Glass and silicon photonics hybrid integrated structure and manufacturing method therefor

Abstract

A glass and silicon photonics hybrid integrated structure and a manufacturing method therefor. The structure comprises a glass conversion waveguide (1) and a silicon photonics chip (2); one side of the glass conversion waveguide (1) is provided with an input port (11), and the other side of the glass conversion waveguide (1) is provided with a first light-splitting port (12) and a second light-splitting port (13); and one side of the silicon photonics chip (2) is provided with a first optical input port (21) and a second optical input port (22), the first light-splitting port (12) being coupled to the first optical input port (21), and the second light-splitting port (13) being coupled to the second optical input port (22), such that the glass conversion waveguide (1) is coupled to the silicon photonics chip (2). Coupling the glass conversion waveguide (1) to the silicon photonics chip (2), and using the glass conversion waveguide (1) as a light entrance waveguide of the whole optical path can effectively avoid the two-photon effect and reduce the mode field mismatch during coupling of silicon waveguides and external optical paths, thus improving the overall performance of silicon photonics products.

Description

A hybrid integrated structure of glass and silicon light and its manufacturing method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from the following patent applications:

[0003] (1) A Chinese patent application entitled “A hybrid integrated structure of glass and silicon light and its manufacturing method”, filed with the China Patent Office on January 2, 2024, with application number 202410002798.7; Technical Field

[0004] The present invention relates to the field of communication technology, and in particular to a hybrid integrated structure of glass and silicon light and a manufacturing method thereof. Background Art

[0005] In recent years, silicon photonics technology has developed rapidly. Due to its advantages such as high speed, low energy consumption, low cost and high integration, silicon photonics technology has been widely used in various fields such as the Internet, big data, cloud computing and smart terminals.

[0006] However, with the further improvement of optical communication speed and packaging density, especially in the application of future co-packaged optics (CPO) optical engines, the original defects of silicon photonics are gradually exposed.

[0007] On the one hand, the transmission loss of silicon waveguides is higher than that of traditional optical waveguides. When silicon waveguides are directly coupled with FA or optical fiber, there is often significant coupling loss due to mode field mismatch. Under the same input optical power, the output optical power of silicon waveguides is relatively low and cannot meet the system optical power requirements.

[0008] For optical engines, the use of higher-output-power lasers can reduce the number of lasers and lower system packaging costs. Existing CPO optical engines typically achieve output powers exceeding 20dBm. On the other hand, research has shown that when the input power exceeds 15dBm, the nonlinear effects of silicon waveguides become very pronounced. Two-photon absorption in silicon waveguides increases optical path loss and, in severe cases, can cause irreversible damage, thus limiting their application.

[0009] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in this technical field.

[0010] Application Contents

[0011] The technical problem to be solved by the present invention is how to overcome the mode field mismatch caused by the existing coupling between silicon waveguide and optical fiber, and the problem that the nonlinear effect and two-photon absorption effect of the silicon waveguide will increase the loss of the optical path when the optical power exceeds 15dBm.

[0012] The embodiment of the present invention adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a hybrid integrated structure of glass and silicon photonics, comprising a glass conversion waveguide 1 and a silicon photonics chip 2;

[0014] An input port 11 is provided on one side of the glass conversion waveguide 1, and at least a first splitting optical port 12 and a second splitting optical port 13 are provided on the other side of the glass conversion waveguide 1;

[0015] At least a first input optical port 21 and a second input optical port 22 are provided on one side of the silicon photonic chip 2. The first splitting optical port 12 is coupled to the first input optical port 21, and the second splitting optical port 13 is coupled to the second input optical port 22, so that the glass conversion waveguide 1 is coupled to the silicon photonic chip 2.

[0016] Preferably, an optical splitter 14 is provided in the glass conversion waveguide 1 and is arranged after the input port 11 so as to divide the optical port in the glass conversion waveguide 1 into a first splitting optical port 12 and a second splitting optical port 13 through the optical splitter 14 .

[0017] Preferably, a first positioning mark 15 is provided in the glass conversion waveguide 1, and a second positioning mark 23 is provided on the silicon photonic chip 2. When the glass conversion waveguide 1 is coupled with the silicon photonic chip 2, the first positioning mark 15 is aligned with the second positioning mark 23 to facilitate alignment and coupling of the glass conversion waveguide 1 with the silicon photonic chip 2.

[0018] Preferably, the glass conversion waveguide 1 and the silicon photonic chip 2 are coupled by bonding using a coupling matching adhesive.

[0019] Preferably, the input optical power at the input port 11 of the glass conversion waveguide 1 is greater than or equal to 15 dBm.

[0020] Preferably, the glass conversion waveguide 1 is provided with an output light port 16 and a signal light port 17;

[0021] The silicon photonic chip 2 further includes a transmitter 24 and a receiver 25. A modulator 241 is provided in the transmitter 24. One end of the transmitter 24 is connected to the first input optical port 21, and the other end of the transmitter 24 is connected to the output optical port 16. The optical signal is transmitted from the first input optical port 21 to the modulator 241 of the transmitter 24, so that the optical signal is modulated and then transmitted from the output optical port 16.

[0022] One end of the receiver 25 is connected to one end of the second input optical port 22, and the other end of the second input optical port 22 is connected to the signal optical port 17. A mixer 251 is provided in the receiver 25. The optical signal is transmitted from the second input optical port 22 to the mixer 251 of the receiver 25 to facilitate the conversion of the optical and electrical signals.

