Waveguide modulator and waveguide modulator fabrication method

Abstract

The application provides a waveguide modulator and a preparation method of the waveguide modulator. The waveguide modulator comprises a first waveguide layer, a second waveguide layer and a lithium niobate layer. The lithium niobate layer is bonded between the first waveguide layer and the second waveguide layer. The waveguide modulator provided by the application has the optical field phase control performance of low half-wave voltage-length product, high modulation rate and low insertion loss.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optoelectronic information technology, and in particular to a waveguide modulator and a waveguide modulator preparation method. BACKGROUND

[0002] The waveguide modulator is a key device in an optoelectronic information processing system, and has broad application prospects in the fields of optical communication, optical computing and optical quantum.

[0003] According to the related art, the integrated waveguide modulator can improve the refractive index difference, enhance the light field restriction and achieve high-speed modulation of hundreds of GHz, but the half-wave voltage-length product is still in the order of several V·cm. Therefore, it is still very difficult to integrate a large number of modulators on a chip for the scene. SUMMARY

[0004] The present application provides a waveguide modulator and a waveguide modulator preparation method, which realizes the optical field phase control performance of the waveguide modulator with low half-wave voltage-length product, high modulation rate and low insertion loss.

[0005] The present application provides a waveguide modulator, comprising: a first waveguide layer, a second waveguide layer and a lithium niobate layer; wherein the lithium niobate layer is bonded between the first waveguide layer and the second waveguide layer.

[0006] According to the present application, the first waveguide layer and the second waveguide layer comprise a semiconductor material.

[0007] According to the present application, the first waveguide layer and the second waveguide layer comprise silicon material or germanium material.

[0008] According to the present application, the first waveguide layer comprises P-type doped silicon material, and the second waveguide layer comprises N-type doped silicon material; or the first waveguide layer comprises N-type doped silicon material, and the second waveguide layer comprises P-type doped silicon material.

[0009] According to the present application, the thickness of the lithium niobate layer is 50nm-300nm.

[0010] The application further provides a preparation method of a waveguide modulator.

[0011] According to the preparation method of the waveguide modulator, after the lithium niobate layer is transferred to the first waveguide layer based on the bonding mode, the method further comprises: thinning the lithium niobate layer, so that the layer thickness of the thinned lithium niobate layer is 50-300 nm.

[0012] According to the preparation method of the waveguide modulator, the first waveguide layer comprises P-doped silicon material, and the second waveguide layer comprises N-doped silicon material; the first waveguide layer is prepared by the following method: obtaining a first silicon substrate, and performing P-doping treatment on the first silicon substrate to obtain the first waveguide layer; the second waveguide layer is formed by the following method: forming a second silicon substrate by deposition or bonding; performing N-doping treatment on the second silicon substrate to obtain the second waveguide layer.

[0013] According to the preparation method of the waveguide modulator, the first waveguide layer comprises N-doped silicon material, and the second waveguide layer comprises P-doped silicon material; the first waveguide layer is prepared by the following method: obtaining a first silicon substrate, and performing N-doping treatment on the first silicon substrate to obtain the first waveguide layer; the second waveguide layer is formed by the following method: forming a second silicon substrate by deposition or bonding; performing P-doping treatment on the second silicon substrate to obtain the second waveguide layer.

[0014] The application further provides a preparation method of a waveguide modulator, which is applied to the preparation of the waveguide modulator, and comprises the following steps: obtaining a lithium niobate layer; and forming a first waveguide layer and a second waveguide layer on two sides of the lithium niobate layer based on deposition treatment.

[0015] According to the preparation method of the waveguide modulator, the step of obtaining the lithium niobate layer comprises the following steps: obtaining a wafer plane; and processing the wafer plane based on etching to obtain the lithium niobate layer with a layer thickness of 50-300 nm.

[0016] The application provides a waveguide modulator preparation method based on deposition treatment, and first and second waveguide layers are formed on two sides of the lithium niobate layer, and the method specifically comprises the following steps: forming initial first and second waveguide layers on two sides of the lithium niobate layer based on amorphous silicon deposition treatment; performing P-type doping treatment on the initial first waveguide layer and N-type doping treatment on the initial second waveguide layer; or performing N-type doping treatment on the initial first waveguide layer and P-type doping treatment on the initial second waveguide layer, so as to form the first and second waveguide layers on two sides of the lithium niobate layer, respectively.

