Electrooptical logic gate device of resonant ring-MIM waveguide based on surface plasmon

Abstract

The invention relates to the technical field of metal micro-nano optical devices, in particular to an electro-optical logic gate device of a resonant ring-MIM waveguide based on surface plasmons in the technical field of integrated circuit optical networks. The device structure comprises a resonant ring-MIM waveguide combined structure formed by a silicon dioxide slit, and an optical path coupling structure which is arranged in the MIM waveguide structure and controls optical signal coupling transmission through a voltage signal. According to the invention, the design operation and integration of the all-optical logic gate can be realized on the nanoscale by adopting a finite difference time domain (FDTD) method and utilizing the characteristic that the surface plasmon can break through the diffraction limit. And an AND gate, an OR gate and an exclusive-OR gate are realized, and rapid and efficient conversion of different logic functions is realized in the same structure. The method has great application prospects in the technical fields of optical signal processing, ultra-compact photonic integrated devices and sensing, helps the photonic integrated devices to be miniaturized and multifunctional, reduces energy consumption, and endows integrated optical regulation with flexible regulation and control information processing capability.

Description

Technical Field

[0001] The present invention relates to the technical field of metal micro-nano optical devices, and in particular to a device that uses the electro-optical effect to realize logic operation functions and a logic gate micro-nano device based on a resonant ring-MIM waveguide electro-optically controllable surface plasmon in the technical field related to optical signal processing. Background Art

[0002] Today, modern information technology is developing explosively, and people are increasingly eager for high-speed data transmission and processing capabilities. As the core cornerstone of optical signal processing technology, optical logic gates occupy a core position in many key fields such as optical switching systems, high-speed optical packet switching, all-optical address recognition, data coding, parity check, signal regeneration, optical computing, and future high-speed and large-capacity all-optical signal processing. Naturally, they have become the focus of current scientific research.

[0003] With the continuous advancement of science and technology, the miniaturization and high integration of optical devices have become the inevitable trend of industry development. However, traditional optoelectronic devices have encountered a huge obstacle in the development process, which is light diffraction. Electro-optical logic gates build a "bridge" between electrical signals and optical signals, combining the advantages of logic and modulation integration, simple structure, stable performance and signal optimization. In the context of the rapid development of information technology, optical logic gates, as the core unit of optical signal processing, are key components of optical switching systems and determinants of network performance, and play an important role in many fields. Once the size of the device is reduced to less than the wavelength of light, it is difficult for light to be effectively confined inside the device, resulting in many difficulties in the precise control of photons. In this difficult dilemma, the unique properties of surface plasmons were discovered. As an electron density wave at the metal-medium interface, surface plasmons have the excellent ability to tightly confine the light field within a tiny space of tens of nanometers, successfully breaking through the traditional diffraction limit, and have extremely powerful local field enhancement characteristics. Compared with traditional optoelectronic devices with a scale of several hundred nanometers, surface plasmons effectively break the shackles of the light diffraction limit on the development of optical integrated devices, paving a new path for nanoscale optical information transmission and processing, and have an irreplaceable key influence in the in-depth research and exploration of highly integrated photonic devices in the future. Based on this major breakthrough, the research on all-optical logic gates based on surface plasmons has flourished in recent years, mainly including optical logic gates based on surface plasmon polaritons (SPPs), optical logic gates based on localized surface plasmons (LSPs), and dynamically controllable all-optical logic gates. Unfortunately, most of these all-optical logic gates rely on the increase or decrease of the structure to achieve the switching between different logic gate functions. This implementation method is relatively complex and cumbersome, which is not conducive to the overall integrated design, and the universality performance is poor. High-frequency, high-speed, low-loss, miniaturized optoelectronic connectors, and make full use of the precious opportunities brought by the automation and intelligent upgrades in my country's industrial field, and strive to promote the widespread application of industrial-grade electronic components such as optical communication devices. Driven by this series of policies and guided by industry development trends, more and more researchers are focusing their attention and research interests on the research field of integrated circuits with optical devices as information carriers. This trend has not only greatly promoted the deep cross-penetration and integrated development among various disciplines and fields, but also injected strong impetus and vitality into the accelerated advancement of the information industrialization process. Summary of the invention

[0004] The purpose of the present invention is to provide an electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide, aiming to solve the existing technical problems of overcoming the heating and speed bottlenecks of traditional electronic integrated circuits, further improving the performance of optical logic gates in photonic integrated circuits, reducing signal transmission losses, and improving signal processing speed and accuracy.

