Photonic chip equipped with one or two Mach Zehnder modulators

Abstract

The invention relates to a photonic chip (10) comprising: - a waveguide layer; - one or two Mach-Zehnder modulators (100) formed on and / or in the waveguide layer, comprising a first branch (101) and a second branch (102), the branches being arranged between an optical input (112) and an optical output (113), such that light injected at the optical input (112) is split into a first and a second beam, which are then recombined at the optical output (113), each modulation branch being configured to modulate the phase of a light beam; the optical chip comprises at least two optical amplifiers made of semiconductor materials (114, 115) arranged to separately amplify the first and second beams before their recombination at the optical output (113). Figure 4

Description

Title of the invention: PHOTONIC CHIP EQUIPPED WITH ONE OR TWO MACH ZEHNDER MODULATORS FIELD OF INVENTION

[0001] The present invention relates to the field of photonics and more particularly to integrated photonic chips.

[0002] In particular, the invention relates to a photonic chip equipped with a Mach Zehnder modulator and for which the insertion losses are compensated by two optical amplifiers with semiconductor materials.

[0003] According to the present invention, optical amplifiers made of semiconductor materials are arranged in such a way as to limit the negative effects related to the amplification of an intensity-modulated optical signal. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0004] Figure 1 represents a Mach Zehnder device 1 known from the prior art. The Mach Zehnder device 1 includes in particular two modulation branches, referred to as first branch 2 and second branch 3, connected at one end by an optical input 4 and at the other end by an optical output 5.

[0005] In particular, the two modulation branches 2 and 3 are arranged so that a light radiation injected at the optical input 4 is divided into a first radiation and a second radiation guided, respectively, by the first branch 2 and the second branch 3, and so that said first radiation and said second radiation are recombined at the optical output.

[0006] The device is also provided with two phase modulators, called first modulator 6 and second modulator 7, intended to impose a phase shift, respectively, on the first and second radiations before their recombination at the optical output 5. Modifying the phase of one and / or the other of the first and second radiations allows, in particular, the modulation of the intensity of the recombined radiation at the output of the Mach Zehnder device.

[0007] Nevertheless, such a Mach Zehnder 1 device is subject to losses, and more particularly to losses related to the losses of the phase modulators 6 and 7, which reduce its performance.

[0008] Therefore, in order to overcome this problem, it is considered to add a semiconductor optical amplifier (or "SOA" in Anglo-Saxon terminology) to the Mach-Zehnder device in order to amplify the recombined radiation. In this regard, document [1] cited at the end of the description discloses a Mach Zehnder device equipped with a semiconductor optical amplifier disposed downstream of the optical output 5 of said device.

[0009] However, this arrangement is not satisfactory. Indeed, as indicated in document [2] cited at the end of the description, the optical gain G of a semiconductor optical amplifier is not linear. More specifically, the optical gain G decreases as the optical power injected into the input of said amplifier increases, such that the power delivered at the output of the semiconductor optical amplifier cannot exceed a saturation power. This nonlinear behavior thus gives rise to distortions of the intensity-modulated signal amplified by the SOA.Furthermore, due to the 'amplitude / phase' coupling effect, known and quantified by those skilled in the art using the 'Henry factor' in III-V SOA semiconductor components or lasers, strong variations in optical intensity give rise to phase variations, and consequently, also alter an intensity and phase modulated signal, by also distorting the phase modulation.

[0010] Thus, one object of the present invention is to propose a photonic chip provided with at least one Mach Zehnder modulator whose optical signal can be amplified without imposing distortion of the modulated signal. BRIEF DESCRIPTION OF THE INVENTION

[0011] The object of the invention is achieved by a photonic chip comprising:

[0012] - a support substrate provided with a front face;

[0013] - a waveguide layer resting on the front face;

[0014] - one or two Mach Zehnder modulators formed on and / or in the guide layer wave, each comprising two modulation branches, called first branch and second branch, the modulation branches being arranged between an optical input and an optical output, so that a light radiation injected at the optical input is divided into a first radiation and a second radiation intended to be guided by the Mach Zehnder modulator(s), and are then recombined at the optical output, each modulation branch being configured to modulate the phase of a light radiation that said modulation branch is capable of guiding;

[0015] the optical chip being remarkable in that it comprises at least two optical amplifiers of semiconductor materials arranged to separately amplify the first and second radiations before their recombination at the optical output.

