An optical logic gate device based on surface plasmon resonance ring-mim waveguide

Abstract

The application relates to the technical field of metal micro-nano optical devices, in particular to an electro-optical logic gate device based on a resonant ring-MIM waveguide of surface plasmons, belonging to the technical field of integrated circuit optical networks.The device structure comprises a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit, and an optical path coupling structure arranged in the MIM waveguide structure and used for controlling the coupling and transmission of optical signals through a voltage signal.The application can break through the diffraction limit by adopting the finite difference time domain (FDTD) method and using the characteristic that the surface plasmons can break through the diffraction limit, and can realize the design, operation and integration of all-optical logic gates on the nanometer scale.The application realizes AND gate, OR gate and XOR gate, and realizes the fast and efficient conversion of different logic functions in the same structure.The application has wide application prospects in the fields of optical signal processing, super-compact photonic integrated devices and sensing technology, helps the miniaturization and multifunctionalization of photonic integrated devices, reduces energy consumption, and gives integrated optical regulation the ability of flexible regulation and information processing.

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 logical operation functions and a surface plasmon-based resonant ring-MIM waveguide electro-optically controllable logic gate micro-nano device in the technical field related to optical signal processing. Background Art

[0002] With the explosive growth of modern information technology, people are increasingly eager for high-speed data transmission and processing capabilities. As the cornerstone of optical signal processing technology, optical logic gates play a central role in many key areas, including optical switching systems, high-speed optical packet switching, all-optical address recognition, data encoding, parity checking, signal regeneration, optical computing, and future high-speed, high-capacity all-optical signal processing. Naturally, they have become a hot topic in current scientific research.

[0003] With the continuous advancement of technology, the miniaturization and high integration of optical devices have become an inevitable trend in the industry. However, the development of traditional optoelectronic devices has encountered a significant obstacle: light diffraction. Electro-optical logic gates build a "bridge" between electrical and optical signals, combining the advantages of integrated logic and modulation, with a simple structure, stable performance, and signal optimization. Amid the rapid development of information technology, optical logic gates, as core units for optical signal processing, are key components in optical switching systems and determinants of network performance, playing a vital role in numerous fields. Once device dimensions shrink to below the wavelength of light, light becomes difficult to effectively confine within the device, making precise manipulation of photons challenging. Faced with this difficult dilemma, the unique properties of surface plasmons have been discovered. Surface plasmons, electron density waves at metal-dielectric interfaces, possess the remarkable ability to tightly confine light fields to a tiny volume of tens of nanometers, successfully breaking through the traditional diffraction limit and possessing extremely powerful local field enhancement properties. Compared to traditional optoelectronic devices operating at scales of a few hundred nanometers, surface plasmons have effectively overcome the constraints imposed by the diffraction limit on the development of optical integrated devices, paving a new path for nanoscale optical information transmission and processing. They hold irreplaceable and crucial influence on the future research and exploration of highly integrated photonic devices. Building on this significant breakthrough, research on surface plasmon-based all-optical logic gates has flourished in recent years, primarily encompassing optical logic gates based on surface plasmon polaritons (SPPs), localized surface plasmons (LSPs), and dynamically controllable all-optical logic gates. Unfortunately, most of these all-optical logic gates rely on structural modifications to switch between different logic gate functions. This implementation is complex and cumbersome, hindering overall integrated design and lacking universal applicability. High-frequency, high-speed, low-loss, and miniaturized optoelectronic connectors are being developed to fully leverage the valuable opportunities presented by the automation and intelligent upgrades in my country's industrial sector, promoting 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 field of integrated circuit research using optical devices as information carriers. This trend has not only greatly promoted the deep cross-penetration and integrated development between various disciplines and fields, but also injected strong momentum 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 loss, and improving signal processing speed and accuracy.

[0005] To achieve the above objectives, the present invention provides an electro-optical logic gate device based on a surface plasmon resonant ring-MIM waveguide. The device comprises: a Drude silver substrate, a resonant ring-MIM waveguide structure formed of a silicon dioxide slit disposed on the substrate, and an optical coupling structure within the MIM waveguide structure that controls the coupling and transmission of optical signals via voltage signals. The input waveguides contain two input ports for two optical signals; and an output waveguide for transmitting the coupled optical signals. The structure includes two optical transmission inputs and an electrically coupled optical output. By employing the finite-difference time-domain (FDTD) method and leveraging the diffraction-limited properties of surface plasmons, the design, operation, and integration of all-optical logic gates can be realized at the nanoscale. Signal transmission is achieved by controlling the optical path length of the light source and changing its transmission coupling mode. By adjusting the voltage to change the transmission waveguide coupling mode, the coupling structure can be manipulated to control the optical path length, thereby designing different logic gate functions, including AND, OR, and XOR gates. Fast and efficient conversion between different logic gate functions can also be achieved within 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 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.

[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 voltage signal controlled optical coupling structure adds electrodes on both sides of the material, and causes a linear change in the refractive index of the material by applying an external voltage.

[0014] Furthermore, the light source signal input is a forward input at port 1 and port 2. When a single light beam is input at each of the two ports, the signal is transmitted through the output port with the same transmission efficiency. Then, when the signal is input simultaneously at both ports, the signal transmission is coherently controlled by the waveguide structure, enhancing the signal transmission rate and 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 signals are coupled, the two light beams interfere with each other, realizing the "OR" gate logic operation.

