PHOTONIC ARRANGEMENT WITH A PHOTONIC ELEMENT OPTICALLY COUPLED TO A PHOTONIC ELEMENT

Description

DOMAINE DE L'INVENTION

[0001] The present invention relates to the field of photonics, and more particularly to an assembly of a photonic device and an external photonic element. Specifically, the present invention relates to the optimization of the optical coupling between the photonic device and the photonic element. ARRIERE PLAN TECHNOLOGIQUE DE L'INVENTION

[0002] The emergence of photonic components in guided optical communications has been accompanied by the development of means and methods for optical coupling between different photonic components or circuits (photonic devices) and other photonic elements such as optical fibers. For example, US patent 9,335,480 B1 (CELO DRITAN [CA]) dated May 10, 2016 (2016-05-10) discloses a method facilitating coupling between a single-mode fiber and a photonic circuit. Specifically, an assembly between a photonic device equipped with a laser source and an external photonic element such as an optical fiber is known.

[0003] For example, the figure 1 and the figure 2 Each illustrates a coupling, known as surface coupling, between a photonic device and an external photonic element. In particular, the figure 1 Figure 1a represents a photonic device equipped with a waveguide 2a, embedded in a substrate 3a. A cavity 4a is formed from a front face 5a of the photonic device 1a. This cavity includes two faces 6a and 7a. In particular, the cavity 4a is formed such that the waveguide 2a opens at one end through face 6a. The photonic device 1a also includes a mirror 8a, resting on face 7a. This arrangement allows the extraction of radiation from the photonic device 1a, for example, radiation emitted by a laser (not shown) and guided by the waveguide 2a. Specifically, radiation exiting through face 6a is reflected by the reflector 8a in a direction outside a plane formed by the front face 5a. The implementation of a lens 10a and a prism 8a allows the extracted radiation to be redirected towards an input of a photonic element 9a which includes, for example, a waveguide or an optical fiber.

[0004] There figure 2 Figure 1b represents another photonic device equipped with a waveguide 2b, embedded in a substrate 3b. The waveguide 2b is terminated at one end by a diffraction grating 4b. In particular, the diffraction grating 4b is configured to project light radiation, for example emitted by a laser (not shown) and guided by the waveguide 2b, towards an output 5b located on a front face 6b of the photonic device 1b. This arrangement thus allows light radiation to be extracted from the front face 6b of the photonic device 1b. The use of a lens 7b and a prism 8b allows the extracted radiation to be redirected towards an input of a photonic element 9b which includes, for example, a waveguide or an optical fiber.

[0005] To continue with the example, the figure 3 This illustrates a coupling method called edge coupling between a photonic device 1c and a photonic element 6c. The photonic device 1c is equipped with a waveguide 2c, embedded in a substrate 3c. The waveguide 2c opens, at one of its ends, onto a lateral face 4c (or edge) of the photonic device 1c. In other words, radiation, emitted for example by a laser (not shown) and guided by the waveguide 2c, is extracted from the photonic device 1c directly through its lateral face 4c. A lens 5c can then be used to couple the extracted radiation to a photonic element 6c, which includes, for example, a waveguide.

[0006] However, there are situations where ensuring unidirectional propagation of light radiation during its extraction from the photonic device is desirable. Indeed, radiation extracted from a photonic device is susceptible to reflection, and thus some of it may be reinjected into the photonic device and ultimately into the laser that produced it. This phenomenon degrades the laser's emission spectrum and, consequently, the performance of the photonic device.

[0007] To overcome this problem, it is generally proposed to implement an optical isolator placed in the path of the extracted radiation between the photonic device and the photonic element to be optically coupled. figure 4 takes, as an example, the device of the figure 3 and in which an optical isolator 7c is interposed between 1a lens 5c and the input of the optical fiber 6c. The optical isolator imposes light propagation in one direction and prevents parasitic reflections that could affect the performance of the photonic device.

[0008] However, this solution has limitations when the photonic device includes, in addition to light extraction, areas, called input zones, through which radiation can be injected into the photonic device. In this respect, the figure 5 Figure 10a illustrates an edge-on optical coupling, viewed from above, of a photonic device 10a with a photonic element 10b. The photonic device 10a may include an array of lasers (not shown, integrated or not) whose radiation is guided by waveguides, referred to as first extraction waveguides 11a. The photonic device 10a also includes waveguides, referred to as first input waveguides 12a, for receiving external light radiation. The photonic element 10b includes second extraction waveguides 12b and second input waveguides 11b optically coupled, respectively, to the first input waveguides 12a and the first extraction waveguides 11a. The photonic component 10b may be a passive component, and may include, for example, an optical fiber array.

[0009] According to this arrangement, light radiation is likely to propagate in two opposite directions. Specifically, a first series of radiation is likely to propagate from the first extraction waveguides 11a to the second inlet waveguides 11b. Equivalently, a second series of radiation is likely to propagate from the second extraction waveguides 12b to the first inlet waveguides 12a.