[0016] According to one embodiment, each of the two modulation branches comprises a modulation section formed by a waveguide, referred to as a modulation waveguide, and a modulation element, advantageously the modulation element comprising at least one electrode, the modulation element being configured to modulate the phase of a radiation that can be guided by the modulation waveguide, the second branch also comprising a phase-shifting module configured to impose a fixed phase shift on a light radiation that can be guided by said second branch.

[0017] According to one embodiment, the Mach Zehnder modulator(s) comprises a single Mach Zehnder modulator, the first branch and the second branch of the single Mach Zehnder modulator being connected, at one of their ends, by the optical input and, at the other of their ends, by the optical output so that the first radiation and the second radiation are guided, respectively, by the first branch and by the second branch.

[0018] According to one embodiment, the at least two optical amplifiers of semiconductor materials comprise a first amplifier and a second amplifier disposed respectively on the first branch and on the second branch, the first amplifier and the second amplifier being configured to amplify, respectively, the first radiation and the second radiation.

[0019] According to one embodiment, the semiconductor material amplifier of a modulation branch is arranged downstream of the modulation section of the modulation branch considered.

[0020] According to one embodiment, the semiconductor material amplifier of a modulation branch is arranged upstream of the modulation section of the modulation branch considered.

[0021] According to one embodiment, the Mach Zehnder modulator(s) comprise two Mach Zehnder modulators, respectively called modulator I and modulator Q, such that the photonic chip forms a modulator IQ, the first branch and the second branch of modulator I being connected, at one of their ends, by an intermediate optical input called input I, and, at the other of their ends, by an intermediate optical output called output I, the first branch and the second branch of modulator Q being connected, at one of their ends, by another intermediate optical input called input Q, and, at the other of their ends, by another intermediate optical output called output Q.

[0022] According to one embodiment, said photonic chip comprises a radiation splitter and a radiation combiner, the radiation splitter comprising two waveguides, respectively called input guide I and input guide Q, the input guide I and the input guide Q connecting the optical input with, respectively, input I and input Q, such that the first and second radiations are injected at, respectively, input I and input Q, the radiation combiner comprising two waveguides, respectively called output guide I and output guide Q, output guide I and output guide Q connecting the optical output with, respectively, output I and output Q.

[0023] According to one embodiment, the at least two optical amplifiers of semiconductor materials comprise a first amplifier I, a second amplifier I, a first amplifier Q and a second amplifier Q, the first amplifier I, the second amplifier I are arranged respectively on the first branch and on the second branch of the modulator I, while the first amplifier Q and the second amplifier Q are arranged respectively on the first branch and on the second branch of the modulator Q.

[0024] According to one embodiment, the optical amplifier made of semiconductor materials of a modulation branch of a Mach Zehnder modulator is arranged between the modulation section of the modulation branch considered and the intermediate optical output of said Mach Zehnder modulator.

[0025] According to one embodiment, the optical amplifier made of semiconductor materials of a modulation branch of a Mach Zehnder modulator is disposed between the modulation section of the modulation branch considered and the intermediate optical input of said Mach Zehnder modulator.

[0026] According to one embodiment, the at least two optical amplifiers of semiconductor materials comprise an amplifier I and an amplifier Q carried, respectively, by the output guide I and the output guide Q.

[0027] According to one embodiment, said photonic chip further comprises another phase-shifting module configured to impose another fixed phase shift on a light beam between the Q output and the optical output.

[0028] According to one embodiment, the modulation waveguide comprises silicon, advantageously doped silicon, even more advantageously a PN junction along the silicon waveguide.

