried out by supercritical drying, which reduces both the processing time and the annealing temperature. This type of annealing can be used, for example, in the case of a sol-gel material.

[0061] For supercritical drying, the solvent pressure and temperature exceed the coordinates of a critical point C at a critical temperature Tc and a critical pressure Pc. Critical solvent parameters Tc and Pc for low-temperature critical drying are given as examples in the table below. Table I-5: Critical solvent parameters for low-temperature supercritical drying Solvent TC (°C) PC (bar) Carbon dioxide (CO2) 31,1 73,8 Nitrous oxide (N2O) 36,5 72,4 Freon 13 (CClF 3) 28,9 38,6 Freon 23 (CHF 3) 25,9 48,2

[0062] In the aforementioned article "Two-photon polymerization of nanocomposites for the fabrication of transparent fused silica glass microstructures", a sintering temperature of around 1300°C is applied for 2 hours under a vacuum of 0.05 mbar (5 Pa) for the precursor in question.

[0063] Generally, the annealing temperature range depends on the polymer material used. When the polymer is filled with silica particles, temperatures between 800°C and 1300-1500°C are preferred. Other glasses require lower sintering temperatures, starting at 300°C-400°C.

[0064] As previously mentioned, thermal annealing, and in particular sintering annealing, can lead to a shrinkage, also known as "thermal shrinkage," of the structure, as illustrated in the... figures 5A-5B , where we see a reduction in the respective dimensions of the support 10 and the component 21 fixed to this support.

[0065] Once the composition of the support 10 and the component 21 has been modified, the structure formed by this support 10 and this component 21 can then be assembled and secured on an optical fiber 30. The optical fiber 30, or at least its core 32, or at least an area on which the support 10 is to be fixed, is here provided in a vitreous material, for example a silica glass.

[0066] In the example of implementation illustrated on the figure 6The support 10 is positioned on one end 30A of the fiber 30, specifically so that the waveguide 15 created in the support 10 is aligned with the core 32 of the fiber 30. The core 32 and the waveguide 15 are thus arranged against each other on the same axis A'A, parallel to the respective longitudinal axes of the fiber 30 and the support 10. Prior to joining the fiber 30 and the support 10, the optical fiber 30 and the waveguide 15 are aligned. A region of one end 10B of the support 10, opposite the end 10A on which the component 21 is formed, is then joined to an end zone 30A of the optical fiber 30. To achieve this joining, a localized fusion of this region and this zone is performed. For example, a welding process such as is commonly used to weld silica optical fibers together and employing an electric arc 55 may be used.

[0067] The assembly between the support 10 and the fiber 30 allows the component 21 to be securely bonded to the fiber 30 while preserving the component 21 and preventing damage to its potentially fragile patterns. Indeed, it is not the component 31 itself that is melted and bonded to the fiber 30, but rather the intermediate support 10. The assembly between the glassy support 10 and the fiber 30 is thus stronger than if a polymer element were bonded to the fiber 30. Furthermore, performing the assembly between the fiber 30 and the support 10 after the thermal annealing process(es) leading to thermal shrinkage have already been carried out, and given that both elements are made of glassy material, allows for more precise positioning than if the shrinkage annealing were performed after assembly with the fiber.Indeed, support 10 and component 21 may have undergone shrinkage while optical fiber 30 has not.

[0068] As an alternative to electric arc welding, the bond between the fiber 30 and the support 10 can be achieved by laser irradiation. A CO2 laser, advantageously with a ring beam, can be used, for example. Several laser beams can be used, allowing, for instance, heating the fiber from both ends. Using a laser for this step allows for precise and localized control of the heating applied to the areas to be melted and bonded. The laser's optical power can be adjusted according to the size of the areas being treated and / or the amount of material to be melted. Lower power can be used when the areas to be bonded are small, while higher power can be used for a support 10 whose end dimensions correspond to those of the optical fiber 30.

[0069] Alternatively or in combination, the connection between the fiber 30 and the support 10 can be achieved using mechanical alignment means, for example by using a sheath enclosing a piece of the fiber 30 and a piece of the support 10.

[0070] According to one embodiment of the example process described above, it is possible to use a different three-dimensional printing technique for the support 10 than two-photon photopolymerization, in particular a process using single-photon polymerization technology. This may be the case, for example, when very high resolution is not required to produce the shape of this support. According to another embodiment illustrated in the figures 7 to 9 , we can make the waveguide 15 in the support 10 possibly after the annealing step(s) leading to a transformation of the material(s) into glassy material(s).

[0071] Thus, after the annealing(s) leading to the thermal shrinkage of the support 10 and the associated component ( figures 7 And 8 The support 10 is exposed to a laser L, for example the femtosecond laser used previously. This prevents any potential erasure or deterioration of the waveguide 15 created, particularly when the shrinking annealing temperature is too high.