[0017] The application provides a waveguide modulator and a waveguide modulator preparation method, wherein the waveguide modulator is composed of a first waveguide layer, a second waveguide layer and a lithium niobate layer, and the lithium niobate layer is bonded between the first waveguide layer and the second waveguide layer. By constructing a slit waveguide modulator structure of the first waveguide layer-lithium niobate layer-second waveguide layer, the waveguide modulator can have low half-wave voltage-length product, high modulation rate and low insertion loss of optical field phase control performance. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0019] Figure 1 FIG. 1 is a structural schematic diagram of the waveguide modulator provided by the application;

[0020] Figure 2 FIG. 2 is a structural cross-sectional schematic diagram of the waveguide modulator provided by the application;

[0021] Figure 3 FIG. 3 is a schematic diagram of the relationship between the half-wave voltage-length product and the layer thickness of the lithium niobate layer based on the waveguide modulator provided by the application;

[0022] Figure 4 FIG. 4 is a schematic diagram of the relationship between the phase modulation amount and the voltage of the waveguide modulator with a 40 nm lithium niobate layer thickness provided by the application;

[0023] Figure 5 FIG. 5 is a schematic diagram of the relationship between the phase modulation amount and the voltage of the waveguide modulator with an 80 nm lithium niobate layer thickness provided by the application;

[0024] Figure 6 FIG. 6 is one of the flow schematic diagrams of the waveguide modulator preparation method provided by the application;

[0025] Figure 7 is a preparation process flow chart of the waveguide modulator provided by the present application;

[0026] Figure 8 is a second flow chart of the waveguide modulator preparation method provided by the present application;

[0027] Figure 9 is a structural schematic diagram of the intensity modulator obtained based on the waveguide modulator provided by the present application;

[0028] Figure 10 is a structural schematic diagram of the directional coupler obtained based on the waveguide modulator provided by the present application;

[0029] Reference signs:

[0030] Waveguide modulator: 10; First waveguide layer: 101;

[0031] Second waveguide layer: 102; Lithium niobate layer: 103. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0033] In the drawings, the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0034] In the description of the embodiments, it needs to be understood that the terms "center", "longitudinal", "transverse", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the embodiments. It should be noted that: unless otherwise specified, the relative arrangement of the components, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the application.

[0035] The waveguide modulator provided by the application can construct a slit waveguide modulator structure composed of a first waveguide layer-lithium niobate layer-second waveguide layer, and further ensure that the waveguide modulator has low half-wave voltage-length product, high modulation rate, and low insertion loss of optical field phase control performance.

[0036] Figure 1 is a structural schematic diagram of the waveguide modulator provided by the application, Figure 2 is a structural cross-sectional schematic diagram of the waveguide modulator provided by the application. The waveguide modulator provided by the application will be described below in combination with Figures 1-2

[0037] In an exemplary embodiment of the application, in combination with Figure 1 and Figure 2 It can be seen that the waveguide modulator 10 can include a first waveguide layer 101, a second waveguide layer 102, and a lithium niobate layer 103. The lithium niobate layer 103 is bonded between the first waveguide layer 101 and the second waveguide layer 102. It can be understood that the waveguide modulator 10 can be a slit waveguide modulator structure composed of a first waveguide layer 101-lithium niobate layer 103-second waveguide layer 102.

[0038] It should be noted that the lithium niobate layer 103 can form a slit mode, wherein for the mode field distribution of the waveguide modulator 10, the optical field can be mainly concentrated in the lithium niobate layer 103 with a high electro-optic modulation coefficient (for example, the electro-optic modulation coefficient r 33 ≥ 30 pm / V), and therefore the waveguide modulator 10 can have a higher modulation efficiency.