[0023] Preferably, the glass conversion waveguide 1 and the silicon photonic chip 2 are end-face coupled, specifically:

[0024] The front face of the glass conversion waveguide 1 is in the same direction as the front face of the silicon photonic chip 2, and the optical port in the glass conversion waveguide 1 and the optical port of the silicon photonic chip 2 are on the same horizontal plane, so that the first positioning mark 15 and the second positioning mark 23 are aligned, so as to facilitate coupling and alignment of the glass conversion waveguide 1 and the silicon photonic chip 2.

[0025] Preferably, the glass conversion waveguide 1 and the silicon photonic chip 2 adopt planar evanescent wave coupling, specifically:

[0026] The front face of the glass conversion waveguide 1 faces downward, and the front face of the silicon photonic chip 2 faces upward, so that the first positioning mark 15 is aligned with the second positioning mark 23, so as to facilitate coupling and alignment of the glass conversion waveguide 1 and the silicon photonic chip 2.

[0027] Preferably, the glass conversion waveguide 1 and the silicon photonic chip 2 are coupled by etching, specifically:

[0028] A groove matching the glass conversion waveguide 1 is etched on the silicon photonic chip 2, and the glass conversion waveguide 1 is arranged in the groove so that the optical port of the glass conversion waveguide 1 and the optical port of the silicon photonic chip 2 are kept in the same plane and aligned and coupled.

[0029] In a second aspect, the present invention further provides a method for manufacturing a hybrid integrated structure of glass and silicon photonics, wherein the method is applicable to the hybrid integrated structure of glass and silicon photonics described in the first aspect, comprising:

[0030] Align the first splitting optical port 12 of the glass conversion waveguide 1 with the first input optical port 21 of the silicon photonic chip 2, and align the second splitting optical port 13 of the glass conversion waveguide 1 with the second input optical port 22 of the silicon photonic chip 2;

[0031] The glass conversion waveguide 1 is bonded and coupled to the silicon photonic chip 2 by using matching glue.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention couples a glass conversion waveguide 1 with a silicon photonic chip 2 and uses the glass conversion waveguide 1 as the optical waveguide of the entire optical path. The glass conversion waveguide 1 is made of glass. Through the splitting effect of the glass conversion waveguide 1, the high-power optical signal input from the input port 11 of the glass conversion waveguide 1 is split and emitted from the first splitting optical port 12 and the second splitting optical port 13 respectively. Since the glass conversion waveguide 1 is made of glass, the two-photon effect can be effectively avoided, and the mode field mismatch between the silicon waveguide and the external optical path can be reduced, thereby improving the overall performance of the silicon photonic product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] FIG1 is a schematic diagram of a glass conversion waveguide structure of a hybrid integrated structure of glass and silicon optical provided by an embodiment of the present invention;

[0036] FIG2 is a schematic diagram of a silicon photonic chip structure having a hybrid integrated structure of glass and silicon photonics provided by an embodiment of the present invention;

[0037] FIG3 is a schematic diagram of the structure of the coupling between the glass conversion waveguide and the silicon photonic chip provided by an embodiment of the present invention;

[0038] FIG4 is a schematic diagram of the structure of a modulator and a mixer in a silicon photonic chip provided by an embodiment of the present invention;

[0039] FIG5 is a side view of an end-face coupling of a glass conversion waveguide and a silicon photonic chip provided by an embodiment of the present invention;

[0040] FIG6 is a side view of a glass-converted waveguide and a silicon photonic chip using planar evanescent wave coupling according to an embodiment of the present invention;

[0041] FIG7 is a side view of a glass conversion waveguide and a silicon photonic chip coupled by etching according to an embodiment of the present invention;

[0042] FIG8 is a schematic diagram of a cross-sectional structure of a glass conversion waveguide coupled with a silicon photonic chip in a preferred coupling manner according to an embodiment of the present invention;

[0043] FIG9 is a schematic structural diagram of a preferred coupling method between a glass conversion waveguide and a silicon photonic chip provided in an embodiment of the present invention;

[0044] FIG10 is a flow chart of a method for manufacturing a hybrid integrated structure of glass and silicon light provided by an embodiment of the present invention;

[0045] Wherein, the accompanying drawings are marked as follows:

[0046] 1-glass conversion waveguide; 11-input port; 12-first splitter optical port; 13-second splitter optical port; 14-optical splitter; 15-first positioning mark; 16-output optical port; 17-signal optical port; 18-waveguide; 19-bump; 2-silicon photonic chip; 21-first input optical port; 22-second input optical port; 23-second positioning mark; 24-emitter; 241-modulator; 25-receiver; 251-mixer; 26-first receiving slot; 27-second receiving slot. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0048] In the description of the present invention, the terms "inside", "outside", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0049] The terms "first," "second," etc., used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of such features. In the description of this disclosure, unless otherwise specified, "plurality" means two or more.

[0050] In the present invention, unless otherwise specified or limited, the term "connection" should be understood broadly. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediary. In addition, the term "coupling" can refer to the manner in which electrical connection is achieved for signal transmission.