[0005] To achieve the above-mentioned purpose, the present invention provides an electro-optical logic gate device based on a resonant ring-MIM waveguide of a surface plasmon, comprising: a substrate of Drude silver, a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit arranged on the substrate, and an optical path coupling structure arranged in the MIM waveguide structure for controlling the coupling transmission of optical signals through a voltage signal. Two input ports of two optical path signals on the input waveguide; an output waveguide for transmitting after the optical signal is coupled. The structure includes two input ends of optical path transmission and an output end of the optical path after the electrical coupling. By adopting the finite difference time domain method (FDTD) and utilizing the characteristics of surface plasmons that can break through the diffraction limit, the design, operation and integration of all-optical logic gates can be realized at the nanoscale. By controlling the transmission optical path of the light source and changing its different transmission coupling modes, the transmission of signals is realized. The transmission waveguide coupling mode is mainly changed by adjusting the voltage, and the transmission optical path can be regulated for the coupling structure to design different logic gate functions, including AND gate, OR gate, XOR gate, and fast and efficient conversion between different logic gate functions can be realized in the same structure.

[0006] Furthermore, the waveguide structure of the resonant ring-MIM waveguide is formed by slits deposited by etching the corresponding silicon dioxide material.

[0007] Furthermore, in the waveguide of the resonant ring-MIM waveguide structure, the slit widths of the resonant ring and the rectangular waveguide are equal in the horizontal plane.

[0008] Furthermore, the width of the resonant ring is 50 nm, and the width of the rectangular waveguide in the horizontal direction is 50 nm.

[0009] Furthermore, the average radius of the resonance ring in the horizontal direction is 230 nm, the maximum outer radius of the resonance ring is 255 nm, and the minimum inner radius is designed to be 205 nm.

[0010] Furthermore, the annular resonant ring and the output rectangular waveguide structure are placed horizontally, and the two structures are on the same horizontal symmetry axis to achieve effective and efficient transmission of optical signals.

[0011] Furthermore, the voltage signal-controlled optical coupling structure uses an organic electro-optical material, 4-(4-dimethylaminophenylvinyl)methylpyridine-p-toluenesulfonate (DAST).

[0012] Furthermore, the optical path coupling structure controlled by the voltage signal is symmetrically placed on both sides of the circular resonant ring.

[0013] Furthermore, the optical path coupling structure controlled by the voltage signal adds electrodes on both sides of the material, and the refractive index of the material changes linearly by applying an external voltage.

[0014] Furthermore, the light source signal input is a forward input of port1 and port2. When a single beam of light signal is input at the two ports respectively, its signal transmission is output through the output port, and the transmission efficiency is the same; then it is input at the same time through the two ports, and the signal transmission is coherently regulated by the waveguide structure, and the signal transmission rate is enhanced, realizing the "AND" gate logic operation of the structure.

[0015] When two light beams are input, the phase of the signal is changed so that the phase difference is a certain value. After the signal is coupled, the two light beams interfere with each other to realize the "OR" gate logic operation.

[0016] During the signal transmission process, the voltage control structure is used to change the optical path transmission, realize the phase cancellation mode between the two light beams, and significantly reduce the signal transmission rate at the output end, realizing the "XOR" gate logic operation of the structure.

[0017] The present invention provides an electro-optical logic gate device based on a resonant ring-MIM waveguide of a surface plasmon, comprising a substrate of Drude silver, a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit arranged on the substrate, and an optical path coupling structure arranged in the MIM waveguide structure to control the coupling transmission of an optical signal through a voltage signal. By adopting a finite difference time domain method (FDTD), the surface plasmon can break through the diffraction limit, and the design, operation and integration of an all-optical logic gate can be realized on a nanoscale. Compared with the prior art, its significant advantage is that: by means of the symmetrical structure of the all-optical logic gate, the logical functions of an AND gate, an OR gate, an XOR gate and an XOR gate are achieved. Moreover, only by selecting the port and changing the phase difference, the conversion of different logic functions can be realized under the same structure, which has good universality; the structure is relatively simple and easy to integrate, and other complex logic gates can be realized by cascading these three basic logic units. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0019] Figure 1 It is a structural schematic diagram of an electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide of the present invention.