[0072] According to another variant illustrated on the Figures 10 And 11 The waveguide 15 can also be manufactured after the support 10 has been assembled and secured to the optical fiber. Thus, in the example of the embodiment illustrated on the Figure 10A splice is performed between the optical fiber 30 and the support 10, for example using a laser. Then, in this case, when constructing the waveguide 15, care is preferably taken to keep the optical fiber 30 and the support 10 aligned, with the free end 30 preferably kept taut between its ends.

[0073] Besides the possibility of making a waveguide 15 formed in a solid volume of the support 10 and having at least one channel made of a material having a different refractive index than the rest of the support 10, it is possible to make this waveguide 15 as on the figure 12 in the form of a portion 155 surrounded by hollow galleries 154, in other words, empty hollow channels or microstructured empty channels. In either of the embodiments illustrated on the figures 4 , 9 , 11, 12 , 13The waveguide(s) produced have a straight shape. Alternatively, as previously indicated, it is possible to form at least one waveguide of a different shape, for example curved or helical, or to produce in the support 10 one or more straight waveguides as well as at least one waveguide 15 of another shape, for example curved or helical.

[0074] According to another possible embodiment, the support 10 for hosting micro / nano components 21 can be arranged on a wall or a lateral region 30C of a fiber.

[0075] In the example of implementation illustrated on the figure 16 This lateral region 30C is the curved external surface of a fiber 30 in the shape of a cylinder of revolution. It is also possible to arrange such a support 10 on a flat lateral region of a fiber 30 with a "D" shaped cross-section or having a flat area or a substantially flat and locally polished zone.

[0076] In the case where support 10 is assembled on a lateral region of an optical fiber, a laser beam welding process is typically preferred.

[0077] The assembly of the pedestal support 10 equipped with at least one micro- or nano-structured component has been described in the particular case of an optical fiber but can be carried out more generally on an optical waveguide or even another type of structure such as for example a photonic circuit board.

Claims

1. A method for making an optical device provided with a nano-structured or micro-structured component (21) assembled on one end or a lateral surface of a structure (30), in particular an optical guide or an optical fibre, the process comprising the steps of: - providing a carrier (10) based on a first material (12), photosensitive and transformable into a vitreous material, and making on a first end (10A) of said carrier, by multi-photon, in particular two-photon, photopolymerisation, a micro-structured or nano-structured component (21), based on a second material (22) photosensitive and transformable into a vitreous material, - performing one or more heat treatment(s) so as to transform the first material (12) of said carrier and the second material (22) of said micro- or nano-structured component into a vitreous material and then, - assembling and securing a region of a second end (10B) of said carrier (10) opposite to said first end (10A) with an area of one end or a lateral surface of said structure (30).

2. The method according to claim 1, the process further comprising: a step of forming at least one waveguide (15) in a volume of said carrier (10).

3. The method according to claim 2, wherein said at least one waveguide (15) is made in the form of a longitudinal central portion surrounded by longitudinal galleries (154) formed when making said carrier (10) by additive manufacturing.

4. The method according to claim 2, wherein said at least one waveguide (15) is formed after making said component (21) on said carrier (10) and prior to said one or more heat treatment(s).

5. The method according to claim 2, wherein said at least one waveguide (15) is formed after said one or more heat treatment(s).

6. The method according to claim 2, wherein said at least one waveguide (15) is formed after assembling and securing said region of said carrier (10) and said area of said structure (30).

7. The method according to one of claims 4 to 6, wherein said waveguide (15) is made by direct writing by means of a laser in a volume (152) of said carrier (10).

8. The method according to one of claims 2 to 7, wherein several waveguides (15A, 15B, 15C) are formed in said carrier (10).

9. The method according to one of claims 1 to 8, wherein the carrier (10) is made by multi-photon, in particular two-photon, photopolymerisation.

10. The method according to one of claims 1 to 9, wherein said first material (12) is identical to said second material (22).

11. The method according to one of claims 1 to 10, wherein said first material and / or said second material is: - a polymer compound filled with particles of a vitreous material such as silica particles, or - a sol-gel material.

12. The method according to one of claims 1 to 11, wherein the carrier (10) and the micro-structured or nano-structured component (21) are formed in the same step or in successive additive manufacturing steps, an optical objective change being then performed between said successive steps.

13. The method according to one of claims 1 to 12, wherein the component (21) is an optical or photonic component, or a sensor fitted with an optical or photonic component, selected in particular from among the following components: an interferometer, a lens or a lens array, a set of Fresnel lens, a diffractive structure, a mode adapter, a beam combiner, a resonant cavity for optical or acoustic waves.

14. The method according to one of claims 1 to 13, wherein the step of assembling and securing the region of a second end of said carrier (10) with said area is carried out by localised fusion of said region and said area, respectively of said carrier (10) and said structure (30).