[0051] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0052] Embodiment 1:

[0053] Embodiment 1 of the present invention provides a hybrid integrated structure of glass and silicon photonics, as shown in FIG1 to FIG3 , including a glass conversion waveguide 1 and a silicon photonics chip 2;

[0054] An input port 11 is provided on one side of the glass conversion waveguide 1, and at least a first splitting optical port 12 and a second splitting optical port 13 are provided on the other side of the glass conversion waveguide 1;

[0055] At least a first input optical port 21 and a second input optical port 22 are provided on one side of the silicon photonic chip 2. The first splitting optical port 12 is coupled to the first input optical port 21, and the second splitting optical port 13 is coupled to the second input optical port 22, so that the glass conversion waveguide 1 is coupled to the silicon photonic chip 2.

[0056] The hybrid integrated structure of glass and silicon photonics in the embodiment of the present invention includes a glass conversion waveguide 1 and a silicon photonics chip 2. The glass conversion waveguide 1 is made of glass, which has excellent light transmittance compared to existing silicon photonics chips 2. Laser focusing, with its high energy density at the focal point, produces a two-photon polymerization reaction, which changes the refractive index at the focal point of the glass, forming the glass conversion waveguide 1 of the embodiment of the present invention. When forming a waveguide within the glass, cold processing using a femtosecond laser easily creates a printed waveguide within the glass.

[0057] Glass also boasts low cost, excellent transparency, a high optical damage threshold, and a refractive index very close to that of optical fiber, resulting in very low coupling losses. The present embodiment utilizes a glass conversion waveguide 1 as the input waveguide for the entire optical path. This not only avoids the two-photon effect but also serves as mode field conversion for silicon waveguides, thereby reducing coupling losses. Furthermore, in practical applications, the glass conversion waveguide 1 can also be used to fabricate circuits and through-glass vias. Its excellent high-frequency performance makes it well-suited for high-speed signal transmission.

[0058] Due to the reversibility of the optical path, when light according to an embodiment of the present invention is input from the input port 11 on the glass conversion waveguide 1 side and input to the silicon photonic chip 2 side, the glass conversion waveguide 1 primarily functions to convert optical power, that is, to split high-power external input light into multiple optical outputs. When light according to an embodiment of the present invention is input from the silicon photonic chip 2 side to the glass conversion waveguide 1 side, the glass conversion waveguide 1 primarily functions to synthesize multiple, low-probability inputs from the silicon photonic chip 2 into high-power optical output. It is worth noting that the glass conversion waveguide 1 according to an embodiment of the present invention is provided with at least two splitter ports (a first splitter port 12 and a second splitter port 13) on the other side of the glass conversion waveguide. These ports need to match the number of input ports within the silicon photonic chip 2 on the opposite side. For example, assuming four input ports are provided on the silicon photonic chip 2 side, four splitter ports are required on the corresponding glass conversion waveguide 1. In addition, the silicon photonic chip 2 of the embodiment of the present invention can be replaced according to actual conditions. When input light ports are provided on both sides of the silicon photonic chip 2 of the embodiment of the present invention, a glass conversion waveguide 1 can be hybrid-integrated at both ends of the silicon photonic chip 2 to form a more complex hybrid integrated structure of glass and silicon photonics. The principle mechanism is the same as mentioned above and will not be elaborated here.

[0059] The hybrid integrated structure of glass and silicon photonics in the embodiment of the present invention separates a portion of the passive structure from the existing silicon waveguide into the optical circuit. A glass conversion waveguide 1 is constructed from glass and then hybrid-integrated with a silicon photonics chip 2. This effectively mitigates the waveguide's two-photon effect and reduces the mode field mismatch between the silicon waveguide and the external optical path, thereby improving the overall performance of the silicon photonics product. The glass conversion waveguide 1 in the embodiment of the present invention is a mode field conversion waveguide. The refractive index of glass is between 1.470 and 1.700, close to that of optical fiber, while the refractive index of the silicon waveguide (silicon photonics chip 2) is 3.42. Directly coupling optical fiber to the silicon waveguide will result in a significant mode field mismatch. However, femtosecond laser cold processing technology can be used to change the refractive index of the glass conversion waveguide 1. Adjusting the laser focus energy adjusts the refractive index of the glass conversion waveguide 1, and adjusting the size and structure of the glass conversion waveguide 1 adjusts the mode field at both ends of the glass conversion waveguide 1. The glass conversion waveguide 1 reduces the mode field size at one end so that it can be connected to the silicon waveguide (silicon photonic chip 2), and increases the mode field at the other end so that it can be connected to an optical fiber, a lens or other planar waveguide, thereby realizing the conversion of the mode field. In addition, the glass conversion waveguide 1 is also a space conversion waveguide, and most common waveguides are planar waveguides. Due to the small size of the silicon waveguide (silicon photonic chip 2), they are often densely arranged. However, the outer diameter of the optical fiber or lens is large and the spacing is very wide. In particular, when the silicon waveguide (silicon photonic chip 2) is coupled with the lens, a space transformation process is required. The split-second laser printing of the glass conversion waveguide 1 can not only form a one-dimensional waveguide, but also process a two-dimensional waveguide and a three-dimensional waveguide. Through laser 3D printing technology, a fan-in and fan-out waveguide can be formed in the glass, which can effectively solve the problem of spatial matching of the coupling between the silicon waveguide and different external media. In order to illustrate the complete scheme of the embodiment of the present invention, the details of the embodiment of the present invention are explained in detail below. The glass conversion waveguide 1 described in this embodiment of the present invention is also a mode field conversion waveguide. The input optical signal is transmitted through the glass conversion waveguide 1 to the silicon photonic chip 2. The glass conversion waveguide 1 can convert the horizontal light output from the silicon waveguide into vertical light output, or convert the vertical light output from the silicon waveguide into horizontal light output. To smoothly transmit the input optical signal to the silicon photonic chip 2, the glass conversion waveguide 1 described in this embodiment of the present invention is provided with an optical splitter 14. The optical splitter 14 is disposed after the input port 11, so that the optical splitter 14 can separate the input port 11 of the glass conversion waveguide 1 into a first splitting optical port 12 and a second splitting optical port 13.