[0010] Therefore, to optimize coupling performance, the radiation from the first and second series must have approximately equivalent mode sizes. However, implementing an optical isolator to ensure unidirectional propagation along the first series of radiation is not without consequences. Indeed, the optical isolator alters the mode size of the radiation in the first series, so that it no longer has a mode size approximately equivalent to that of the radiation in the second series. In other words, implementing an optical isolator, without other precautions, does not allow for optimal coupling between the first extraction waveguides 11a and the second input waveguides 11b, and between the second extraction waveguides 12b and the first input waveguides 12a.

[0011] One aim of the present invention is therefore to propose an optical coupling between a photonic device and a photonic element and to overcome the aforementioned disadvantages. BREVE DESCRIPTION DE L'INVENTION

[0012] The goal of the invention is achieved by a photonic assembly which comprises: a photonic device comprising a first block having at least one output guide and at least one input guide cooperating with, respectively, at least one first output and at least one first input arranged on a first face of the first block; a photonic element having at least one second output and at least one second input, arranged on a second face of the photonic element, and optically coupled with, respectively, at least one first input and at least one first output; an optical isolator interposed on the path of light propagation, called the first path, between at least one first output and at least one second input, and imposing on radiation, propagating along the first path, a first mode size;adjustment means interposed on the path of light propagation, called the second path, between at least one first input and at least one second output, the adjustment means being configured to impose on a radiation, propagating along the second path, a second mode size equal to the first mode size.

[0013] According to one embodiment, the adjustment means include a blade of thickness Te, and said blade being made of a material of optical index Ne, the thickness Te and the optical index Te being adjusted so that the second mode size is equal to the first mode size.

[0014] According to one embodiment, the optical isolator has an optical index Ni and a thickness Ti, and is combined with a first material of optical index Noi and cumulative thickness Toi interposed on the first path, the blade is combined with a second material of optical index Noe and cumulative thickness Toe interposed on the second path, the optical index Ni, the thickness Ti, the optical index Noi, the cumulative thickness Toi, the optical index Noe, the cumulative thickness Toe, the optical index Ne and the thickness Te respecting the following relationship: Te Ne + Toe Noe = Ti Ni + Toi Noi

[0015] According to one embodiment, the photonic assembly is provided with active alignment means which include a first alignment input, a first alignment output, a second alignment input and a second alignment output chosen from, respectively, at least one first input, at least one first output, at least one second input and at least one second output, the first alignment output and the second alignment input are optically coupled and define in that order a first alignment path, the second alignment output and the first alignment input are optically coupled and define in that order a second alignment path.

[0016] According to one embodiment, the active alignment means are arranged so that light radiation entering the photonic component through the first alignment input exits through the first alignment output, or so that light radiation entering the photonic element through the second alignment input exits through the second alignment output.

[0017] According to one embodiment, the active alignment means comprise an alignment laser and a photodetector arranged in a first arrangement or a second arrangement, the first arrangement allows radiation emitted by the alignment laser, before reaching the photodetector, to take the first alignment path and the second alignment path in order, while the second arrangement allows radiation emitted by the alignment laser, before reaching the photodetector, to take the second alignment path and the first alignment path in order.

[0018] According to one embodiment, the first face and the second face are opposite each other, the optical isolator and the beam adjustment means being interposed, respectively, between the at least one first output and the at least one second input on the one hand, and between the at least one first input and the at least one second output on the other hand.

[0019] According to one implementation method, at least one output guide terminates at one of its ends with at least one first output and at least one input guide terminates at one of its ends with at least one first input.

[0020] According to one implementation method, at least one output guide and at least one input guide extend in a plane parallel to the first face.

[0021] According to one embodiment, at least one output guide terminates at one of its ends with a diffraction grating corresponding to at least one first output, and at least one input guide terminates at one of its ends with another diffraction grating corresponding to at least one first input.

[0022] According to one embodiment, said photonic assembly comprises a prism disposed on the first path and the second path.

[0023] According to one implementation mode, the photonic device includes at least one laser cooperating with at least one output guide.

[0024] According to one embodiment, the photonic element comprises an array of optical fibers resting in grooves of a second block bearing the second face; advantageously, the optical fibers comprise an end flush with the second face.

[0025] According to one embodiment, the photonic device includes lenses resting on the first face and cooperating with at least one first input and at least one first output.

[0026] The invention also relates to a method for forming a photonic assembly which comprises the following steps: a step of supplying a photonic device comprising a first block having at least one output guide and at least one input guide cooperating with, respectively, at least one first output and at least one first input arranged on a first face of the first block; a step of supplying a photonic element having at least one second output and at least one second input, arranged on a second face of the photonic element; a step of arranging an optical isolator interposed on the path of light propagation, called the first path, between the at least one first output and the at least one second input, and imposing on a radiation, propagating along the first path, a first mode size;a step consisting of having adjustment means interposed on the path of light propagation, called the second path, between at least one first input and at least one second output, the adjustment means being configured to impose on a radiation, propagating along the second path, a second mode size equal to the first mode size; the process further comprising an optical coupling step intended to optically couple the at least one second output and the at least one second input with, respectively, the at least one first input and the at least one first output.

