An on-chip multi-physics field control device

Abstract

The present invention provides an on-chip multi-physical field control device, including a signal generator, a light source and a heterogeneous integrated optical modulator, wherein the signal generator and the light source are respectively connected to the heterogeneous integrated optical modulator, the signal generator outputs a modulated electrical signal to the heterogeneous integrated optical modulator, the light source outputs an optical carrier to the heterogeneous integrated optical modulator, the heterogeneous integrated optical modulator includes an electrode layer, an optical waveguide layer and an electro-optical material layer, the electro-optical material layer covers the surface of the optical waveguide layer, the electrode layer is arranged on the surface of the electro-optical material layer, a micro-nano structure-based gap structure for limiting the optical carrier is arranged in the optical waveguide layer, and the refractive index of the electro-optical material layer is lower than the refractive index of the optical waveguide layer. The control device is compatible with existing micro-nano processing technology in terms of technology, can integrate the advantages of multi-medium materials, and the gap structure based on the micro-nano structure in terms of structure can enhance the interaction between the optical carrier, the modulated electrical signal and the electro-optical material, and improve the modulation efficiency and bandwidth performance of the electro-optical modulator.

Description

Technical Field

[0001] The present invention belongs to the field of chips, and in particular relates to an on-chip multi-physical field control device. Background Art

[0002] With the development of data centers and optical communications, data traffic has shown explosive growth. It is particularly important to study a new generation of on-chip optical modulators with ultra-bandwidth and high modulation efficiency. Traditional modulators based on lithium niobate materials are limited by the low electro-optic coefficient of lithium niobate itself. The size of the device is generally in the order of centimeters, which is very challenging for large-scale integration and also increases the cost of on-chip optical modulator equipment. With the development of silicon-based photonics, people have begun to explore the realization of optical modulators on silicon. However, since silicon materials themselves are centrosymmetric crystals and lack second-order nonlinear effects, most of the current silicon-based electro-optic modulators are based on plasma dispersion effects, which change the refractive index of silicon materials by regulating the concentration of carriers. However, the modulation rate and modulation bandwidth of this modulation mechanism are limited by the carrier lifetime, and it is difficult to achieve single phase modulation.

[0003] Common design schemes for multi-physical field regulation include: gap waveguide heterointegrated optical modulator, subwavelength grating waveguide heterointegrated optical modulator, and surface plasmon-dielectric heterointegrated optical modulator. In this scheme, the gap waveguide heterointegrated optical modulator will greatly reduce its ability to restrict the optical carrier as the gap width increases. Reducing the width of the gap waveguide will also bring challenges to the production. At the same time, the gap waveguide has a low tolerance for production errors. The subwavelength grating waveguide heterointegrated optical modulator can diffuse the optical carrier into the electro-optical material, but the polarization efficiency of the electro-optical material between the dielectric blocks is low. At the same time, the spacing between the electrodes increases, which reduces the modulation efficiency of the optical modulator. The surface plasmon structure-dielectric heterointegrated optical modulator can strongly constrain the optical carrier on the surface of the metal and interact strongly with the electro-optical material, but the overall optical loss of the device is large. Summary of the invention

[0004] The purpose of the present invention is to provide an on-chip multi-physical field control device, aiming to solve the problem of low modulation efficiency of existing electro-optical modulators.

[0005] The present invention is implemented as follows: an on-chip multi-physical field control device includes a signal generator, a light source and a heterogeneous integrated optical modulator, wherein the signal generator and the light source are respectively connected to the heterogeneous integrated optical modulator, the signal generator outputs a modulated electrical signal to the heterogeneous integrated optical modulator, the light source outputs an optical carrier to the heterogeneous integrated optical modulator, the heterogeneous integrated optical modulator includes an electrode layer, an optical waveguide layer and an electro-optical material layer, the electro-optical material layer covers the surface of the optical waveguide layer, the electrode layer is arranged on the surface of the electro-optical material layer, a micro-nano structure-based gap structure for limiting the optical carrier is arranged in the optical waveguide layer, and the refractive index of the electro-optical material layer is lower than the refractive index of the optical waveguide layer.