[0060] In this embodiment of the present invention, an optical splitter 14 is provided within the glass-converted waveguide 1. The input port 11 is split into a first optical splitting port 12 and a second optical splitting port 13 by the optical splitter 14. When the optical signal input from the input port 11 exceeds 15 dBm, the glass-converted waveguide 1, made of glass, effectively avoids the two-photon effect. Furthermore, to ensure that the optical power entering the silicon waveguide does not exceed 15 dBm, the glass-converted waveguide replaces part of the optical splitting structure within the silicon waveguide. The optical signal input from the optical port 11 is split into two by the optical splitting structure within the glass-converted waveguide. The two equally divided light paths enter the corresponding first optical splitting port 12 and second optical splitting port 13, respectively. The optical power of each path is significantly less than 15 dBm. For example, when the optical signal input from the input port 11 is 18 dBm, after the optical splitter 14 is applied, the optical signals transmitted from the first optical splitting port 12 and the second optical splitting port 13 are both less than 15 dBm. It is worth noting that the output optical power of the intrinsic tunable laser is generally around 15dBm, and better manufacturers can achieve 17 to 18dBm. In order to avoid the two-photon effect, the glass conversion waveguide described in the embodiment of the present invention has at least one-level splitting structure. When the input optical power is greater than 18dBm, a two-level splitting structure may be required. For example, the input optical power of the input port 11 can be set to 18dBm, but is not limited to it. Under the action of the same input optical power, the optical power density of the silicon photonic chip 2 after passing through the glass conversion waveguide 1 is reduced by half in the embodiment of the present invention. Even if the external laser optical power reaches 18dBm, the maximum optical power entering the silicon waveguide after conversion through the glass conversion waveguide 1 is only 15dBm, which can effectively reduce the two-photon effect of the device. At the same time, the glass conversion waveguide 1 is used to expand the mode field diameter of the silicon waveguide, so that it can better couple with the external optical fiber or FA, thereby improving the coupling efficiency. The total loss of the coupling of the silicon photonic chip 2 is reduced as a whole.

[0061] In practical applications, if the optical signal input from input port 11 is relatively large, a multi-stage splitting glass conversion waveguide 1 can be used to reduce the optical signal reaching silicon photonic chip 2 to less than 15dBm. For example, when the input optical power is 21dBm, a two-stage splitting glass conversion waveguide can be used. The first stage of splitting is followed by the second stage. For a 50% splitting ratio glass conversion waveguide, the optical power drops by 3dB at each stage. After two stages of splitting, the optical power input to the silicon waveguide is guaranteed to be less than 15dBm.

[0062] Continuing with FIG1 , to smoothly couple the glass-converted waveguide 1 with the silicon photonic chip 2, a first alignment mark 15 is provided within the glass-converted waveguide 1, and a second alignment mark 23 is provided on the silicon photonic chip 2. When coupling the glass-converted waveguide 1 with the silicon photonic chip 2, the first alignment mark 15 is aligned with the second alignment mark 23, thereby facilitating alignment and coupling of the glass-converted waveguide 1 with the silicon photonic chip 2. It is worth noting that the alignment and coupling of the glass-converted waveguide 1 with the silicon photonic chip 2 in this embodiment of the present invention actually involves aligning and coupling the first splitter optical port 12 within the glass-converted waveguide 1 with the corresponding input optical port on the silicon photonic chip 2, and aligning and coupling the second splitter optical port 13 within the glass-converted waveguide 1 with the corresponding optical port on the silicon photonic chip 2. By providing the first alignment mark 15 within the glass-converted waveguide 1 and the second alignment mark 23 within the silicon photonic chip 2, when the glass-converted waveguide 1 and the silicon photonic chip 2 are aligned and coupled, the first alignment mark 15 and the second alignment mark 23 are precisely aligned and coupled. During the actual coupling process, the first positioning mark 15 is aligned with the second positioning mark 23 so as to achieve coupling alignment between the glass conversion waveguide 1 and the silicon photonic chip 2 .

[0063] After the first alignment mark 15 and the second alignment mark 23 are aligned, bonding is performed using matching adhesive to ensure that the glass conversion waveguide 1 and the silicon photonic chip 2 are coupled and bonded together. Specifically, the glass conversion waveguide 1 and the silicon photonic chip 2 are bonded using a matching adhesive. It is worth noting that the matching adhesive in this embodiment of the present invention can be, but is not limited to, UV adhesive, with a refractive index between that of silicon waveguides and glass waveguides.