[0039] The waveguide modulator 10 provided by the application is composed of a first waveguide layer 101, a second waveguide layer 102, and a lithium niobate layer 103, and the lithium niobate layer 103 is bonded between the first waveguide layer 101 and the second waveguide layer 102. By constructing a slit waveguide modulator structure of a first waveguide layer 101-lithium niobate layer 103-second waveguide layer 102, the waveguide modulator 10 can ensure low half-wave voltage-length product, high modulation rate, and low insertion loss of optical field phase control performance.​

[0040] In an exemplary embodiment of the present application, the first waveguide layer 101 and the second waveguide layer 102 can comprise semiconductor materials. In an example, the first waveguide layer 101 and the second waveguide layer 102 can be semiconductor materials with electrical conductivity.

[0041] In an example, the first waveguide layer 101 can be a silicon material or a germanium material.

[0042] In another example, the second waveguide layer 102 can also be a silicon material or a germanium material.

[0043] In an exemplary embodiment of the present application, the first waveguide layer 101 can comprise a P-type doped silicon material, and the second waveguide layer 102 can comprise an N-type doped silicon material; or, the first waveguide layer 101 can comprise an N-type doped silicon material, and the second waveguide layer 102 can comprise a P-type doped silicon material.

[0044] In application, the first waveguide layer 101 and the second waveguide layer 102 employ doped silicon materials, such as N-type doped silicon materials or P-type doped silicon materials, which can avoid severe loss caused by metal electrodes, and at the same time, can reduce the distance between electrodes, so that the modulation electric field intensity in the lithium niobate layer 103 is larger when the same voltage is loaded, and thus a better modulation effect can be obtained.

[0045] In order to better form a slot mode with respect to the lithium niobate layer 103, in an embodiment, the layer thickness of the lithium niobate layer 103 can be set to 50 nm to 300 nm.

[0046] In another example, the phase modulation amount of the waveguide modulator 10 under a unit length voltage can be represented by formula (1):

[0047]

[0048] wherein, Δφ represents the phase modulation amount; λ represents the wavelength of the modulated light; n eff represents the equivalent refractive index of the slot mode (corresponding to the lithium niobate layer 103); r 33 represents the electro-optic modulation coefficient of the lithium niobate layer 103; E microwave represents the modulation electric field distribution generated by the doped silicon electrode under unit voltage loading, wherein the electric field is mainly distributed in the lithium niobate layer 103; E x represents the X component of the optical field; E represents the optical field vector.

[0049] In application, based on formula (1), the relationship between the half-wave voltage-length product based on the waveguide modulator 10 and the layer thickness of the lithium niobate layer 103 can be calculated.

[0050] Figure 3is a schematic view of the relationship between the half-wave voltage-length product obtained by the waveguide modulator provided in the present application and the thickness of the lithium niobate layer.

[0051] The half-wave voltage-length product obtained by the modulator based on the conventional waveguide structure combined with the metal electrode is in the order of several V·cm. Figure 3 It can be seen that, compared with the conventional modulator, the half-wave voltage-length product of the waveguide modulator 10 provided in the present application is reduced by one to two orders of magnitude, and it is expected that the waveguide modulator 10 provided in the present application can greatly reduce the required on-chip area of the modulator and greatly improve the integration, which provides the possibility for solving the large-scale integrated modulator array.

[0052] In an embodiment, under the 1550nm communication waveband, the thickness of the lithium niobate layer 103 is 40nm and 80nm respectively, the width of the first waveguide layer 101 and the second waveguide layer 102 is 300nm, and the relationship between the phase modulation amount and the voltage of the electro-optic phase modulator (corresponding to the waveguide modulator 10) with a length of 1mm is respectively as shown in Figure 4 and Figure 5 .

[0053] It can be seen that, compared with the conventional modulator, the half-wave voltage-length product of the waveguide modulator 10 provided in the present application is reduced by one to two orders of magnitude, and it is expected that the waveguide modulator 10 provided in the present application can greatly reduce the required on-chip area of the modulator and greatly improve the integration, which provides the possibility for solving the large-scale integrated modulator array. Figure 4 and Figure 5 It can be seen that, the waveguide modulator 10 with a slit width of 40nm (corresponding to the thickness of the lithium niobate layer 103 being 40nm) can achieve a smaller half-wave voltage, about 0.7V. And the waveguide modulator 10 with a slit width of 80nm (corresponding to the thickness of the lithium niobate layer 103 being 80nm) can achieve a half-wave voltage of about 1.2V. The corresponding half-wave voltage-length products are 0.07V·cm and 0.12V·cm respectively. Compared with the working half-wave voltage-length product of the existing lithium niobate modulator, it can be reduced by one to two orders of magnitude.