[0020] Figure 2It is a schematic diagram of the signal transmission coupling structure of an electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide of the present invention.

[0021] Figure 3 The present invention is a schematic diagram of the effective medium refractive index and size of an electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide.

[0022] 1, 2-signal transmission input waveguide, 3-signal coupling output waveguide, 4-microring resonant structure, 5-electrically controlled coupling structure, 6-drude silver dielectric substrate. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] See also Figures 1 to 3 The present invention proposes an electro-optical logic gate device based on a resonant ring-MIM waveguide of a surface plasmon, including a substrate with Drude silver as the substrate, a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit arranged on the substrate, and an optical path coupling structure arranged in the MIM waveguide structure to control the coupling transmission of optical signals through voltage signals; by adopting the finite difference time domain method (FDTD), the surface plasmon can break through the diffraction limit, and the design, operation and integration of all-optical logic gates can be realized on a nanoscale. By controlling the transmission optical path of the light source and changing its different transmission coupling modes, signal transmission is realized. The transmission waveguide coupling mode is mainly changed by adjusting the voltage, and the transmission optical path of the coupling structure can be controlled to design different logic gate functions, including AND gate, OR gate, XOR gate, and fast and efficient conversion between different logic gate functions can be realized in the same structure.

[0025] More specifically, in one of the embodiments, the waveguide structure of the resonant ring-MIM waveguide is formed by slits deposited by etching of the corresponding silicon dioxide material.

[0026] More specifically, in one of the embodiments, the slit widths of the resonant ring and the rectangular waveguide in the waveguide of the resonant ring-MIM waveguide structure are equal in the horizontal plane.

[0027] More specifically, in one of the embodiments, the width of the resonant ring is 50 nm, and the width of the rectangular waveguide in the horizontal direction is 50 nm.

[0028] More specifically, in one of the embodiments, the average radius of the resonant ring in the horizontal direction is 230 nm, the maximum outer radius of the resonant ring is 255 nm, and the minimum inner radius is designed to be 205 nm.

[0029] More specifically, in one of the embodiments, the annular resonant ring and the output rectangular waveguide structure are placed horizontally, and the two structures are on the same horizontal symmetry axis to achieve effective and efficient transmission of optical signals.

[0030] More specifically, in one embodiment, two optical signal input rectangular MIM waveguides are symmetrically arranged about the resonant ring. The voltage signal controlled optical path coupling structure uses an organic electro-optical material 4-(4-dimethylaminophenylvinyl) methylpyridine p-toluenesulfonate (DAST).

[0031] More specifically, in one of the embodiments, the optical path coupling structure regulated by the voltage signal, the regulating structure is symmetrically placed on both sides of the circular resonant ring.

[0032] Specifically, in one embodiment, the optical path coupling structure controlled by the voltage signal adds electrodes on both sides of the material. By applying an external voltage, the refractive index of the material changes linearly.

[0033] More specifically, in one embodiment, the light source signal input is a forward input of port 1 and port 2. When a single beam of light signal is input at the two ports respectively, its signal transmission is output through the output port, and the transmission efficiency is the same; then, it is input at the same time through the two ports, and the signal transmission is coherently regulated by the waveguide structure, and the signal transmission rate is enhanced, realizing the "AND" gate logic operation of the structure.

[0034] When two light beams are input, the phase of the signal is changed so that the phase difference is a certain value. After the signal is coupled, the two light beams interfere with each other to realize the "OR" gate logic operation.

[0035] During the signal transmission process, the voltage control structure is used to change the optical path transmission, realize the phase cancellation mode between the two light beams, and significantly reduce the signal transmission rate at the output end, realizing the "XOR" gate logic operation of the structure.