[0027] According to one embodiment, the adjustment means include a blade of thickness Te, and said blade being made of a material of optical index Ne, the thickness Te and the optical index Te being adjusted so that the second mode size is equal to the first mode size.

[0028] According to one embodiment, the optical isolator has an optical index Ni and a thickness Ti, and is combined with a first material of optical index Noi and cumulative thickness Toi interposed on the first path, the blade is combined with a second material of optical index Noe and cumulative thickness Toe interposed on the second path, the optical index Ni, the thickness Ti, the optical index Noi, the cumulative thickness Toi, the optical index Noe, the cumulative thickness Toe, the optical index Ne and the thickness Te respecting the following relationship: Te Ne + Toe Noe = Ti Ni + Toi Noi

[0029] According to one embodiment, the optical coupling step implements active alignment means, the active alignment means include a first alignment input, a first alignment output, a second alignment input and a second alignment output chosen from, respectively, at least one first input, at least one first output, at least one second input and at least one second output, the first alignment output and the second alignment input are optically coupled and define in that order a first alignment path, the second alignment output and the first alignment input are optically coupled and define in that order a second alignment path, the optical coupling step includes the emission of light radiation which, when it takes one of the first or second alignment paths, then takes the other of the first or second alignment paths.

[0030] According to one embodiment, the active alignment means are arranged so that light radiation entering the photonic device through the first alignment input exits through the first alignment output, or so that light radiation entering the photonic element through the second alignment input exits through the second alignment output.

[0031] According to one embodiment, the optical coupling step includes the emission of light radiation by an alignment laser and the detection of said radiation by a photodetector, the alignment laser and the photodetector being arranged according to a first arrangement or a second arrangement, the first arrangement allows radiation emitted by the alignment laser, before reaching the photodetector, to take the first alignment path and the second alignment path in order, while the second arrangement allows radiation emitted by the alignment laser, before reaching the photodetector, to take the second alignment path and the first alignment path in order. BREVE DESCRIPTION DES DESSINS

[0032] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the attached figures in which: [ Fig.1 ] There figure 1 is a schematic representation of a photonic device, according to a cross-sectional plane of said device, known from the prior art, and illustrating a mode of optical coupling via the surface with a photonic element not shown; Fig.2 ] There figure 2 is a schematic representation of another photonic device, according to a cross-sectional plane of said device, known from the prior art, and illustrating a mode of optical coupling via the surface with another photonic element; [ Fig.3 ] There figure 3 is a schematic representation of another photonic device, according to a cross-sectional plane of said device, known from the prior art, and illustrating a coupling mode by the edge; [ Fig.4 ] There figure 4 is illustrated by the implementation of an optical isolator for coupling between the photonic device and the photonic element shown in the figure 3 ; Fig.5 ] There figure 5 is a schematic representation of an assembly of a first photonic component and a second photonic component optically coupled to each other; [ Fig.6 ] There figure 6 is a schematic representation of a photonic assembly according to a first embodiment of the present invention, in particular the photonic assembly is represented according to a cutting plane perpendicular to the first and second faces, and which includes all the guides of the photonic device and the photonic element; [ Fig.7 ] There figure 7 is a schematic representation of the photonic device of the figure 6 and represented according to the same modalities of the figure 6 ; Fig.8 ] There figure 8 is a schematic representation of the photonic element of the figure 6 and represented according to the same modalities of the figure 6 ; Fig.9 ] There figure 9 is a schematic representation of a photonic assembly of the figure 6 and to which are added means for active alignment according to a first variant of the first embodiment of the present invention; [ Fig.10 ] There figure 10 is a schematic representation of the photonic device of the figure 9 and represented according to the same modalities of the figure 9 ; Fig.11 ] There figure 11 is a schematic representation of the photonic element of the figure 9 and represented according to the same modalities of the figure 9 ; Fig.12 ] There figure 12 is a schematic representation of a photonic assembly of the figure 6 and to which are added active alignment means according to a second variant of the first embodiment of the present invention; [ Fig.13 ] There figure 13 is a schematic representation of the photonic device of the figure 12 and represented according to the same modalities of the figure 12 ; Fig.14 ] There figure 14 is a schematic representation of the photonic element of the figure 12 and represented according to the same modalities of the figure 12 ; Fig.15 ] There figure 15 a schematic representation of a photonic device capable of being implemented in a second embodiment of the present invention, in particular the photonic device is represented according to a cross-sectional plane parallel to the first face and which includes the waveguides of said photonic device; Fig.16 ] There figure 16 is a representation of a photonic assembly according to the second embodiment of the present invention, in particular the photonic assembly is represented according to a torque plane perpendicular to the first face and which includes an output guide; [ Fig.17 ] There figure 17 is a representation of a photonic assembly according to the second embodiment of the present invention, in particular the photonic assembly is represented according to a couple plane perpendicular to the first face and which includes an input guide. DESCRIPTION DETAILLEE DE L'INVENTION

[0033] The invention relates to a photonic assembly provided with a photonic device and a photonic element optically coupled to each other.

