High-efficiency electro-optical modulator

Abstract

The utility model discloses a high-efficiency electro-optical modulator, which comprises a substrate material, an optical waveguide, a modulation electrode, an etching groove and a cladding, wherein the optical waveguide is positioned on the substrate material; the modulation electrodes are positioned on two sides of the optical waveguide and comprise a signal electrode and a ground electrode; the etching groove is located between the optical waveguide and the modulation electrode; and the cladding covers the optical waveguide, the etching groove and the modulation electrode. According to the high-efficiency electro-optical modulator, the micro-nano technology is optimized to etch the optical waveguide and form the etching grooves on the two sides of the optical waveguide at the same time, the existence of the etching grooves enables the distribution of an optical field in the optical waveguide to be more concentrated, the electrode spacing is allowed to be smaller while the low transmission loss is maintained, the electric field intensity in the optical waveguide is enhanced, and the transmission efficiency of the electro-optical modulator is improved. And the modulation efficiency is improved. Besides, the design also reduces the size of the device, is favorable for realizing high-density integration of a photon chip and miniaturization of a system, and provides a more efficient and more compact solution for the field of optical communication and optical information processing.

Description

Technical Field

[0001] This utility model relates to the field of integrated optical devices, specifically to a high-efficiency electro-optic modulator. Background Technology

[0002] With the rapid development of technologies such as 5G communication, data centers, and artificial intelligence, high-speed information transmission and processing have become key drivers of technological advancement. As communication technology continues to advance towards higher speeds and larger capacities, and with the rapid rise of optoelectronic technology, electro-optic modulators have emerged and quickly become core components in the fields of optical communication and optical information processing. In optical information processing, such as optical computing and optical storage, electro-optic modulators can flexibly control and process optical signals, enabling logical operations, data storage, and other functions, laying a solid foundation for building high-speed, efficient optical information processing systems. Electro-optic modulators play an irreplaceable and crucial role in the development of modern information technology.

[0003] With the increasing demands for high-speed, high-capacity information transmission, more functional devices need to be integrated within limited space. Due to limitations in modulation efficiency, electro-optic modulators often require a larger size to achieve the desired modulation effect. This larger size not only increases the space occupied by the device but also raises production costs, hindering large-scale integration and system miniaturization. Improving modulation efficiency can significantly reduce the size of electro-optic modulators, making them easier to integrate into high-density photonic chips. This not only reduces the overall system size and power consumption but also improves system stability and reliability. Therefore, improving the modulation efficiency of electro-optic modulators to reduce device size is an inevitable trend driving the development of optoelectronic technology to a higher level. Utility Model Content

[0004] To address the aforementioned technical problems, this invention provides a high-efficiency electro-optic modulator, comprising: a substrate material, an optical waveguide, a modulation electrode, an etched trench, and a cladding layer; wherein the optical waveguide is located on the substrate material; the modulation electrode is located on both sides of the optical waveguide, and the modulation electrode includes a signal electrode and a ground electrode; the etched trench is located between the optical waveguide and the modulation electrode; and the cladding layer covers the optical waveguide, the etched trench, and the modulation electrode.

[0005] Preferably, the materials used to fabricate the optical waveguide include lithium niobate, lithium tantalate, and barium titanate crystals.

[0006] Preferably, the material of the modulation electrode includes: Au, Ag, Cu, and Al.

[0007] Preferably, by optimizing the micro-nano fabrication process, etching trenches are simultaneously fabricated in the etching process of the optical waveguide. The etching process includes, but is not limited to, ICP, RIE, IBE, FIB, and wet etching.

[0008] Preferably, the cladding refractive index of the optical waveguide is less than the refractive index of the optical waveguide material.

[0009] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0010] This high-efficiency electro-optic modulator significantly improves modulation efficiency by incorporating etched trenches on both sides of the optical waveguide and employing specific waveguide and electrode materials. The presence of the etched trenches results in a more concentrated optical field distribution, effectively reducing transmission loss, while also allowing for smaller electrode spacing, enhancing the electric field strength, and thus improving the modulation effect. The etched trenches are formed simultaneously with the optical waveguide, simplifying the manufacturing process. Furthermore, this design reduces the device size, facilitating high-density integration of photonic chips and system miniaturization, providing a more efficient and compact solution for optical communication and optical information processing. Attached Figure Description

[0011] To more clearly illustrate the technical solution of this utility model, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the cross-sectional structure of a lithium niobate electro-optic modulator;

[0013] Figure 2 SEM images of the lithium niobate waveguide and etched trenches formed after the etching process were optimized.