[0064] Next, the internal structures of the glass conversion waveguide 1 and the silicon photonic chip 2 according to an embodiment of the present invention are described in detail. Specifically, as shown in Figures 1 and 4, the glass conversion waveguide 1 according to the embodiment of the present invention is provided with an output optical port 16 and a signal optical port 17; the silicon photonic chip 2 also includes a transmitter 24 and a receiver 25. A modulator 241 is provided in the transmitter 24, one end of the transmitter 24 is connected to the first input optical port 21, and the other end of the transmitter 24 is connected to the output optical port 16. The optical signal is transmitted from the first input optical port 21 to the modulator 241 of the transmitter 24, so that the optical signal is modulated and transmitted from the output optical port 16.

[0065] As shown in FIG4 , the silicon photonic chip 2 of the embodiment of the present invention is provided with an emitter 24. After an optical signal is input from the input port 11, a portion of the light enters the first input optical port 21, is then transmitted to the emitter 24 of the silicon photonic chip 2 through the first input optical port 21, and is then transmitted to the output optical port 16 provided in the glass conversion waveguide 1 after being acted upon by the emitter 24. It is worth noting that the emitter 24 of the embodiment of the present invention is provided with a modulator 241. After the optical signal is transmitted to the emitter 24 of the silicon photonic chip 2, it is modulated by the modulator 241 so that the modulated optical signal can be transmitted from the output optical port 16. The modulator 241 of the embodiment of the present invention can be, but is not limited to, an MZI modulator. After the optical signal is modulated by the MZI modulator, two signal lights are synthesized. The two signal lights are finally polarization-combined and synthesized into one signal light, which is output from the output optical port 16 of the glass conversion waveguide 1. The number of MZI modulators in the embodiment of the present invention is set according to actual conditions.

[0066] In addition, as shown in Figure 4, one end of the receiver 25 described in an embodiment of the present invention is connected to one end of the second input optical port 22, and the other end of the second input optical port 22 is connected to the signal optical port 17. A mixer 251 is provided in the receiver 25, and the optical signal is transmitted from the second input optical port 22 to the mixer 251 of the receiver 25 to facilitate the conversion of optical and electrical signals.

[0067] The number of mixers 251 in the embodiment of the present invention is set according to actual conditions. For example, the number of mixers 251 can be, but is not limited to, two. The optical signal at the input port 11 is split into two. One portion of the optical signal enters the second optical input port 22, and then is input from the second optical input port 22 into the receiver 25 of the silicon photonic chip 2. After the mixer 251 in the receiver 25 acts, the optical signal is converted into electrical and optical signals. It is worth noting that in the embodiment of the present invention, a balanced detector is usually provided in the receiver 25 during the process of achieving electrical and optical conversion. When the optical signal enters the mixer 251 of the receiver 25, it enters the balanced detector to achieve electrical and optical conversion.

[0068] The coupling between the glass conversion waveguide 1 and the silicon photonic chip 2 in the embodiment of the present invention generally has the following modes. The first mode is that the glass conversion waveguide 1 and the silicon photonic chip 2 are end-face coupled, as shown in FIG5 . Specifically:

[0069] The front face of the glass conversion waveguide 1 is in the same direction as the front face of the silicon photonic chip 2, and the optical port in the glass conversion waveguide 1 and the optical port of the silicon photonic chip 2 are on the same horizontal plane, so that the first positioning mark 15 and the second positioning mark 23 are aligned, so as to facilitate coupling and alignment of the glass conversion waveguide 1 and the silicon photonic chip 2.

[0070] As shown in Figure 5, when the glass conversion waveguide 1 and the silicon photonic chip 2 are end-face coupled, in this structure, the front face of the glass conversion waveguide 1 and the front face of the silicon photonic chip 2 are oriented in the same direction, and their optical ports are coplanar. After an optical signal enters the glass conversion waveguide 1 from input port 11, it is split into two within the glass conversion waveguide 1, outputting through the first and second optical splitting ports 12 and 13 of the glass conversion waveguide 1. These signals then enter the integrated silicon photonic chip 2 through the first and second input optical ports 21 and 22 of the silicon photonic chip 2. This allows light signals greater than 15 dBm to be decomposed by the glass conversion waveguide 1 and then transmitted to the silicon photonic chip 2 at levels significantly lower than 15 dBm. A matching adhesive is placed between the glass conversion waveguide 1 and the silicon photonic chip 2. The matching adhesive has a refractive index between the glass conversion waveguide 1 and the silicon photonic chip 2, further reducing coupling loss and securing the glass conversion waveguide 1 and the silicon photonic chip 2.

[0071] The second method is to couple the glass conversion waveguide 1 and the silicon photonic chip 2 using planar evanescent wave coupling, as shown in FIG6 . Specifically:

[0072] The front face of the glass conversion waveguide 1 faces downward, and the front face of the silicon photonic chip 2 faces upward, so that the first positioning mark 15 is aligned with the second positioning mark 23, so as to facilitate coupling and alignment of the glass conversion waveguide 1 and the silicon photonic chip 2.