[0034] In particular, the photonic device includes a first block provided with at least one output guide and at least one input guide cooperating with, respectively, at least one first output and at least one first input arranged on a first face of the block.

[0035] The photonic element is provided with at least one second output and at least one second input, arranged on a second face of the photonic element. In this respect, the at least one second output and the at least one second input are optically coupled with, respectively, the at least one first input and the at least one first output.

[0036] The photonic assembly also includes an optical isolator placed in the path of light propagation, called the first path, between at least one first output and at least one second input. Furthermore, the optical isolator imposes a first mode size (or "Waist" in Anglo-Saxon terminology) on radiation propagating along the first path.

[0037] The photonic assembly also includes adjustment means interposed along the light propagation path, called the second path, between at least one first input and at least one second output. In this respect, the adjustment means are configured to impose on radiation propagating along the second path a second mode size equal to the first mode size.

[0038] By "optically coupled," we mean an input and an output arranged such that light emanating from the output is injected into the input. For the purposes of this invention, an input is an optical input, and an output is an optical output. In other words, light emanating from an optical input will be injected into the component (device or element) under consideration. Equivalently, light emanating from an optical output can be extracted from the component (device or element) under consideration.

[0039] According to the present invention, a waveguide is a waveguide. Furthermore, when a waveguide interacts with an output within a photonic device, radiation guided by said waveguide can be extracted from the photonic device through the output. Equivalently, when a waveguide interacts with an input within a photonic device, radiation injected into the photonic device through the input will be guided by said waveguide.

[0040] As described later in the statement, the cooperation between a waveguide and an output or input can be reduced to simply identifying one end of the waveguide with the input or output. Alternatively, this cooperation between a waveguide and an input or output can involve a diffraction grating.

[0041] Thus, the figure 6 represents a photonic assembly 100 according to a first embodiment of the present invention and associated with edge coupling. In particular, the photonic assembly 100 comprises a photonic device 200a and a photonic element 200b.

[0042] The 200a photonic device comprises, in this respect, a first block 200a1. As illustrated in the figure 7 , the first block 200a1 includes a face called first face 201a on which are formed or arranged at least one first output 202a and at least one first input 203a.

[0043] The photonic device may also include lenses 210 resting on the first face 201a and cooperating with at least one first input 203a and at least one first output 202a. More specifically, each first output 202a is associated with its own lens, such that light ray extracted by said first output passes through the lens in question. Equivalently, each first input 203a is associated with its own lens, such that light ray, before being injected by said first input, passes through the lens in question.

[0044] The first block 200a1 also includes waveguides, and more specifically at least one output waveguide 207a and at least one input waveguide 208a. In particular, at least one output waveguide 207a cooperates with at least one first output waveguide 202a, while at least one input waveguide 208a cooperates with at least one first input waveguide 208a.

[0045] Thus, light beams guided by at least one output guide 207a can be extracted from the first block 200a1 by at least one first output 202a with which it cooperates. Equivalently, light beams injected into the first block 200a1 by at least one first input 208a will be guided by at least one input guide 208a.

[0046] The light radiation capable of being guided by at least one output guide 207a comes from one or more light sources, for example one or more lasers, or even a laser array.

[0047] One or more light sources can be integrated into the 200a photonic device, or even into the first 200a1 block, or simply be external to said 200a photonic device.

[0048] As an example, the 200a photonic device of the figure 6 It comprises three output guides 202a and a laser array 270 integrated into the first block 200a1. Specifically, each laser 270 is associated with an output guide 202a such that light emitted by that laser is guided by the output guide with which it is associated. However, the invention is not limited to this arrangement alone, and those skilled in the art may consider any other configuration in terms of integration and number of lasers.

[0049] It is noteworthy that radiation emitted by a laser source is polarized along a preferred direction. Thus, and without needing to specify it, the 200a photonic device is configured to allow the propagation and / or guidance of light radiation (laser) polarized along a predetermined direction.

[0050] According to this first embodiment, at least one exit guide 207a terminates at one end with at least one first exit 202a, while at least one inlet guide 208a terminates at one end with at least one first inlet 203a. In other words, the end of at least one exit guide 207a forming at least one first exit 202a is flush with the first face 201a. Equivalently, the end of at least one inlet guide 208a forming at least one first inlet 203a is flush with the first face 201a.

[0051] According to the present invention, the waveguides of the first block 200a1 may comprise silicon nitride or silicon embedded in a silicon oxide matrix.

[0052] The photonic assembly 100 also includes a photonic element 200b ( figure 6 And figure 8 The photonic element 200b, like the first block 200a1, comprises a second face 201b on which at least one second output 203b and at least one second input 202b are formed. According to the present invention, the photonic element 200b and the photonic device 200a are arranged such that the at least one second output 203b and the at least one second input 202b are optically coupled with, respectively, the at least one first input 203a and the at least one first output 202a.