[0014] Figure 3 The relationship between the transmission loss of the TEO mode and the electrode spacing in a lithium niobate optical waveguide with and without etched trenches is shown.

[0015] Explanation of reference numerals in the attached figures: 1. Optical waveguide; 2. Etched trench; 3. Modulation electrode; 4. Cladding. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 The diagram shown is a structural schematic of this embodiment. In this embodiment, the optical waveguide 1 is made of lithium niobate with a thickness of 600 nm; the cladding 4 is made of silicon dioxide. Alternatively, the optical waveguide 1 can also be made of lithium tantalate, barium titanate, or other crystals.

[0019] The electro-optic modulator provided in this embodiment is formed on an X-cut thin-film lithium niobate material. The optical waveguide 1 has a ridge waveguide structure, the etched trench 2 has a depth of 200 nm, and the waveguide width is 1.5 μm. The modulation electrode 3 is made of Au (other than Ag, Cu, Al, etc.) and is located on the planar layer of the lithium niobate waveguide, with the positive and negative electrodes located on opposite sides of the optical waveguide 1. Figure 2 As shown, the effect of etching trench 2 can be achieved by optimizing the parameters of the etching process. In this embodiment, the etching trench is simultaneously fabricated in the etching process of the optical waveguide by optimizing the micro-nano fabrication process. The etching process includes, but is not limited to, ICP, RIE, IBE, FIB, wet etching, etc.

[0020] In this embodiment, the etched trenches 2 formed on both sides of the optical waveguide 1 have a depth of 200nm and a width of 500nm; this embodiment will use these parameters as an example to illustrate the role of the etched trenches 2 in improving modulation efficiency.

[0021] like Figure 3As shown, the transmission loss of the TEO mode and the electrode spacing were calculated for the cases with and without etched trench 2. It can be seen that when the electrode spacing is close, the transmission loss of the TEO mode increases significantly due to the absorption of the light field by the metal. Therefore, the electrode spacing needs to be increased to reduce the transmission loss of the TEO mode. However, increasing the electrode spacing weakens the electric field strength in the optical waveguide 1, reducing the modulation effect. When trenches exist on both sides of the optical waveguide 1, the trenches are filled with silicon dioxide material, whose refractive index is much lower than that of lithium niobate, thus restricting the TEO mode and making the light field distribution more concentrated. Comparing the transmission loss of the TEO mode and the electrode spacing curves for the cases with and without etched trench 2, it can be found that when the transmission loss of the TEO mode is the same, the structure with etched trench 2 allows for a smaller electrode spacing. In this embodiment, the transmission loss of the TEO mode is taken as 0.5 dB / cm. At this time, the electrode spacings in the structures with and without etched trench 2 are 4.4 μm and 5.5 μm, respectively.

[0022] The optical and electric field distributions in the structures with and without etched trench 2 were then calculated. The results show that with etched trench 2, the TEO mode is well confined within the optical waveguide 1, with an effective mode area of ​​0.986. Without etched trench 2, the optical field extends outwards from the lithium niobate plate, resulting in an effective mode area of ​​1.13. The electric field distribution diagrams also show that, due to the closer electrode spacing, the electric field strength of the structure with etched trench 2 is significantly higher than that without. Further calculations show that the electric field of the lithium niobate electro-optic modulator with etched trench 2 is 1.795 Vcm, while that without etched trench 2 is 2.286 Vcm. This demonstrates that fabricating etched trench 2 improves the modulation efficiency of the lithium niobate electro-optic modulator by approximately 20%.

[0023] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Any modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A high-efficiency electro-optic modulator, characterized in that, include: The device comprises a substrate material, an optical waveguide, a modulation electrode, an etched trench, and a cladding layer; wherein the optical waveguide is located on the substrate material; the modulation electrode is located on both sides of the optical waveguide, and the modulation electrode includes a signal electrode and a ground electrode; the etched trench is located between the optical waveguide and the modulation electrode; and the cladding layer covers the optical waveguide, the etched trench, and the modulation electrode.

2. The high efficiency electro-optic modulator of claim 1, wherein, By optimizing micro-nano fabrication processes, etching trenches can be simultaneously fabricated during the etching process of optical waveguides. The etching processes include, but are not limited to, ICP, RIE, IBE, FIB, and wet etching.

3. The high efficiency electro-optic modulator of claim 1, wherein, The cladding refractive index of the optical waveguide is less than the refractive index of the optical waveguide material.

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