[0006] A further technical solution of the present invention is: the optical waveguide layer includes an input light unit, a modulation unit and an output light unit, the input end of the input light unit is connected to the light source, the output end of the input light unit is connected to the input end of the modulation unit, and the input end of the output light unit is connected to the output end of the modulation unit.

[0007] A further technical solution of the present invention is: the modulation unit includes an electrical connection structure and a gap structure, the gap structure includes a first waveguide block and a second waveguide block, the electrical connection structure includes a first electrical connection block and a second electrical connection block for accessing the modulated electrical signal, the first waveguide block is vertically arranged at one end of the first electrical connection block, the second waveguide block is vertically arranged at one end of the second electrical connection block and is arranged close to the first waveguide block, and the first waveguide block and the second waveguide block are arranged opposite to each other.

[0008] A further technical solution of the present invention is: a nanogap is formed between the first waveguide block and the second waveguide block, the nanogap is filled with an electro-optical material with a low refractive index, and the optical carrier is transmitted in the nanogap.

[0009] A further technical solution of the present invention is that the surface of the electrical connection structure is provided with holes for adjusting the overall refractive index of the medium.

[0010] A further technical solution of the present invention is that the shape of the hole is circular, rectangular or diamond-shaped.

[0011] A further technical solution of the present invention is that the overall equivalent refractive index of the electrical connection structure is smaller than the refractive index of the gap structure material.

[0012] A further technical solution of the present invention is that the electro-optical material layer is made of electro-optical polymer material.

[0013] The beneficial effects of the present invention are as follows: the multi-physical field control device proposed in the present invention is compatible with existing micro-nano processing technologies in terms of technology, can integrate the advantages of multi-medium materials, and the gap structure based on the micro-nano structure can enhance the interaction between the optical carrier, the modulated electrical signal and the electro-optical material, thereby improving the modulation efficiency and bandwidth performance of the electro-optical modulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure provided by an embodiment of the present invention;

[0015] Figure 2 is a cross-sectional view of a heterogeneous integrated optical modulator provided by an embodiment of the present invention;

[0016] Figure 3 is a cross-sectional view of a modulation unit provided by an embodiment of the present invention;

[0017] Figure 4 This is the first embodiment of the modulation unit provided in the embodiment of the present invention;

[0018] Figure 5 This is a second embodiment of the modulation unit provided in an embodiment of the present invention;

[0019] Figure 6 This is a third embodiment of the modulation unit provided in the embodiment of the present invention;

[0020] Figure 7 is a comparison diagram of the modulation efficiency of the conventional void waveguide structure and the void waveguide based on the micro-nano structure of the present invention;

[0021] Figure 8 This is a data comparison diagram of the light field confinement capabilities of the conventional void waveguide structure and the void waveguide based on the micro-nano structure of the present invention;

[0022] Fig. 9 This is a data comparison chart of the light field binding ability of the thickness of the traditional void waveguide structure and the thickness of the void waveguide based on the micro-nano structure of the present invention. DETAILED DESCRIPTION

[0023] Figure numerals: 1-input light unit, 2-modulation unit, 3-output light unit, 4-electrode layer, 5-waveguide layer, 6-electro-optical material layer, 7-gap structure, 8-first electrical connection block, 9-first waveguide block, 10-second waveguide block, 11-second electrical connection block, 12-hole.

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "bottom surface" and "top surface", "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0025] Figure 1 An on-chip multi-physical field control device provided by the present invention is shown, comprising a signal generator, a light source and a heterogeneous integrated optical modulator, wherein the signal generator and the light source are respectively connected to the heterogeneous integrated optical modulator, the signal generator outputs a modulated electrical signal to the heterogeneous integrated optical modulator, the light source outputs an optical carrier to the heterogeneous integrated optical modulator, the heterogeneous integrated optical modulator comprises an electrode layer 4, an optical waveguide layer 5 and an electro-optical material layer 6, the electro-optical material layer 6 covers the surface of the optical waveguide layer 5, the electrode layer 4 is arranged on the surface of the electro-optical material layer 6, a micro-nano structure-based gap structure 7 for limiting the optical carrier is arranged in the optical waveguide layer 5, and the refractive index of the electro-optical material layer 6 is lower than the refractive index of the optical waveguide layer 5.