[0036] The present invention also provides a specific embodiment and a simulation experiment for explanation:

[0037] As a specific example, the present invention is further described. Figure 1The electro-optical logic gate device based on the resonant ring-MIM waveguide of the surface plasmon includes a substrate of Drude silver, a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit arranged on the substrate, and an optical path coupling structure arranged in the MIM waveguide structure to control the coupling transmission of the optical signal through a voltage signal; the incident light source is a TM polarized plane wave, and the presence or absence of the two light sources to realize the four states of the signal (00), (01), (10), (11). When the optical signal is at 1550nm, the signal transmission rate realized by voltage regulation is 0, 0.31, 0.31, 0.003, and the corresponding output states are 0, 1, 1, 0, thereby realizing the "XOR" gate logic operation.

[0038] In the above manner, the voltage and the phase difference of the signal light source are changed, thereby changing the signal transmission optical path, generating different coupling modes, and resulting in a change in the signal transmission efficiency. The "AND" gate logic operation of the structure and the "OR" gate logic operation are realized.

[0039] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. An electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide, characterized in that: It includes a silver substrate for SPP excitation, a resonant ring-MIM waveguide structure for optical path transmission coupling arranged on the substrate, an optical path coupling structure regulated by a voltage signal, and two light source input ports arranged in the waveguide structure and an output port after signal coupling arranged at the other end of the structure. The nanocomposite structure, the resonant ring-MIM waveguide structure, the voltage regulation coupling structure and the metal silver substrate are placed at the same level. When the light source is coupled in the resonant ring, the voltage signal is changed to change the optical path transmission distance, and the coupled signal is then output through the waveguide 3. The transmission of different optical signals realizes the coupling of the structure because of the change in the optical path, so that the signal is transmitted through regulation, and the switching of the signal transmission of different optical logic gates is realized.

2. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claim 1, characterized in that: The waveguide structure of the resonant ring-MIM waveguide is formed by slits deposited by etching the corresponding silicon dioxide material.

3. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claim 2, characterized in that: In the waveguide of the resonant ring-MIM waveguide structure, the slit widths of the resonant ring and the rectangular waveguide are equal on the horizontal plane.

4. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device as claimed in claims 2 and 3, characterized in that: The width of the resonant ring is 50 nm, and the width of the rectangular waveguide in the horizontal direction is 50 nm.

5. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device as described in claims 2, 3, and 4, characterized in that: The average radius of the resonant ring in the horizontal direction is 230 nm, the maximum outer radius of the resonant ring is 255 nm, and the minimum inner radius is designed to be 205 nm.

6. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claims 1 to 5, characterized in that: The structures of the annular resonant ring and the output rectangular waveguide are placed horizontally, and the two structures are on the same horizontal symmetry axis to achieve effective and efficient transmission of optical signals.

7. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claims 1 to 6, characterized in that: Two optical signal input rectangular MIM waveguides are arranged symmetrically about the resonant ring.

8. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claim 1, characterized in that: The optical coupling structure controlled by voltage signal uses the organic electro-optical material 4-(4-dimethylaminophenylvinyl)methylpyridine p-toluenesulfonate (DAST).

9. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claim 8, characterized in that: The optical path coupling structure of voltage signal control is symmetrically placed on both sides of the circular resonant ring.

10. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device as claimed in claims 8 and 9, characterized in that: The optical coupling structure controlled by voltage signal adds electrodes on both sides of the material.

11. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to claims 1 to 10, characterized in that: The light source signal input is the forward input of port1 and port2. When a single beam of light signal is input at the two ports respectively, its signal transmission is output through the output port, and the transmission efficiency is the same; then it is input at the same time through the two ports, and the signal transmission is coherently regulated by the waveguide structure, and the signal transmission rate is enhanced, realizing the "AND" gate logic operation of the structure. When two light beams are input, the phase of the signal is changed so that the phase difference is a certain value. After the signal is coupled, the two light beams interfere with each other to realize the "OR" gate logic operation. During the signal transmission process, the voltage control structure is used to change the optical path transmission, realize the phase cancellation mode between the two light beams, and significantly reduce the signal transmission rate at the output end, realizing the "XOR" gate logic operation of the structure.

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