[0053] Thus, light radiation extracted from the photonic device 200a by at least one first output 202a will be injected into the photonic element 200b by at least one second input 202b. Equivalently, light radiation extracted from the photonic element 200b by at least one second output 203b will be injected into the photonic device 200a by at least one first input 203a.

[0054] To this end, and according to the first embodiment, the first face 201a and the second face 201b are opposite each other. More specifically, the first face 201a and the second face 201b are separated by a distance D.

[0055] The photonic element 200b according to the present invention may comprise an optical fiber network, and more particularly at least one input fiber 207b and at least one output fiber 208b. In particular, the at least one input fiber 207b cooperates with the at least one second input 202b ( figure 8 ). Equivalently, at least one 208b output fiber cooperates with at least one second 203b output.

[0056] For example, at least one input fiber 207b terminates at one end with at least one second input 202b, while at least one output fiber 208b terminates at one end with at least one second output 203b. In other words, the end of at least one input fiber 207b forming at least one second input 202b and the end of at least one output fiber 208b forming at least one second output 203b are flush with the second face 201b. According to this configuration, the second face can be supported by a second block 200b1 provided with grooves (V-grooves in Anglo-Saxon terminology), in which the optical fibers are mounted.

[0057] The photonic assembly 100 also includes an optical isolator 250 interposed in the path of light propagation, referred to as the first path, between at least one first output 202a and at least one second input 202b. It is clear, however, without needing to be explicitly stated, that the optical isolator 250 does not interpose itself between at least one second output 203b and at least one first input 203a. The optical isolator 250 has, in particular, an optical index Ni and a thickness Ti measured along the direction defined by the first path.

[0058] The optical insulator can, for example, be glued to either of the first and second faces. According to this first embodiment, the optical insulator is glued to the second face.

[0059] The optical insulator 250 can be combined with a first material of refractive index Noi and cumulative thickness Toi interposed in the first path. In other words, radiation traveling along the first path will pass through the optical insulator 250 and a thickness Toi of the first material. For example, the first material can fill the gap between the optical insulator 250 and the first and / or second face. The first material can be air or a dielectric material.

[0060] The "first path" defines a direction of propagation of the light radiation from at least one first output 202a to at least one second input 202b.

[0061] An optical isolator 250 according to the terms of the present invention is an optical component allowing the propagation of light in one direction. Such a component may in particular include a Faraday rotator interposed between a first polarizer and a second polarizer whose optical axis is offset by 45° with respect to that of the polarizer.

[0062] Thus, only one component, called the useful component of radiation, oriented along the optical axis of the first polarizer, is transmitted by the latter to the Faraday rotator. As it passes through the Faraday rotator, the polarization of the useful component undergoes a 45° rotation before reaching the second polarizer. The useful component, having a polarization parallel to the optical axis of the polarizer, is then transmitted by the latter to form the output radiation. It is therefore understood that input radiation with a polarization perpendicular to the optical axis of the polarizer will not be transmitted by the optical isolator. It is also understood that radiation incident on the second polarizer, regardless of its polarization, will not be transmitted by the optical isolator. This latter aspect, well known to those skilled in the art, originates from the non-reciprocal nature of the Faraday rotator.

[0063] The optical isolator 250 is arranged to allow the propagation of light from at least one first output 202a to at least one second input 202b along the first path. The implementation of the optical isolator 250 eliminates unwanted reflections that light might otherwise experience along the first path. Eliminating these unwanted reflections prevents any return of the light to the laser(s), thus limiting the degradation of their performance.

[0064] The implementation of the optical isolator 250 imposes on a light ray, propagating along the first path, a first mode size ("Waist" according to Anglo-Saxon terminology). Therefore, the distance D between the first face 201a and the second face 201b is generally adjusted to account for this phenomenon and thus optimize the optical coupling between at least one first output 202a and at least one second input 202b.

[0065] This adjustment, however, has consequences for the efficiency or optimization of the coupling between the at least one second output 203b and the at least one first input 202a. In particular, and without further precautions, light radiation propagating along a second path from the at least one second output 203b to the at least one first input 203a will not be subjected to the first mode size.

[0066] Thus, to overcome this problem, it is proposed to implement adjustment means 260 placed in the path of light propagation, between at least one first input 203a and at least one second output 203b. The adjustment means 260 are specifically configured to impose on radiation propagating along the second path a second mode size substantially equal to the first mode size. It is clear, without needing to be explicitly stated, that the adjustment means 260 are not placed between at least one first output 202a and at least one second input 202b.

[0067] Implementing a second optical isolator as a means of adjustment, oriented to allow light to pass from at least one second output to at least one first input, is undesirable. This is because the polarization of radiation guided by a fiber of the photonic element is unknown, meaning that this radiation could be partially transmitted, or even blocked, if an optical isolator were to be implemented as an adjustment means. Simply implementing a second optical isolator would block all or part of the signal.