[0054] According to the foregoing description, it can be seen that the waveguide modulator provided in the present application is composed of the first waveguide layer, the second waveguide layer and the lithium niobate layer, and the lithium niobate layer is bonded between the first waveguide layer and the second waveguide layer. By constructing the slit waveguide modulator structure of the first waveguide layer-lithium niobate layer-second waveguide layer, it can ensure that the waveguide modulator has the optical field phase control performance of low half-wave voltage-length product, high modulation rate and low insertion loss.

[0055] The present application further provides a waveguide modulator preparation method. The waveguide modulator preparation method can be applied to the preparation of the waveguide modulator described above.

[0056] Figure 6 is one of the flowcharts of the waveguide modulator preparation method provided in the present application.

[0057] In an exemplary embodiment of the present application, in combination with Figure 6It can be known that the waveguide modulator preparation method can include steps 610 to 630, and each step will be introduced below.

[0058] In step 610, a first waveguide layer is obtained, and a lithium niobate layer is transferred to the first waveguide layer based on a bonding method.

[0059] It should be noted that the lithium niobate layer is transferred to the first waveguide layer based on the bonding method, which can be understood as bonding the lithium niobate layer to the surface of the first waveguide layer.

[0060] In step 620, a second waveguide layer is formed on the other side of the lithium niobate layer relative to the first waveguide layer by deposition or bonding.

[0061] In the application process, since the lithium niobate layer has been bonded to the first waveguide layer, it can be understood that one side of the lithium niobate layer is attached to the first waveguide layer. In this embodiment, a second waveguide layer can be formed on the other side of the lithium niobate layer (i.e., the opposite side of the first waveguide layer) by deposition or bonding, thereby forming a first waveguide layer-lithium niobate layer-second waveguide layer structure of the slit waveguide modulator.

[0062] In step 630, the first waveguide layer and the second waveguide layer are respectively subjected to metal electrode deposition treatment to obtain a waveguide modulator.

[0063] In an exemplary embodiment of the present application, the previous embodiment described above is taken as an example for description. After the lithium niobate layer is transferred to the first waveguide layer based on the bonding method in step 610, the waveguide modulator preparation method can further include: thinning the lithium niobate layer to have a layer thickness of 50nm-300nm. In this embodiment, by setting the layer thickness of the lithium niobate layer to 50nm-300nm, a better slit mode about the lithium niobate layer can be ensured, which lays a foundation for ensuring the optical field phase control performance of the waveguide modulator with low half-wave voltage-length product, high modulation rate, and low insertion loss.

[0064] In still another exemplary embodiment of the present application, the first waveguide layer can include a P-type doped silicon material, and the second waveguide layer can include an N-type doped silicon material.

[0065] The first waveguide layer can be prepared by the following method: obtaining a first silicon substrate and performing P-type doping treatment on the first silicon substrate to obtain the first waveguide layer.

[0066] The second waveguide layer can be formed by the following method: forming a second silicon substrate by deposition or bonding; and performing N-type doping treatment on the second silicon substrate to obtain the second waveguide layer.

[0067] In yet another exemplary embodiment of the present invention, the first waveguide layer may include an N-type doped silicon material, and the second waveguide layer may include a P-type doped silicon material.

[0068] The first waveguide layer can be prepared by obtaining a first silicon substrate and performing N-type doping on the first silicon substrate to obtain the first waveguide layer.

[0069] The second waveguide layer can be formed by deposition or bonding in the following way: a second silicon substrate is formed by deposition or bonding; the second silicon substrate is then subjected to P-type doping to obtain the second waveguide layer.