[0026] Preferably, the optical waveguide layer 5 includes an input light unit 1, a modulation unit 2 and an output light unit 3, the input end of the input light unit 1 is connected to the light source, the output end of the input light unit 1 is connected to the input end of the modulation unit 2, and the input end of the output light unit 3 is connected to the output end of the modulation unit 2.

[0027] Preferably, the modulation unit 2 includes an electrical connection structure and a gap structure 7, the gap structure 7 includes a first waveguide block 9 and a second waveguide block 10, the electrical connection structure includes a first electrical connection block 8 and a second electrical connection block 11 for accessing the modulated electrical signal, the first waveguide block 9 is vertically arranged at one end of the first electrical connection block 8, the second waveguide block 10 is vertically arranged at one end of the second electrical connection block 11 and is arranged close to the first waveguide block 9, and the first waveguide block 9 and the second waveguide block 10 are arranged opposite to each other.

[0028] Preferably, a nanogap is formed between the first waveguide block 9 and the second waveguide block 10 , the nanogap is filled with an electro-optic material with a low refractive index, and the optical carrier is transmitted in the nanogap.

[0029] Preferably, the surface of the electrical connection structure is provided with holes 12 for adjusting the overall refractive index of the medium.

[0030] Preferably, the hole 12 has a circular, rectangular or diamond shape.

[0031] Preferably, the overall equivalent refractive index of the electrical connection structure is smaller than the refractive index of the material of the void structure 7 .

[0032] Preferably, the electro-optic material layer 6 is made of electro-optic polymer material.

[0033] The present invention provides an on-chip multi-physics field control device, which can realize simultaneous control and local enhancement of physical fields such as optical field, electric field, and acoustic field on the chip, breaking through the limitation that the traditional photonic device structure can only control a single physical field, thereby improving the performance of multi-physics field photonic devices such as on-chip heterogeneous integrated modulators, multi-dimensional sensors, and photoacoustic converters. The method proposed in the present invention can be widely used in the design of multi-physics field devices, and the applicable fields include:

[0034] (1) High-performance heterogeneous integrated photonic devices, such as ultra-high-speed modulators, all-optical switches, photonic quantum devices, photoacoustic devices, etc.;

[0035] (2) Multidimensional sensors, such as electromagnetic field sensors, photocatalytic detection, etc.

[0036] Taking the application in ultra-high-speed modulators as an example, the on-chip multi-physical field control device proposed in the present invention comprises: the optical waveguide layer 5, the electro-optical material layer 6 and the electrode layer 4. The optical waveguide layer 5 comprises the gap structure 7 based on micro-nano structure, which constrains the transmitted optical signal in the electro-optical material; the electro-optical material layer 6 is heterogeneously integrated on the surface of the optical waveguide layer 5; the electrode layer 4 is processed on the surface of the electro-optical material layer 6, and the electrode layer 4 loads the modulated signal to the area of ​​the electro-optical material layer 6 through a conductive medium or a doped dielectric layer. The multi-physical field control device proposed in the present invention is compatible with the existing micro-nano processing technology in terms of process, and can integrate the advantages of multi-medium materials. The gap structure 7 based on micro-nano structure in structure can enhance the interaction between the optical carrier, the modulated electrical signal and the electro-optical material, and improve the modulation efficiency and bandwidth performance of the electro-optical modulator.