[0068] For example, the adjustment means 260 may include a blade of thickness Te, and said blade being made of a material of optical index Ne. The thickness Te and the optical index Te being adjusted so that the second mode size is substantially equal to the first mode size (It is understood that the thickness Te is measured along a direction defined by the faces of the blade parallel to the first and second face).

[0069] The blade can, for example, be glued to either of the first and second faces. According to this first embodiment, the blade is glued to the second face.

[0070] The adjustment may include, in particular, the consideration of an optical index Ne, advantageously greater than the optical index Ni. This configuration is particularly advantageous insofar as it allows spacing (increasing the distance "D") between the first and second faces, and consequently facilitates the assembly process of the photonic device and the photonic element.

[0071] Alternatively or complementarily, the 260 plate can be combined with a second material of index Noe and cumulative thickness Toe interposed in the second path. In other words, radiation traveling along the second path will pass through the 260 plate and a thickness Toe of the second material. For example, the second material can fill the gap between the 260 plate and the first and / or second face. The second material can be air or a dielectric material.

[0072] According to this alternative, the adjustment can be performed by imposing the following relationship on the quantities Te, Ne, Toe, Noe, Ti, Ni, Toi and Noi: Te Ne + Toe Noe = Ti Ni + Toi Noi

[0073] According to a first variant of this first embodiment illustrated in the figure 9 , to the figure 10 and to the figure 11 The photonic assembly 100 is provided with active alignment means. By "active alignment means", we mean means configured to optimize the optical coupling between the via a first output 202a and at least a second input 202b on the one hand, and between at least a second output 203b and at least a first input 203a on the other hand.

[0074] In particular, the active alignment means include a first alignment input 205a, a first alignment output 204a, a second alignment input 204b, and a second alignment output 205b selected from, respectively, at least one first input 203a, at least one first output 202a, at least one second input 202b, and at least one second output 203b. In particular, the first alignment output 204a and the second alignment input 204b are optically coupled and define, in that order, a first alignment path; the second alignment output 205b and the first alignment input 205a are optically coupled and define, in that order, a second alignment path.

[0075] According to this first variant, the active alignment means are arranged so that light radiation entering the photonic device 200a through the first alignment input 205a exits through the first alignment output 204a.

[0076] To this end, the active alignment means may also include an alignment output guide 301a and an alignment input guide 302a selected from, respectively, at least one output guide 207a and at least one input guide 208a. In particular, the alignment output guide 301a and the alignment input guide 302a each have one end flush with the first face 201a and form, respectively, the first alignment output 204a and the first alignment input 205a. Furthermore, the alignment output guide 301a and the alignment input guide 302a are optically linked to each other at their other ends, in particular by means of a waveguide, referred to as the linking waveguide 303.

[0077] The active alignment means may include a 301b alignment input fiber and a 302b alignment output fiber selected from, respectively, at least one 207b input fiber and at least one 208b output fiber.

[0078] The active alignment means may also include an alignment laser 300 and a photodetector 400. Notably, the alignment laser 300 can be arranged to inject light radiation at one end of the alignment output fiber 302b opposite the second alignment output 205b.

[0079] Equivalently, the 400 photodetector can be arranged to detect light radiation guided by the alignment input fiber 302b at one end, called the detection end, opposite the second alignment input 204b.

[0080] Thus, light emitted by the alignment laser 300 will be transmitted from the second alignment output 205b to the photonic device 200a via its first alignment input 205a and exit through the first alignment output 204a. The light will then be retransmitted to the photonic element via the second alignment input 204b to be detected at the detection end by the photodetector 400.

[0081] This arrangement is particularly advantageous when it comes to precisely aligning the photonic device and the photonic element optically. Specifically, optical alignment can include optimizing, and more particularly maximizing, the intensity of the light radiation detected by the 400 photodetector.

[0082] There figure 12 , there figure 13 and the figure 14 illustrate a second implementation variant of the active alignment means. This second variant essentially retains the characteristics of the first variant. However, the second variant differs from the first variant in that the active alignment means are arranged so that light entering the photonic component 200a through the second alignment input 204b exits through the second alignment output 205b, and lacks the linking waveguide 303. Also, according to this second variant, the alignment laser 300 and the photodetector 400 are arranged to cooperate with, respectively, the alignment output guide 301a and the alignment input guide 302a. In particular, the alignment laser 300 can be arranged to inject light at one end of the alignment output guide 301a opposite the first alignment output 204a.Also, the 400 photodetector can be arranged to detect light radiation guided by the alignment input guide 302a at one end, called the detection end, opposite the first alignment input 205a.

[0083] Finally, according to this second variant, the 301b alignment input fiber and the 302b alignment output fiber are optically linked at one of their ends, opposite the second alignment input and second alignment output, respectively. This optical link utilizes, in particular, an optical fiber, referred to as the 304 link optical fiber.

[0084] The invention also relates to a second embodiment which essentially reproduces the elements of the first embodiment. According to this second embodiment, however, the optical coupling between the photonic device and the photonic element is performed by the surface ( figure 15, figure 16 And figure 17 ).