[0073] As shown in Figure 6, when the glass conversion waveguide 1 and the silicon photonic chip 2 adopt planar evanescent wave coupling, in this structure, the glass conversion waveguide 1 faces downward, and the end connected to the silicon photonic chip 2 is flipped onto the silicon photonic chip 2. The optical path in the glass conversion waveguide 1 and the optical path of the silicon photonic chip 2 are not on the same plane, and the optical ports of the two are vertically connected. The connected optical ports require a special structural design to facilitate spatial coupling from the glass conversion waveguide 1 to the silicon photonic chip 2.

[0074] The third method is to couple the glass conversion waveguide 1 and the silicon photonic chip 2 by etching, as shown in FIG7 . Specifically:

[0075] A groove matching the glass conversion waveguide 1 is etched on the silicon photonic chip 2, and the glass conversion waveguide 1 is arranged in the groove so that the optical port of the glass conversion waveguide 1 and the optical port of the silicon photonic chip 2 are kept in the same plane and aligned and coupled.

[0076] As shown in FIG7 , when the glass conversion waveguide 1 and the silicon photonic chip 2 are coupled by etching, in this structure, a groove (actually a stepped plane) is etched on the port of the silicon photonic chip 2, and the thinned glass conversion waveguide 1 is directly mounted in the groove of the silicon photonic chip 2. By controlling the height of the groove on the silicon photonic chip 2 and utilizing the first positioning mark 15 in the glass conversion waveguide 1 and the second positioning mark 23 on the silicon photonic chip 2, the optical port of the glass conversion waveguide 1 and the optical port of the silicon photonic chip 2 are kept on the same plane for end-to-end alignment coupling. It is worth noting that the two input lights of the silicon photonic chip 2 in the embodiment of the present invention are usually on the same side at the same time, so only one glass conversion waveguide 1 is needed. If, in special circumstances, the input light is on both sides of the silicon photonic chip 2, glass conversion waveguides 1 can be added on both sides.

[0077] The hybrid integrated structure of glass and silicon photonics in the embodiment of the present invention also has a preferred coupling mode, as shown in Figures 8 and 9. At least four waveguides 18 protruding outward from the end face are provided on the upper portion of the end face on the other side of the glass conversion waveguide 1. The four waveguides 18 are respectively provided at the first splitting optical port 12, the second splitting optical port 13, the output optical port 16 and the signal optical port 17. At least one bump 19 is provided on the lower portion of the end face on the other side of the glass conversion waveguide 1; at least four first receiving grooves 26 recessed into the end face are provided on the upper portion of the end face on one side of the silicon photonic chip 2, and at least one second receiving groove 27 recessed into the end face is provided on the lower portion of the end face on one side of the silicon photonic chip 2; the waveguide 18 matches the first receiving groove 26, and the four waveguides 18 are respectively inserted into the four first receiving grooves 26. The bump 19 matches the second receiving groove 27, and the bump 19 is inserted into the second receiving groove 27, so as to facilitate coupling the glass conversion waveguide 1 and the silicon photonic chip 2 together.

[0078] As shown in Figure 9, in this coupling method, four protruding waveguides 18 are provided on the upper part of the end surface of the glass conversion waveguide 1 of an embodiment of the present invention, and four recessed first receiving grooves 26 are provided on the upper part of the end surface of the silicon photonic chip 2, and the waveguide 18 is inserted into the first receiving groove 26; a bump 19 is provided on the lower part of the end surface of the glass conversion waveguide 1, and a second receiving groove 27 is provided on the lower part of the end surface of the silicon photonic chip 2, and the bump 19 is inserted into the second receiving groove 27; after the waveguide 18 is inserted into the first receiving groove 26 and the bump 19 is inserted into the second receiving groove 27, adhesion coupling is performed by coupling glue. It is worth noting that the number of waveguides 18 provided on the end face of the glass-converted waveguide 1 in this embodiment of the present invention matches the number of input optical ports on one side of the silicon photonic chip 2. For example, when the silicon photonic chip 2 has two input optical ports (a first input optical port 21 and a second input optical port 22), the corresponding number of waveguides 18 is four (always two more than the number of input optical ports). This ensures that after the waveguides 18 are inserted into the corresponding first receiving slots 26, optical signals can be properly transmitted. Furthermore, the number of bumps in this embodiment of the present invention is the same as the number of second receiving slots, with at least one provided. For example, the number can be, but is not limited to, three.

[0079] Compared with the aforementioned coupling modes of the glass conversion waveguide 1 and the silicon photonic chip 2, this coupling mode is provided with coupling glue on the upper and lower parts of the end face of the glass conversion waveguide 1 respectively. When the glass and silicon photonic coupling integrated structure of the embodiment of the present invention is in use, it can avoid the warping of the coupling between the glass conversion waveguide 1 and the silicon photonic chip 2 caused by thermal expansion and contraction (in other coupling modes, the thermal expansion and contraction of the coupling glue causes warping between the glass conversion waveguide 1 and the silicon photonic chip 2, which has a certain impact on the transmission of the glass and silicon photonic coupling integrated structure of the embodiment of the present invention. In addition, it is worth noting that in this coupling mode, the glass conversion waveguide 1 and the silicon photonic chip 2 are set to have equal thickness (the thickness of the side is the same); while in the aforementioned coupling modes of the glass conversion waveguide 1 and the silicon photonic chip 2, the thickness of the glass conversion waveguide 1 is usually smaller than that of the silicon photonic chip 2.