[0070] In this embodiment, by performing P-type doping or N-type doping on the first waveguide layer and the second waveguide layer, the severe losses introduced by the metal electrode can be avoided, and the electrode spacing can be reduced. As a result, when the same voltage is applied, the modulation electric field strength in the lithium niobate layer is greater, and thus a better modulation effect can be obtained.

[0071] To further introduce the fabrication process of the waveguide modulator provided by this invention, the following will be combined with... Figure 7 Please provide an explanation.

[0072] Figure 7 This is a process flow diagram of the waveguide modulator fabrication process provided by the present invention.

[0073] In an exemplary embodiment of the present invention, combined with Figure 7 As can be seen, a silicon substrate (corresponding to SOI in the diagram) can be obtained first. This silicon substrate can include a SiO2 layer and a crystalline silicon layer (corresponding to c-Si in the diagram). Before bonding the lithium niobate layer (corresponding to the LN layer in the diagram), the silicon substrate can be p-type doped or n-type doped. Then, the lithium niobate layer is transferred to the silicon substrate via bonding. Figure 7 The following explanation uses N-type doping as an example.

[0074] Current lithium niobate layer bonding processes typically only transfer lithium niobate layers with a thickness of 300–900 nm. In this approach, a narrower slit width (corresponding to the LN layer thickness) results in a smaller half-wave voltage-length product. Therefore, the lithium niobate layer needs to be further thinned to 50–300 nm using methods such as argon ion etching (corresponding to LN layer thinning in the diagram, ICP argon ion etching) to achieve better phase modulation.

[0075] Furthermore, a silicon layer of a certain thickness can be deposited or bonded to the lithium niobate layer and then subjected to N-type or P-type doping. Figure 7 The following explanation uses P-type doping as an example.

[0076] Further, the top and bottom doped silicon (corresponding to the first waveguide layer and the second waveguide layer) are respectively subjected to metal electrode deposition to form ohmic contact, thereby realizing the slotted waveguide modulator provided by the present application. In the embodiment, by constructing the slotted waveguide modulator structure of the first waveguide layer-lithium niobate layer-second waveguide layer, the waveguide modulator can have the optical field phase control performance of low half-wave voltage-length product, high modulation rate and low insertion loss.

[0077] The present application further provides another waveguide modulator preparation method. The waveguide modulator preparation method can also be applied to the preparation of the waveguide modulator described above.

[0078] Figure 8 FIG. 2 is a flowchart of the waveguide modulator preparation method provided by the present application.

[0079] In an exemplary embodiment of the present application, the waveguide modulator preparation method can be applied to the preparation of the waveguide modulator described above. Figure 8 It can be seen that the waveguide modulator preparation method can include steps 810 to 820, which will be introduced respectively.

[0080] In step 810, a lithium niobate layer is obtained.

[0081] In an embodiment, the lithium niobate layer can be obtained by the following method:

[0082] A wafer plane is obtained, and the wafer plane is processed based on an etching method to obtain a lithium niobate layer with a thickness of 50-300 nm. It should be noted that the wafer plane can be understood as a lithium niobate material that has not been subjected to thinning treatment.

[0083] In step 820, a first waveguide layer and a second waveguide layer are respectively formed on both sides of the lithium niobate layer based on deposition processing.

[0084] In an embodiment, the first waveguide layer and the second waveguide layer can be respectively formed on both sides of the lithium niobate layer based on deposition processing by the following method:

[0085] The initial first waveguide layer and the initial second waveguide layer are respectively formed on both sides of the lithium niobate layer based on amorphous silicon deposition processing; the initial first waveguide layer is subjected to P-type doping processing and the initial second waveguide layer is subjected to N-type doping processing, or the initial first waveguide layer is subjected to N-type doping processing and the initial second waveguide layer is subjected to P-type doping processing, so as to respectively form the first waveguide layer and the second waveguide layer on both sides of the lithium niobate layer.