[0085] Thus, and contrary to the arrangement proposed in the first embodiment, the at least one first output 202a and the at least one first input 203a do not form the ends, respectively, of the at least one output guide 207a and the at least one input guide 208a.

[0086] According to the second embodiment, at least one output guide 207a and at least one input guide 208a extend along a plane parallel to the first face 201a. The photonic device 200a also includes diffraction gratings, and more particularly at least one output grating 211a and at least one input grating 212a extending, respectively, from at least one output guide 207a and at least one input guide 208a.

[0087] More specifically, at least one output array 211a corresponds to at least one first output 202a. Thus, radiation guided by at least one output guide 207a will be projected towards at least one first output 202a for extraction by said at least one first output 202a ( figure 16 ).

[0088] Equivalently, at least one input grating 212a corresponds to at least one first input 203a. Thus, radiation injected by at least one first input 203a will be projected onto at least one input grating 212a and then guided by at least one input guide 208a ( figure 17 ).

[0089] Similar to the first embodiment, the photonic assembly 100 according to the second embodiment may include lenses 210. The lenses rest on the first face 201a and cooperate with at least one first entrance 203a ( figure 17 ) and at least one first exit 202a ( figure 16 In particular, each first output 202a is associated with its own lens, so that light emitted by said first output passes through that lens. Similarly, each first input 203a is associated with its own lens, so that light emitted by said first input passes through that lens before being injected.

[0090] The photonic assembly 100 may also include a prism 213 disposed on the first path and the second path intended to allow optical coupling between the at least first output with the at least one second input on the one hand, and between the at least one second output with the at least one first input on the other hand.

[0091] The implementation of the blade within the photonic assembly according to the terms of the present invention thus makes it possible to optimize the coupling between at least one second output and at least one first input when an optical isolator is interposed on the first path.

[0092] Of course, the invention is not limited to the embodiments described and alternative embodiments can be made without departing from the scope of the invention as defined by the claims.

Claims

1. Photonic assembly (100) which comprises: - a photonic device (200a) comprising a first block (200a1) equipped with at least one output guide (207a) and at least one input guide (208a) cooperating respectively with at least one first output (202a) and at least one first input (203a) which are disposed on a first face (201a) of the first block (200a1); - a photonic element (200b) equipped with at least one second output (203b) and at least one second input (202b) which are disposed on a second face (201b) of the photonic element and are optically coupled respectively with the at least one first input (203a) and the at least one first output (202a); - an optical isolator (250) interposing in the light propagation path, referred to as the first path, between the at least one first output (202a) and the at least one second input (202b) and imposing a first mode size on a beam propagating along the first path; - adjustment means (260) interposing in the light propagation path, referred to as the second path, between the at least one first input (203a) and the at least one second output (203b), the adjustment means (260) being configured to impose a second mode size equal to the first mode size on a beam propagating along the second path, the adjustment means (260) comprise a plate of thickness Te, and said plate being made of a material of optical index Ne, the thickness Te and the optical index Te being adjusted so that the second mode size is equal to the first mode size.

2. Photonic assembly (100) according to claim 1, wherein the optical isolator (250) has an optical index Ni and a thickness Ti and is combined with a first material, of optical index Noi and of cumulative thickness Toi, interposing in the first path, the plate is combined with a second material, of optical index Noe and of cumulative thickness Toe, interposing in the second path, the optical index Ni, the thickness Ti, the optical index Noi, the cumulative thickness Toi, the optical index Noe, the cumulative thickness Toe, the optical index Ne and the thickness Te satisfying the following relationship: Te Ne + Toe Noe = Ti Ni + Toi Noi 3. Photonic assembly (100) according to either of claims 1 and 2, wherein the photonic assembly (100) is equipped with active-alignment means which comprise a first alignment input (205a), a first alignment output (204a), a second alignment input (204b) and a second alignment output (205b) which are selected respectively from the at least one first input (203a), the at least one first output (202a), the at least one second input (202b) and the at least one second output (203b), the first alignment output (204a) and the second alignment input (204b) are optically coupled and in this order define a first alignment path, the second alignment output (205b) and the first alignment input (205a) are optically coupled and in this order define a second alignment path.

4. Photonic assembly (100) according to claim 3, wherein the active-alignment means are arranged such that a light beam entering the photonic device (200a) via the first alignment input (205a) exits therefrom via the first alignment output (204a) or such that a light beam entering the photonic element (200b) via the second alignment input (204b) exits therefrom via the second alignment output (205b).

5. Photonic assembly (100) according to claim 4, wherein the active-alignment means comprise an alignment laser (300) and a photodetector (400) which are arranged according to a first arrangement or a second arrangement, the first arrangement allows a beam emitted by the alignment laser (300), before reaching the photodetector (400), to follow the first alignment path and then the second alignment path, while the second arrangement allows a beam emitted by the alignment laser (300), before reaching the photodetector (400), to imprint the second alignment path and then the first alignment path.