[0037] The present invention proposes that a multi-physics field control device is applied to the configuration of an ultra-high-speed modulator such as Figure 1 As shown, the modulated signal is efficiently encoded onto the optical carrier through the heterogeneous integrated optical modulator, and the optical carrier carries the transmission information after passing through the heterogeneous integrated optical modulator. The heterogeneous integrated optical modulator is composed of the optical waveguide layer 5, the electro-optical material layer 6 and the electrode layer 4, as shown in FIG. Figure 2 As shown, the optical waveguide layer 5 includes the input optical unit 1, the modulation unit 2 based on the micro-nano structure and the output optical unit 3, wherein the input optical unit 1 transmits the optical signal to the modulation unit 2 with low loss. The modulation unit 2 based on the micro-nano structure is composed of the electrical connection structure and the gap structure 7 of the micro-nano structure, wherein the cross section of the gap structure 7 based on the micro-nano structure is as shown in FIG. Figure 3As shown, each of the modulation units 2 includes the first electrical connection block 8, the second electrical connection block 11, the first waveguide block 9 and the second waveguide block 10, wherein the first waveguide block 9 and the first electrical connection block 8 are combined to form an L-shape, the second waveguide block 10 and the second electrical connection block 11 are combined to form an L-shape, the nanogap is formed between the first waveguide block 9 and the second waveguide block 10, and light is transmitted in the nanogap. The holes 12 are provided on the first electrical connection block 8 and the second electrical connection block 11, and the holes 12 can be circular hole structures, rectangular hole structures, or polygonal diamond structures, as shown in FIG. Figure 4 , 5 As shown in , 6, by designing the hole 12 of the micro-nano structure, the refractive index of the electrical connection structure can be adjusted. When the equivalent refractive index of the electrical connection structure is less than the refractive index of the dielectric material of the void structure 7, more optical signals are restricted to be transmitted in the nano-gap. The restriction effect of the nano-gap based on the micro-nano structure on the optical carrier is enhanced, thereby enhancing the interaction between the optical carrier, the modulated electrical signal, and the electro-optical material, such as Figure 7 As shown, the modulation efficiency of the heterogeneous integrated optical modulator is effectively improved. The output optical unit 3 outputs the modulated optical carrier signal to the transmission optical path.

[0038] The materials constituting the optical waveguide layer 5 are mostly based on silicon materials or other high refractive index light transparent materials. The electro-optic material layer 6 covers the surface of the optical waveguide layer 5 and is heterogeneously integrated with the waveguide medium material of the optical waveguide layer 5. It can combine the advantages of both waveguide medium materials and electro-optical materials, and can not only utilize mature micro-nano processing technology, but also achieve high-efficiency phase change regulation at low cost. The refractive index of the electro-optic material layer 6 is generally lower than that of the optical waveguide layer 5, and the electro-optic material is generally composed of electro-optic polymer materials. The electrode layer 4 is used to transmit the modulated electrical signal to the electro-optic material layer 6, and is arranged on the surface of the electro-optic material layer 6. The electrode layer 4 loads the modulated signal to the electro-optic material layer 6 through a conductive medium or a doped dielectric layer.

[0039] In order to quantify the interaction between the optical carrier, the modulated electrical signal, and the electro-optical material, the field interaction factor Γ is defined slot,x (Field interaction factor) is:

[0040]

[0041] in is the x-component of the electric field perpendicular to the transmission direction in the void waveguide, and are the electric field intensity and magnetic field intensity of the transmission cross section respectively.

[0042] The field interaction factor Γ slot,x For the optimization purpose, the gap waveguide structure parameters: the width W of the silicon track rail , the width W of the gap waveguide slot , the thickness of the electrical connection dielectric layer H slab , the equivalent refractive index n of the micro-nanostructure slab For optimizing variables, the results are as follows Figure 8 , 9 shown.

[0043] from Figure 8 It can be concluded that, in the gap waveguide width W slot When changing from 100nm to 200nm, the field interaction factor Γ of the traditional gap waveguide structure slot,x The field interaction factor Γ of the void-waveguide structure without electrical connection is less than 0.225. slot,x The field interaction factor Γ is between 0.325 and 0.375, which indicates that the presence of doped dielectric junctions will reduce the ability of the void waveguide to confine the optical field. slot,x As the width W of the gap waveguide slot Reducing the width of the gap waveguide can slightly weaken this effect. However, too small a width of the gap waveguide will significantly reduce the actual polarization efficiency in the device, increase the capacitance C formed by the gap waveguide, and also increase the complexity of the etching process.