[0029] According to one embodiment, the at least two optical amplifiers made of semiconductor materials comprise a waveguide made of III-V semiconductor materials. Brief description of the drawings

[0030] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the accompanying figures in which:

[0031] [Fig.1] The [Fig.1] is a schematic representation of a Mach Zehnder 1 device known from the prior art;

[0032] [Fig.2] Fig.2 is a schematic representation of a Mach Zehnder device capable of being implemented within the framework of the present invention;

[0033] [Fig.3] The [Fig.3] is a schematic representation of a support substrate on one face of which the waveguide layer rests, and according to a cutting plane perpendicular to the front face;

[0034] [Fig.4] The [Fig.4] is a schematic representation of a photonic chip according to a first variant of a first embodiment of the present invention, the photonic chip according to this first embodiment includes in particular a single Mach Zehnder modulator and two optical amplifiers with semiconductor materials;

[0035] [Fig.5] The [Fig.5] is a schematic representation of a photonic chip according to a second variant of the first embodiment of the present invention, the photonic chip according to this first embodiment includes in particular a single Mach Zehnder modulator and two optical amplifiers with semiconductor materials;

[0036] [Fig.6] The [Fig.6] is a schematic representation of a photonic chip according to a first variant of a second embodiment of the present invention, the photonic chip according to this second embodiment includes in particular two Mach Zehnder modulators and four optical amplifiers with semiconductor materials;

[0037] [Fig.7] The [Fig.7] is a schematic representation of a photonic chip according to a second variant of a second embodiment of the present invention, the photonic chip according to this second embodiment includes in particular two Mach Zehnder modulators and four optical amplifiers with semiconductor materials;

[0038] [Fig.8] The [Fig.8] represents the photonic chip of the [Fig.7] associated with an intermediate module;

[0039] [Fig.9] Fig.9 is a schematic representation of a photonic chip according to a third embodiment of the present invention, the photonic chip according to this third embodiment includes in particular two Mach Zehnder modulators and two optical amplifiers with semiconductor materials. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention relates to a photonic chip, and more particularly to a photonic chip provided with one or two Mach Zehnder modulators formed on and / or in a layer, called a waveguide layer, resting on a front face of a support substrate.

[0041] According to the present invention, the Mach Zehnder modulator(s) are arranged between an optical input and an optical output, such that light radiation injected at the optical input is divided into a first radiation and a second radiation intended to be guided by the Zehnder Mach modulator(s), and then recombined at the optical output.

[0042] The optical chip includes at least two optical amplifiers made of semiconductor materials arranged to separately amplify the first and second radiation before their recombination at the optical output.

[0043] Fig. 2 is a schematic representation of a Zehnder 100 Mach modulator that can be implemented within the framework of the present invention.

[0044] In particular, the Zehnder Mach modulator 100 can be formed on or in a layer, called waveguide layer 200, resting on a front face 310 of a support substrate 300 ([Fig.3]).

[0045] The support substrate 300 may comprise any type of material, and more particularly a semiconductor material. In particular, the semiconductor material may comprise silicon, or an IILV semiconductor. Alternatively, the support substrate 300 may comprise a piezoelectric material, and in particular lithium niobate (LiNbO3).

[0046] The waveguide layer 200 may comprise a dielectric material, for example silicon dioxide.

[0047] According to the terms of the present invention, a Mach Zehnder modulator comprises two modulation branches called, respectively, first branch 101 and second branch 102.

[0048] The first branch 101 and the second branch 102 are connected, at one of their ends, by an intermediate optical input 103, and, at the other of their ends, by an intermediate optical output 104.

[0049] More specifically, the first branch 101 and the second branch 102 each comprise a waveguide referred to, respectively, as first waveguide 101a and second waveguide 102a. The first branch 101 and the second branch 102 each comprise a modulation section referred to, respectively, as first modulation section 105 and second modulation section 106.

[0050] The modulation section of a given modulation branch is configured to modulate the phase of a light radiation that can be guided by the modulation branch considered.

[0051] A modulation section of a modulation branch may in particular include a section of the waveguide of said branch, called modulation waveguide, and an electrode intended to impose an electrical potential on said modulation waveguide.