[0080] In the embodiment of the present invention, a glass conversion waveguide 1 is coupled with a silicon photonic chip 2. The glass conversion waveguide 1 is made of glass and used as the light input waveguide of the entire optical path. This can not only effectively avoid the two-photon effect, but also reduce the mode field mismatch between the silicon waveguide and the external optical path, thereby improving the overall performance of the silicon photonic product.

[0081] Example 2:

[0082] Embodiment 2 of the present invention further provides a method for fabricating a hybrid integrated structure of glass and silicon optical. The method is applicable to the fabrication of the hybrid integrated structure of glass and silicon optical described in Embodiment 1, as shown in FIG10 , and specifically includes:

[0083] Step 201 : aligning the first splitting optical port 12 of the glass conversion waveguide 1 with the first input optical port 21 of the silicon photonic chip 2 , and aligning the second splitting optical port 13 of the glass conversion waveguide 1 with the second input optical port 22 of the silicon photonic chip 2 .

[0084] In the process of manufacturing the hybrid integrated structure of glass and silicon photonics in the embodiment of the present invention, the optical port in the glass conversion waveguide 1 is aligned with the optical port on the silicon photonics chip 2 to facilitate coupling of the glass conversion waveguide 1 with the silicon photonics chip 2. In the actual coupling process, in order to more simply achieve the coupling of the glass conversion waveguide 1 with the silicon photonics chip 2, a first positioning mark 15 is set on the glass conversion waveguide 1, and a second positioning mark 23 is set on the silicon photonics chip 2. The first positioning mark 15 and the second positioning mark 23 are coupled and aligned to achieve coupling and alignment of the glass conversion waveguide 1 with the silicon photonics chip 2. It is worth noting that before aligning the optical port of the glass conversion waveguide 1 with the corresponding optical port of the silicon photonics chip 2, it is necessary to fabricate the corresponding waveguide in the glass conversion waveguide 1 and the corresponding waveguide in the silicon photonics chip 2 in advance, and then align the optical port of the glass conversion waveguide 1 with the optical port of the silicon photonics chip 2 to facilitate coupling of the glass conversion waveguide 1 with the silicon photonics chip 2.

[0085] Step 202: Use matching glue to bond and couple the glass conversion waveguide 1 to the silicon photonic chip 2.

[0086] After the glass conversion waveguide 1 and the silicon photonic chip 2 are aligned, the glass conversion waveguide 1 and the silicon photonic chip 2 are kept stationary and are bonded and coupled with each other using matching glue to realize the production of a hybrid integrated structure of glass and silicon photonics.

[0087] In the embodiment of the present invention, a glass conversion waveguide 1 is coupled with a silicon photonic chip 2. The glass conversion waveguide 1 is made of glass and used as the light input waveguide of the entire optical path. This can not only effectively avoid the two-photon effect, but also reduce the mode field mismatch between the silicon waveguide and the external optical path, thereby improving the overall performance of the silicon photonic product.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hybrid integrated structure of glass and silicon photonics, characterized in that, It includes a glass conversion waveguide (1) and a silicon photonics chip (2); One side of the glass conversion waveguide (1) is provided with an input port (11), and at least a first splitting optical port (12) and a second splitting optical port (13) are provided on the other side of the glass conversion waveguide (1); the input port (11) is respectively connected to the first splitting optical port (12) and the second splitting optical port (13); At least a first input optical port (21) and a second input optical port (22) are provided on one side of the silicon photonics chip (2), the first splitting optical port (12) is coupled to the first input optical port (21), and the second splitting optical port (13) is coupled to the second input optical port (22).

2. The hybrid integrated structure of glass and silicon photonics according to claim 1, wherein The glass conversion waveguide (1) is made of glass; wherein, compared with the material of the silicon photonics chip (2), the glass material has light transmittance. Through laser focusing, the focal energy density is large, and a two-photon polymerization reaction occurs, thereby changing the refractive index at the glass focus.

3. The hybrid integrated structure of glass and silicon photonics according to claim 1, characterized in that, When manufacturing the glass conversion waveguide (1), if a waveguide needs to be formed in the glass, femtosecond laser is used for cold processing, so as to form a printed waveguide inside the glass.

4. The hybrid integrated structure of glass and silicon photonics according to claim 1, wherein The glass conversion waveguide (1) is used to convert the light output from the horizontal end face of the silicon waveguide into vertically upward light output, or convert the light output in the vertical direction of the silicon waveguide into light output from the horizontal end face.

5. The hybrid integrated structure of glass and silicon photonics according to claim 1, characterized in that, An optical splitter (14) is provided in the glass conversion waveguide (1), and the optical splitter (14) is provided after the input port (11), so as to divide the optical ports in the glass conversion waveguide (1) into a first splitting optical port (12) and a second splitting optical port (13) through the optical splitter (14).

6. The hybrid integrated structure of glass and silicon photonics according to claim 1, wherein A first positioning mark (15) is provided in the glass conversion waveguide (1), and a second positioning mark (23) is provided on the silicon photonics chip (2). When the glass conversion waveguide (1) is coupled with the silicon photonics chip (2), the first positioning mark (15) is aligned with the second positioning mark (23), so as to align and couple the glass conversion waveguide (1) with the silicon photonics chip (2).

7. The hybrid integrated structure of glass and silicon photonics according to claim 1, wherein The input optical power at the input port (11) of the glass conversion waveguide (1) is greater than or equal to 15 dbm.