6. Photonic assembly (100) according to any of claims 1 to 5, wherein the first face (201a) and the second face (201b) face one another, the optical isolator (250) and the beam adjustment means (260) being positioned respectively between the at least one first output (202a) and the at least one second input (202b) and between the at least one first input (203a) and the at least one second output (203b).

7. Photonic assembly (100) according to any of claims 1 to 6, wherein the at least one output guide (207a) terminates at one of the ends thereof in the at least one first output (202a), and the at least one input guide (208a) terminates at one of the ends thereof in the at least one first input (203a).

8. Photonic assembly (100) according to any of claims 1 to 5, wherein the at least one output guide (207a) and at least one input guide (208a) extend in a plane parallel to the first face (201a).

9. Photonic assembly (100) according to claim 8, wherein the at least one output guide (207a) terminates at one of its ends in a diffraction grating communicating with the at least one first output (202a), and the at least one input guide (208a) terminates at one of its ends in another diffraction grating communicating with the at least one first input (203a).

10. Photonic assembly (100) according to claim 8 or 9, wherein said photonic assembly (100) comprises a prism disposed in the first path and the second path.

11. Photonic assembly (100) according to any of claims 5 to 10, wherein the photonic device (200a) comprises at least one laser cooperating with the at least one output guide (207a).

12. Photonic assembly (100) according to any of claims 1 to 11, wherein the photonic element (200b) comprises an array of optical fibers which are mounted in grooves in a second block bearing the second face (201b), the optical fibers advantageously comprise an end flush with the second face.

13. Photonic assembly (100) according to any of claims 1 to 12, wherein the photonic device comprises lenses resting on the first face and cooperating with the at least one first input (203a) and the at least one first output (202a).

14. Method for forming a photonic assembly (100), which method comprises the following steps: - a step of providing a photonic device (200a) comprising a first block (200a1) equipped with at least one output guide (207a) and at least one input guide (208a) cooperating respectively with at least one first output (202a) and at least one first input (203a) which are disposed on a first face (201a) of the first block (200a); - a step of providing a photonic element (200b) equipped with at least one second output (203b) and at least one second input (202b) which are disposed on a second face (201b) of the photonic element; - a step consisting in disposing an optical isolator (250) interposing in the light propagation path, referred to as the first path, between the at least one first output (202a) and the at least one second input (202b) and imposing a first mode size on a beam propagating along the first path; - a step consisting in disposing adjustment means (260) interposing in the light propagation path, referred to as the second path, between the at least one first input (203a) and the at least one second output (203b), the adjustment means (260) being configured to impose a second mode size equal to the first mode size on a beam propagating along the second path; the method further comprising an optical coupling step for optically coupling the at least one second output (203b) and the at least one second input (202b) respectively with the at least one first input (203a) and the at least one first output (202a), the adjustment means (260) comprise a plate of thickness Te, and said plate being made of a material of optical index Ne, the thickness Te and the optical index Te being adjusted so that the second mode size is equal to the first mode size.

15. Method according to claim 14, wherein the optical isolator (250) has an optical index Ni and a thickness Ti and is combined with a first material, of optical index Noi and of cumulative thickness Toi, interposing in the first path, the plate is combined with a second material, of optical index Noe and of cumulative thickness Toe, interposing in the second path, the optical index Ni, the thickness Ti, the optical index Noi, the cumulative thickness Toi, the optical index Noe, the cumulative thickness Toe, the optical index Ne and the thickness Te satisfying the following relationship: Te Ne + Toe Noe = Ti Ni + Toi Noi 16. Method according to either of claims 14 and 15, wherein the optical coupling step implements active-alignment means, the active-alignment means comprise a first alignment input (205a), a first alignment output (204a), a second alignment input (204b) and a second alignment output (205b) which are selected respectively from the at least one first input (203a), the at least one first output (202a), the at least one second input (202b) and the at least one second output (203b), the first alignment output (204a) and the second alignment input (204b) are optically coupled and in this order define a first alignment path, the second alignment output (205b) and the first alignment input (205a) are optically coupled and in this order define a second alignment path, the optical coupling step comprising the emission of a light beam which, on following one of the first and the second alignment path, then follows the other of the first and the second alignment path.

17. Method according to claim 16, wherein the active-alignment means are arranged such that a light beam entering the photonic device (200a) via the first alignment input (205a) exits therefrom via the first alignment output (204a) or such that a light beam entering the photonic element (200b) via the second alignment input (204b) exits therefrom via the second alignment output (205b).

18. Method according to claim 17, wherein the optical coupling step comprises an alignment laser (300) emitting a light beam and a photodetector (400) detecting said beam, the alignment laser (300) and the photodetector being arranged according to a first arrangement or a second arrangement, the first arrangement allows a beam emitted by the alignment laser (300), before reaching the photodetector (400), to follow the first alignment path and then the second alignment path, while the second arrangement allows a beam emitted by the alignment laser (300), before reaching the photodetector (400), to follow the second alignment path and then the first alignment path.