[0052] A modulation section is configured in particular so that an electrical potential imposed by the electrode on the modulation waveguide modifies the refractive index of the modulation waveguide in question. This modification of the index makes it possible to impose a phase shift to a light beam that can be guided by the modulation section considered. In this respect, the modulation waveguide may comprise a doped silicon waveguide, and more particularly a silicon waveguide accommodating a PN junction. Such a waveguide has a refractive index that can be modulated according to an applied electrical potential. Document [3] cited at the end of the description provides an example that a person skilled in the art can implement within the scope of the present invention. The invention is not, however, limited to these aspects alone, and a person skilled in the art can consider other solutions. In particular, and by way of example, the first modulation waveguide 108 and the second modulation waveguide 110 may comprise an IILV semiconductor or even LiNbO3, for example, transferred by bonding to the substrate.

[0053] Thus, the modulation waveguide and the electrode of the first modulation section 105, respectively called first modulation guide 108 and first electrode 109, make it possible to impose a phase modulation, called first phase shift, on a light radiation guided by the first branch 101. This first phase shift is in particular modulated by the electrical potential, called first potential, imposed by the first electrode 109.

[0054] Equivalently, the modulation waveguide and the electrode of the second modulation section 106, respectively called the second modulation guide 110 and the second electrode 111, make it possible to impose a phase modulation, called the second phase shift, on a light radiation guided by the second branch 102. This second phase shift is in particular modulated by the electrical potential, called the second potential, imposed by the second electrode 111.

[0055] According to the present invention, the first potential and the second potential can be equal to, respectively, u(t) / 2 and -u(t) / 2. Under these conditions, the phase shift imposed by the first modulation section 105 and by the second modulation section 106 are equal to, respectively, Mu(t) / 2 and -Mu(t) / 2 (M is an efficiency factor of a modulator).

[0056] The second branch 102 may also include a phase-shift module 107 configured to impose a fixed phase shift <e>to a light radiation capable of being guided by said second branch 102 adding to the phase shift -Mu(t) / 2.

[0057] Thus, a light beam of intensity Pin, injected at the intermediate optical input 103, is split into two beams to be guided, respectively, by the first branch 101 and the second branch 102. The beam guided by the first branch 101 undergoes a phase shift equal to Mu(t) / 2, while the beam guided by the second branch 102 undergoes a phase shift equal to -Mu(t) / 2 + ¢. These two beams, guided respectively by the first branch 101 and the second branch 102 are then recombined at the intermediate optical output 104 to form an output radiation of intensity Pout.

[0058] For a fixed phase shift <e>equal to ji / 2, Pout follows the following law: Pout = Pin / 2 + Pin / 2 * sin(Mu(t))

[0059] It is understood, without the need for further specification, that a modulation branch of a Mach-Zehnder modulator according to the terms of the present invention forms an optical path without branching. In other words, light injected at the intermediate optical input of a Mach-Zehnder modulator undergoes only a single division.

[0060] The Mach Zehnder 100 modulator described above is integrated into a photonic chip 10 of the present invention. More particularly, the photonic chip 10 according to the present invention comprises one or two Mach Zehnder 100 modulators whose modulation branches are arranged between an optical input 112 and an optical output 113 such that light injected at the optical input is split into a first beam and a second beam intended to be guided by the Mach Zehnder 100 modulator(s), and are then recombined at the optical output.

[0061] The optical chip 10 includes at least two optical amplifiers made of semiconductor materials arranged to separately amplify the first and second radiation before their recombination at the optical output.

[0062] Figure 4 is a schematic representation of a photonic chip 10 according to a first variant of a first embodiment of the present invention and implementing a Zehnder 100 Mach modulator as described above.

[0063] In particular, the photonic chip 10, according to this first embodiment, comprises a single Zehnder Mach modulator 100 and for which the fixed phase shift ​

[0064] The photonic chip 10 further comprises two optical amplifiers of semiconductor materials called, respectively, first amplifier 114 and second amplifier 115 substantially identical.

[0065] The first amplifier 114 is arranged on the first branch 101, while the second amplifier 115 is arranged on the second branch 102. The first amplifier 114 and the second amplifier 115 are thus arranged to amplify, according to a gain G, respectively, the first radiation and the second radiation.