[0086] In application, the structure of the lithium niobate layer can be defined within the wafer plane (corresponding to the unthinned lithium niobate material). First, a lithium niobate layer with a slit structure, with a thickness of 50nm to 300nm, needs to be fabricated on a lithium niobate platform on an insulator using physical or chemical etching. Then, amorphous silicon deposition is performed to obtain the initial first waveguide layer and the initial second waveguide layer. Further, the silicon on both sides of the lithium niobate layer (corresponding to the initial first and second waveguide layers) is subjected to P-type and N-type doping treatments, respectively, to obtain the slit-structured waveguide modulator provided by this invention. In this embodiment, by constructing a slit waveguide modulator structure of a first waveguide layer-lithium niobate layer-second waveguide layer, the waveguide modulator can be ensured to have low half-wave voltage-length product, high modulation rate, and low insertion loss optical field phase modulation performance.

[0087] In one example, based on the waveguide modulator provided by this invention, an intensity modulator can be constructed using a Mach-Zehnder interferometer. The structure of the intensity modulator is as follows: Figure 9 As shown.

[0088] Combination Figure 9 As can be seen, the incident light is split into two arms by the Y-branch (corresponding to E in the diagram). in In the direction shown, and finally along E out (Emitted in the direction shown). Both the upper and lower arms employ the slit-type waveguide modulator proposed in this invention, and are equipped with push-pull electrode structures.

[0089] In application, the electric fields applied to the two arms are in opposite directions, thus the signs of the phase modulation are opposite, thereby halving the half-wave voltage-length product required for extinction. Considering the typical output voltage of 3.4V for transistor-transistor logic (TTL) and 1.2V for complementary metal-oxide-semiconductor (CMOS), the calculated device dimensions are shown in Table 1 below. The results show that this architecture can effectively reduce the size of the on-chip intensity modulation device.

[0090] Table 1 Device dimensions of intensity modulators with different lithium niobate layer thicknesses

[0091] Layer thickness of the lithium niobate layer CMOS typical voltage (1.2 V) TTL typical voltage (3.4 V) 40 nm 292 μm 103 μm 80 nm 500 μm 176 μm

[0092] High-speed, large-scale optical switch has important significance for optical communication and data center application fields, and the directional coupler is a key device for constructing a large-scale optical switch array. In another example, based on the waveguide modulator provided in the present application, a directional coupler can be constructed. The structure of the directional coupler is as shown in Figure 10 The incident light path of the optical wave is realized through the waveguide modulator, in Figure 10 , the optical wave enters in the direction of E in1 , exits in the direction of E out1 , enters in the direction of E in2 , and exits in the direction of E out2 .

[0093] In the application process, the working principle of the directional coupler is to change the output port of the optical signal by regulating the refractive index difference of the symmetric mode and the antisymmetric mode. However, the phase modulation length required by the traditional silicon-based and lithium niobate device is large, and it is difficult to achieve large-scale integration. The coupling waveguide spacing of the directional coupler designed based on the waveguide modulator provided in the present application is 100 nm, and the slit width (corresponding to the thickness of the rear layer of the lithium niobate layer) is 50 nm. Under the application of a unit voltage, the refractive index difference is 5.7x10 -4 / V. Therefore, the voltage-length product required for switching the output port can be calculated as 1.36V·mm. That is, for a directional coupler with a coupling waveguide length of 1mm, the voltage required for switching from the straight-through port to another port is 1.36V. This result shows that the waveguide modulator provided in the present application has the potential to reduce the size of the on-chip directional coupler.

[0094] Compared with existing waveguide modulators, the waveguide modulator based on the integrated lithium niobate platform provided in the present application can reduce the size by one to two orders of magnitude. The reduction of the length of the modulator can also effectively reduce the time constant and insertion loss of the resistor-capacitor circuit, thereby making large-scale integration of the waveguide modulator provided in the present application possible.

[0095] It can be understood that, although the operations are described in a particular order in the drawings in the embodiments of the present application, it should not be understood as requiring the operations to be performed in the particular order shown or in a serial order, or requiring all the operations to be performed to obtain the desired results. In a particular environment, multitasking and parallel processing can be advantageous.