[0044] The micro-nanostructure-based void structure 7 proposed in the present invention can effectively improve the problem of reduced light field confinement capability after the traditional void waveguide is connected by introducing doped dielectrics. Figure 8 The simulation results show that the field interaction factor Γ slot,x Between 0.325 and 0.375, at the same time, when W rail When changing from 200nm to 240nm, the field interaction factor Γ slot,x The variation range is very small, which shows that the structure has a high tolerance for manufacturing errors.

[0045] Fig. 9 It is shown that when the gap waveguide structure parameters are: W slot =120nm,W rail = 220nm, the field interaction factor Γ slot,x With the thickness of the electrical connection dielectric layer H slab Thickness H slab When the nanostructure changes from 10nm to 100nm, the field interaction factor Γ of the void waveguide structure with doped electrically connected dielectric layer is slot,x Will follow H slab The increase of H significantly attenuates, while the micro-nanostructure-based void structure 7 proposed in the present invention decreases with the increase of Hslab The increase of Γ slightly attenuates, but the overall slot,x Maintained at around 0.35, it can be seen that the gap structure 7 based on the micro-nano structure does not need to be processed to a very thin thickness, which reduces the complexity of micro-nano device processing, while also reducing the resistance of the electrical connection area and improving the bandwidth performance of the heterogeneous integrated optical modulator.

[0046] The device greatly improves the modulation efficiency of the electro-optic modulator by enhancing the interaction between the light field, the electric field and the electro-optic material. The simple geometric structure of the micro-nanostructured gap structure 7 has a high tolerance for manufacturing errors and can effectively reduce the complexity of the micro-nano processing process.

[0047] 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 protection scope of the present invention.

Claims

1. An on-chip multi-physics field control device, characterized in that: The invention comprises a signal generator, a light source and a heterogeneous integrated optical modulator, wherein the signal generator and the light source are respectively connected to the heterogeneous integrated optical modulator, the signal generator outputs a modulated electrical signal to the heterogeneous integrated optical modulator, the light source outputs an optical carrier to the heterogeneous integrated optical modulator, the heterogeneous integrated optical modulator comprises an electrode layer, an optical waveguide layer and an electro-optical material layer, the electro-optical material layer covers the surface of the optical waveguide layer, the electrode layer is arranged on the surface of the electro-optical material layer, a micro-nano structure-based gap structure for limiting the optical carrier is arranged in the optical waveguide layer, and the refractive index of the electro-optical material layer is lower than the refractive index of the optical waveguide layer; the optical waveguide layer comprises an input optical unit, a modulation unit and an output optical unit, the input end of the input optical unit is connected to the light source, the output end of the input optical unit is connected to the input end of the modulation unit, the input end of the output optical unit is connected to the The output end of the modulation unit is connected; the modulation unit includes an electrical connection structure and a gap structure, the gap structure includes a first waveguide block and a second waveguide block, the electrical connection structure includes a first electrical connection block and a second electrical connection block for accessing a modulated electrical signal, the first waveguide block is vertically arranged at one end of the first electrical connection block, the second waveguide block is vertically arranged at one end of the second electrical connection block and is arranged close to the first waveguide block, and the first waveguide block and the second waveguide block are arranged opposite to each other; the first waveguide block and the first electrical connection block are combined to form an L shape, and the second waveguide block and the second electrical connection block are combined to form an L shape; a nanogap is formed between the first waveguide block and the second waveguide block, the nanogap is filled with an electro-optical material with a low refractive index, and the optical carrier is transmitted in the nanogap; the surface of the electrical connection structure is provided with a hole for regulating the overall refractive index of the medium.

2. The on-chip multi-physics field control device according to claim 1, characterized in that: The hole is in the shape of a circle, a rectangle or a diamond.

3. The on-chip multi-physics field control device according to claim 1, characterized in that: The overall equivalent refractive index of the electrical connection structure is smaller than the refractive index of the void structure material.

4. The on-chip multi-physics field control device according to claim 1, characterized in that: The electro-optic material layer is made of electro-optic polymer material.

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