8. The hybrid integrated structure of glass and silicon photonics according to claim 5, wherein An output optical port (16) and a signal optical port (17) are provided in the glass conversion waveguide (1); The silicon photonics chip (2) further includes a transmitter (24) and a receiver (25). A modulator (241) is provided in the transmitter (24). One end of the transmitter (24) is connected to the first input optical port (21), and the other end of the transmitter (24) is connected to the output optical port (16). The optical signal is introduced into the modulator (241) of the transmitter (24) from the first input optical port (21), so as to modulate the optical signal and output it from the output optical port (16); One end of the receiver (25) is connected to one end of the second input optical port (22), the other end of the second input optical port (22) is connected to the signal optical port (17), and a mixer (251) is arranged in the receiver (25). The optical signal is introduced into the mixer (251) of the receiver (25) from the second input optical port (22) to facilitate the conversion of optical and electrical signals.

9. The hybrid integrated structure of glass and silicon photonics according to claim 6, wherein, The glass conversion waveguide (1) and the silicon optical chip (2) adopt end-face coupling. Specifically: The front face of the glass conversion waveguide (1) is in the same direction as the front face of the silicon optical chip (2), and the optical ports in the glass conversion waveguide (1) and the silicon optical chip (2) are on the same horizontal plane, so as to align through the first positioning mark (15) and the second positioning mark (23) to facilitate the coupling alignment of the glass conversion waveguide (1) and the silicon optical chip (2).

10. The hybrid integrated structure of glass and silicon photonics according to claim 6, characterized in that, The glass conversion waveguide (1) and the silicon optical chip (2) adopt planar evanescent wave coupling. Specifically: The front face of the glass conversion waveguide (1) faces downward, and the front face of the silicon optical chip (2) faces upward, so as to align through the first positioning mark (15) and the second positioning mark (23) to facilitate the coupling alignment of the glass conversion waveguide (1) and the silicon optical chip (2).

11. The hybrid integrated structure of glass and silicon photonics according to claim 1, characterized in that The glass conversion waveguide (1) and the silicon optical chip (2) adopt etching for coupling. Specifically: A groove matching the glass conversion waveguide (1) is etched on the silicon optical chip (2), and the glass conversion waveguide (1) is arranged in the groove so that the optical ports of the glass conversion waveguide (1) and the silicon optical chip (2) are aligned and coupled on the same plane.

12. The hybrid integrated structure of glass and silicon photonics according to claim 8, characterized in that, On the upper part of the other end face of the glass conversion waveguide (1), at least four waveguides (18) protruding outward from the end face are provided. The four waveguides (18) are respectively arranged at the first splitting optical port (12), the second splitting optical port (13), the output optical port (16) and the signal optical port (17). At least one bump (19) is provided at the lower part of the other end face of the glass conversion waveguide (1); On the upper part of one end face of the silicon optical chip (2), at least four first receiving grooves (26) recessed inward from the end face are provided. At least one second receiving groove (27) recessed inward from the end face is provided at the lower part of one end face of the silicon optical chip (2); The waveguides (18) match the first receiving grooves (26), and the four waveguides (18) are respectively inserted into the four first receiving grooves (26). The bump (19) matches the second receiving groove (27), and the bump (19) is inserted into the second receiving groove (27) to facilitate coupling the glass conversion waveguide (1) and the silicon optical chip (2) together.

13. A manufacturing method of a hybrid integrated structure of glass and silicon photonics, characterized in that, The manufacturing method is used to manufacture the hybrid integrated structure of glass and silicon optical as described in any one of claims 1-9, and includes: Align the first splitting optical port (12) of the glass conversion waveguide (1) with the first input optical port (21) of the silicon photonics chip (2), and align the second splitting optical port (13) of the glass conversion waveguide (1) with the second input optical port (22) of the silicon photonics chip (2); Bond and couple the glass conversion waveguide (1) and the silicon photonics chip (2) using a matching adhesive.

14. The manufacturing method of the hybrid integrated structure of glass and silicon photonics according to claim 13, characterized in that, The refractive index of the glass in the glass conversion waveguide (1) is between 1.470 and 1.700, and the refractive index of the silicon photonics chip 2 is 3.42; adjust the refractive index of the glass conversion waveguide (1) by adjusting the femtosecond laser focusing energy, and adjust the mode fields at both ends of the glass conversion waveguide (1) by adjusting the size and structure of the glass conversion waveguide (1).

15. The manufacturing method of the hybrid integrated structure of glass and silicon photonics according to claim 13, characterized in that, Form an in-fan-out type waveguide in the glass of the glass conversion waveguide (1) through laser 3D printing technology to achieve the matching of the coupling space between the silicon waveguide and different external media.

16. The manufacturing method of the hybrid integrated structure of glass and silicon photonics according to claim 13, wherein, When the optical signal input from the input port (11) is 18 dbm, after the action of the optical splitter (14), the optical signals transmitted from the first splitting optical port (12) and the second splitting optical port (13) are both less than 15 dbm.

17. The manufacturing method of the hybrid integrated structure of glass and silicon photonics according to claim 13, characterized in that, The glass conversion waveguide (1) has at least one level of splitting structure. When the input optical power is greater than 18 dbm, the glass conversion waveguide (1) is made into a two-level splitting structure.

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