[0066] The integration of a semiconductor optical amplifier with a waveguide is described in document [1] cited at the end of the description. In particular, such a semiconductor optical amplifier may include a multi-quantum well formed of InGaAsP layers. More specifically, this semiconductor optical amplifier may form a hybrid waveguide coupled with the waveguide of the modulation branch. This coupling may involve a transition section, and in particular a tapered waveguide. More specifically, the coupling may be adiabatic as described in document [4] cited at the end of the description.

[0067] Furthermore, an optical amplifier made of semiconductor materials can be bonded or formed by epitaxy on a waveguide, and in particular a silicon waveguide.

[0068] According to the first embodiment, the semiconductor optical amplifier of a modulation branch is arranged downstream of the modulation section of the modulation branch in question. In other words, the first amplifier 114 is arranged between the first modulation section 105 and the intermediate optical output 103, while the second amplifier 115 is arranged between the second modulation section 106 and the intermediate optical output 104.

[0069] Figure 5 illustrates a second variant of the first embodiment of the present invention. According to this second variant, the semiconductor optical amplifier of a modulation branch is arranged upstream of the modulation section of the modulation branch in question. In other words, the first amplifier 114 is arranged between the intermediate optical input 103 and the first modulation section 105, while the second amplifier is arranged between the intermediate optical input 103 and the second modulation section 106.

[0070] The arrangement of optical amplifiers made of semiconductor materials according to this first embodiment makes it possible to amplify phase-modulated light radiation only, and not intensity-modulated light as described in document [1] cited at the end of the description. In other words, this arrangement makes it possible to limit, or even prevent, the non-linearity effects of optical amplifiers made of semiconductor materials.

[0071] The present invention also relates to a second embodiment. In this regard, [Fig. 6] illustrates a first variant of the second embodiment.

[0072] The photonic chip according to this second embodiment comprises two identical Mach Zehnder 100 modulators, respectively called modulator I 100a and modulator Q 100b, so that the photonic chip 10 forms an IQ modulator.

[0073] The modulator I 100a and the modulation Q 100b essentially reproduce the architecture of the Zehnder Mach 100 modulator of the first variant of the first embodiment.

[0074] In particular, the first branch 101a and the second branch 102a of the modulator I 100a are connected, at one of their ends, by the intermediate optical input called input I 103a, and at the other of their ends, by the intermediate optical output, called output I 104a. Equivalently, the first branch 101b and the second branch 102b of the modulator Q 100b are connected, at one of their ends, by the intermediate optical input called input Q 103b, and at the other of their ends, by the intermediate optical output, called output Q 104b.

[0075] The first branch 101a and the second branch 102a of the modulator I also include, respectively, the first modulation section 105a and the second modulation section 106a.

[0076] Equivalently, the first branch 101b and the second branch 102b of the modulator Q also include, respectively, the first modulation section 105b and the second modulation section 106b.

[0077] The second branch 102a and the second branch 102b each comprise a phase-shift module, referred to, respectively, as module I 107a and module Q 107b. In particular, module I 107a and module Q 107b are configured to impose a phase shift <e>equal to jt.

[0078] The photonic chip 10 further comprises four optical amplifiers made of semiconductor materials, referred to as first amplifier I 114a, second amplifier I 115a, first amplifier Q 114b, and second amplifier Q 115b. In particular, first amplifier I 114a and second amplifier I 115a are arranged respectively on the first branch 101a and second branch 102a of modulator I 100a. Equivalently, first amplifier Q 114b and second amplifier Q 115b are arranged respectively on the first branch 101b and second branch 102b of modulator Q 100b.

[0079] More particularly, according to the first variant of the second embodiment, the optical amplifier of semiconductor materials of a modulation branch of a Mach Zehnder modulator is disposed between the modulation section of the modulation branch considered and the intermediate optical output of said Mach Zehnder modulator.

[0080] Thus, the first amplifier I 114a is arranged between the first modulation section 105a and the output I 104a.

[0081] The second amplifier I 115a is arranged between the second modulation section 106a and the output I 104a.