[0096] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A waveguide modulator, comprising: The waveguide modulator comprises a first waveguide layer, a second waveguide layer and a lithium niobate layer; The lithium niobate layer is arranged between the first waveguide layer and the second waveguide layer by bonding, wherein the thickness of the lithium niobate layer is 50-300 nm, the lithium niobate layer forms a slot mode, and the waveguide modulator is a slot waveguide modulator structure composed of the first waveguide layer-lithium niobate layer-second waveguide layer, wherein the phase modulation amount of the waveguide modulator under unit length voltage is represented by formula (1): where Δφ represents the phase modulation amount; λ represents the wavelength of the modulated light; n eff represents the equivalent refractive index of the lithium niobate layer; r 33 represents the electro-optic modulation coefficient of the lithium niobate layer; E microwave represents the modulation electric field distribution generated by the doped silicon electrode under unit voltage loading, where the electric field is mainly distributed in the lithium niobate layer; E x represents the X component of the optical field; E represents the optical field vector.

2. The waveguide modulator of claim 1, wherein, The first waveguide layer and the second waveguide layer comprise a semiconductor material.

3. The waveguide modulator of claim 2, wherein, The first waveguide layer and the second waveguide layer comprise silicon material or germanium material.

4. The waveguide modulator of claim 3, wherein, The first waveguide layer comprises P-doped silicon material, and the second waveguide layer comprises N-doped silicon material; or The first waveguide layer comprises N-doped silicon material, and the second waveguide layer comprises P-doped silicon material.

5. A method for fabricating a waveguide modulator, characterized in that, The preparation method is applied to the preparation of the waveguide modulator in any one of claims 1-4, and the preparation method comprises: obtaining a first waveguide layer and transferring a lithium niobate layer to the first waveguide layer based on a bonding method; forming a second waveguide layer on the other side of the lithium niobate layer relative to the first waveguide layer by deposition or bonding; respectively performing metal electrode deposition treatment on the first waveguide layer and the second waveguide layer to obtain the waveguide modulator.

6. The method of claim 5, wherein the waveguide modulator is prepared by: After the lithium niobate layer is transferred to the first waveguide layer based on the bonding method, the method further comprises: thinning the lithium niobate layer to a thickness of 50-300 nm.

7. The method of claim 5, wherein the waveguide modulator is prepared by: The first waveguide layer comprises P-doped silicon material, and the second waveguide layer comprises N-doped silicon material; The first waveguide layer is prepared by the following method: obtaining a first silicon substrate and performing P-doping treatment on the first silicon substrate to obtain the first waveguide layer; The second waveguide layer is formed by deposition or bonding, specifically comprising: forming a second silicon substrate by deposition or bonding; performing N-doping treatment on the second silicon substrate to obtain the second waveguide layer.

8. The method of claim 5, wherein: The first waveguide layer comprises N-doped silicon material, and the second waveguide layer comprises P-doped silicon material; The first waveguide layer is prepared by the following method: obtaining a first silicon substrate and performing N-doping treatment on the first silicon substrate to obtain the first waveguide layer; The second waveguide layer is formed by deposition or bonding, specifically comprising: forming a second silicon substrate by deposition or bonding; performing P-doping treatment on the second silicon substrate to obtain the second waveguide layer.

9. A method for fabricating a waveguide modulator, characterized in that, The preparation method is applied to the preparation of the waveguide modulator in any one of claims 1-4, and the preparation method comprises: obtaining a lithium niobate layer; forming a first waveguide layer and a second waveguide layer on both sides of the lithium niobate layer based on deposition treatment.

10. The method of claim 9, wherein: The lithium niobate layer is obtained by the following method: obtaining a wafer plane; performing etching treatment on the wafer plane to obtain the lithium niobate layer with a thickness of 50-300 nm.

11. The method of claim 9, wherein: The deposition-based processing forms a first waveguide layer and a second waveguide layer on two sides of the lithium niobate layer, respectively, and specifically includes: The amorphous silicon deposition-based processing forms an initial first waveguide layer and an initial second waveguide layer on two sides of the lithium niobate layer, respectively. The initial first waveguide layer is subjected to P-type doping processing and the initial second waveguide layer is subjected to N-type doping processing; or The initial first waveguide layer is subjected to N-type doping processing and the initial second waveguide layer is subjected to P-type doping processing to form the first waveguide layer and the second waveguide layer on two sides of the lithium niobate layer, respectively.

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