[0082] The first amplifier Q 114b is arranged between the first modulation section 105b and the output Q 104b.

[0083] The second amplifier Q 115b is arranged between the second modulation section 106b and the output Q 104b.

[0084] The photonic chip 10 includes a radiation splitter 116 and a radiation combiner 117.

[0085] In particular, the radiation splitter 116 comprises two waveguides called, respectively, input guide I 116a and input guide Q 116b. Input guide I 116a connects the optical input 112 with the input I 103a of the modulator I 110a. Equivalently, input guide Q 116b connects the optical input 112 with the input Q 103b of the modulator I 110b.

[0086] The radiation combiner 117 comprises two waveguides called, respectively, output guide I 117a and output guide Q 117b. Output guide I 117a connects the optical output 113 with the output I 104a. Output guide Q 117b connects the optical output 113 with the output Q 104b of the modulator Q 100b.

[0087] The photonic chip may include another phase-shift module 118 configured to impose another phase shift <d’ fixe égal à ir 2 un rayonnement lumineux entre la sortie q 104b et optique 113.

[0088] Thus, a light beam injected at the optical input 112, for example by the laser 400, is divided into two beams called first beam and second beam injected at the level of, respectively, the input I and the input Q. The first beam is modulated by the modulator I, to form a first modulated beam, while the second beam is modulated by the modulator Q to form a second modulated beam.

[0089] The radiation combiner 117 then combines the first modulated radiation and the second modulated radiation into an output radiation.

[0090] The arrangement of the optical amplifiers made of semiconductor materials according to this first variant of the second embodiment makes it possible to amplify phase-modulated light radiation only, and not intensity-modulated light as described in document [1] cited at the end of the description. In other words, this arrangement makes it possible to limit, or even prevent, the non-linearity effects of the optical amplifiers made of semiconductor materials.

[0091] The second embodiment also includes a second variant illustrated in [Fig. 7] which differs from the first variant in that the optical amplifier made of semiconductor materials of a modulation branch of a modulator Mach Zehnder is disposed between the modulation section of the modulation branch under consideration and the intermediate optical input of said Mach Zehnder modulator.

[0092] Thus, the first amplifier I 114a is arranged between the input I 103a and the first modulation section 105a.

[0093] The second amplifier I 115a is arranged between the input I 103a and the second modulation section 106a.

[0094] The first amplifier Q 114b is arranged between the input Q 103b and the first modulation section 105b.

[0095] The second amplifier Q 115b is arranged between the input Q 103b and the second modulation section 106b.

[0096] The arrangement relating to this second variant is particularly advantageous since the light radiation likely to be injected at the optical input 112 has a reduced intensity.

[0097] In particular, an intermediate module 500 ([Fig.8]) can be interposed between the source 400 and the optical input 112. In particular, the intermediate module 500 includes a first radiation divider 501, a second radiation divider 502, a local oscillator 503, and a TM modulator 504.

[0098] The first radiation splitter 501 is configured to split a light beam, emitted by the laser, into two intermediate beams. One of these two beams is injected into the local oscillator 503, while the second oscillator receives the other of these two intermediate beams. The latter is in turn split by the second radiation splitter 502 into two intermediate second beams. One of these two intermediate second beams is injected into the TM modulator 504, while the optical input 112 receives the other of these two intermediate second beams.

[0099] According to this configuration, the losses in the radiation dividers are significant. The implementation of the four optical amplifiers made of semiconductor materials is therefore particularly advantageous.

[0100] The arrangement of the optical amplifiers made of semiconductor materials according to this second variant of the second embodiment makes it possible to amplify phase-modulated light radiation only, and not intensity-modulated light as described in document [1] cited at the end of the description. In other words, this arrangement makes it possible to limit, or even prevent, the non-linearity effects of the optical amplifiers made of semiconductor materials.

[0101] Figure [Fig.9] represents the photonic chip 10 according to a third embodiment of the present invention.

[0102] This third embodiment differs from the first variant of the second embodiment in that said chip comprises only two amplifiers optical elements with semiconductor materials called, respectively, amplifier I 114c and amplifier Q 115c, and carried, respectively, by the output guide I 117a and the output guide Q 117b.

[0103] This third embodiment is advantageous when the modulator I and the modulator Q are used solely as phase modulators to produce a constellation known as 'phase shift keying'. According to this configuration, the light radiation at the output I 104a and the output Q 104b is not intensity modulated. Each of the two optical amplifiers made of semiconductor materials, referred to respectively as amplifier I 114c and amplifier Q 115c, and carried respectively by the output guide I 117a and the output guide Q 117b, amplifies only phase-modulated radiation.

[0104] 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. references

[0105] [1] T. Hiraki et al., “InGaAsP Membrane Mach-Zehnder Modulator Integrated With Optical Amplifier on Si Platform" J. Lightwave Technol. 38, 3030-3036 (2020);

[0106] [2] R. Bonk et al., “Linear semiconductor optical amplifiers for amplification of advanced modulation formats" Opt. Express 20, 9657-9672 (2012);

[0107] [3] Reed, G et al., "Silicon optical modulation ors'" Nature Photon 4, 518-526 (2010);

[0108] [4] S. Menezo et al., “Back-Side-On-BOX heterogeneous laser integration for fully integrated photonic circuits on Silicon" 45th European Conference on Optical Communication (ECOC 2019), 2019, pp. 1-3. < / e> < / e> < / e>

Claims

1. Demands Photonic chip (10) comprising: - a support substrate (300) provided with a front face (310); - a waveguide layer (200) resting on the front face; - two Mach-Zehnder modulators (100a, 100b), respectively called I-modulator (100a) and Q-modulator (100b), such that the photonic chip forms an IQ modulator. The two Mach-Zehnder modulators, being formed on and / or within the waveguide layer, each comprise two modulation branches, called the first branch (101a, 101b) and the second branch (102a, 102b), arranged between the optical input (112) and an optical output (113). Light injected at the optical input (112) is split into a first and a second beam, which are modulated by the I-modulator (110a) and the Q-modulator (100b), respectively, and then recombined at the optical output (113). Each of the two modulation branches of a Mach-Zehnder modulator comprises a modulation section. (105a, 105b, 106a, 106b) formed by a waveguide, called a modulation waveguide, and a modulation element,the modulation element being configured to modulate the phase of radiation that can be guided by the modulation waveguide, the second branch (102a, 102b) also comprising a phase-shifting module (107a, 107b) configured to impose a fixed phase shift on light radiation that can be guided by said second branch (102a, 102b), the first branch (101a) and the second branch (102a) of the modulator I (100a) being connected, at one of their ends, by an intermediate optical input called input I (103a), and, at the other end, by an intermediate optical output called output I (104a), the first branch (101b) and the second branch (102b) of the modulator Q (100b) being connected, at one end, by another intermediate optical input called input Q (103b), and, at the other end, by an intermediate optical output called output Q (104a). at the ends, via another intermediate optical output called output Q (104b); The photonic chip also includes a radiation splitter (116) and a radiation combiner (117), the radiation splitter comprising two waveguides called, respectively, input guide I (116a) and input guide Q (116b), the guide

2.

3.

4. input I and input guide Q connecting the optical input (112) with, respectively, input I and input Q, so that the first radiation and the second radiation are injected at, respectively, input I and input Q, the radiation combiner comprising two waveguides called, respectively, output guide I and output guide Q, output guide I (117a) and output guide Q (117b) connecting an optical output (113) with, respectively, output I and output Q; the photonic chip includes two optical amplifiers made of semiconductor materials (114c, 115c) called, respectively, amplifier I and amplifier Q carried, respectively, by the output guide I and the output guide Q. Photonic chip according to claim 1, wherein said photonic chip further comprises another phase-shifting module configured to impose another fixed phase shift on a light beam between the Q output and the optical output (113). Photonic chip according to claim 1 or 2, wherein the modulation waveguide comprises silicon, advantageously doped silicon, even more advantageously a PN junction along the silicon waveguide. Photonic chip according to claim 3, wherein the at least two optical amplifiers of semiconductor materials comprise a waveguide made of III-V semiconductor materials.

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