[0016] During the signal transmission process, the voltage control structure is used to change the optical path transmission to achieve a phase cancellation mode between the two light signals. The signal transmission rate at the output end is significantly reduced, realizing the "exclusive OR" gate logic operation of the structure.

[0017] The present invention provides an electro-optical logic gate device based on a surface plasmon resonator ring-MIM waveguide. The device comprises a Drude silver substrate, a resonator ring-MIM waveguide structure formed by a silicon dioxide slit disposed on the substrate, and an optical path coupling structure within the MIM waveguide structure that controls the transmission of optical signals through voltage signals. By employing the finite-difference time-domain (FDTD) method and leveraging the diffraction-limited properties of surface plasmons, the device enables the design, operation, and integration of all-optical logic gates at the nanoscale. Compared to existing technologies, the device offers significant advantages: leveraging the symmetric structure of all-optical logic gates, it achieves the logical functions of AND, OR, XOR, and XOR gates. Furthermore, by simply selecting ports and varying the phase difference, different logical functions can be converted within the same structure, demonstrating excellent universality. The device is relatively simple and easy to integrate, and other complex logic gates can be implemented 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[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 This 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 of the present invention.

[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 objectives, technical solutions and advantages of the present application more clearly understood, embodiments of the present invention are described in detail below. 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 having 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 surface plasmon resonant ring-MIM waveguide. The device comprises a Drude silver substrate, a resonant ring-MIM waveguide combination structure formed by a silicon dioxide slit disposed on the substrate, and an optical path coupling structure disposed within the MIM waveguide structure that controls the coupling and transmission of optical signals via voltage signals. By employing the finite-difference time-domain method (FDTD) and utilizing the surface plasmon's ability to break through the diffraction limit, the design, operation, and integration of all-optical logic gates can be realized at the nanoscale. Signal transmission is achieved by controlling the optical path of the light source and changing its different transmission coupling modes. The coupling mode of the transmission waveguide 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 gates, OR gates, and XOR gates. Fast and efficient conversion between different logic gate functions can also be achieved within the same structure.

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

[0026] More specifically, in one embodiment, 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 embodiment, 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 embodiment, 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 embodiment, 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-controlled optical coupling structure uses the organic electro-optical material 4-(4-dimethylaminostyryl)methylpyridinium p-toluenesulfonate (DAST).

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

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

[0033] More specifically, in one embodiment, the light source signal input is forward input at port 1 and port 2. When a single light beam is input at each port, the signal is transmitted through the output port with the same transmission efficiency. Then, when the signal is input simultaneously at both ports, the signal transmission is coherently controlled by the waveguide structure, enhancing the signal transmission efficiency and implementing 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 signals are coupled, the two light beams interfere with each other, realizing the "OR" gate logic operation.

[0035] During the signal transmission process, the voltage control structure is used to change the optical path transmission to achieve a phase cancellation mode between the two light signals. The signal transmission rate at the output end is significantly reduced, realizing the "exclusive OR" gate logic operation of the structure.

[0036] The present invention also provides a specific embodiment and simulation experiments for illustration:

[0037] As a specific example, the present invention is further described. Figure 1The electro-optical logic gate device based on the surface plasmon resonant ring-MIM waveguide includes a substrate made 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 optical signals through voltage signals; the incident light source is a TM polarized plane wave, and the presence or absence of two light beams can realize the four states of the signal (00), (01), (10), and (11). When the optical signal is at 1550nm, the signal transmission rate achieved by voltage regulation is 0, 0.31, 0.31, and 0.003, and the corresponding output states are 0, 1, 1, and 0, thereby realizing the "exclusive OR" gate logic operation.

[0038] In this way, by changing the voltage and the phase difference of the signal light source, the signal transmission optical path is changed, resulting in different coupling modes and a change in signal transmission efficiency. This structure implements both the "AND" gate logic operation and the "OR" gate logic operation.

[0039] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the 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 in accordance with the claims of the present invention are still 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: The invention comprises a silver substrate for SPP excitation, a resonant ring-MIM waveguide structure for optical transmission coupling arranged on the silver substrate, an optical coupling structure regulated by a voltage signal, two light source input ports arranged in the waveguide structure, and an output port for signal coupling arranged at the other end of the structure; the resonant ring-MIM waveguide structure, the optical coupling structure, and the silver substrate are placed at the same horizontal height, and the light is transmitted by changing the voltage signal during the coupling transmission of the resonant ring, and the coupled signal is output through the signal coupling output end waveguide; the transmission of different optical signals realizes structural coupling due to the change of the optical path, so that the signal is transmitted through regulation and switching of different optical logic gate signal transmissions; the two optical signal input rectangular MIM waveguides are symmetrically arranged about the resonant ring; the optical coupling structure regulated by the voltage signal uses the organic electro-optical material 4-(4-dimethylaminostyryl)methylpyridine toluenesulfonate (DAST); the optical coupling structure regulated by the voltage signal is symmetrically placed on both sides of the circular resonant ring; the optical coupling structure regulated by the voltage signal has electrodes added on both sides of the material; The two optical path coupling structures are respectively located on one side of the two optical signal input rectangular MIM waveguide resonant rings.

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 depositing and etching 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 widths of the resonant ring and the rectangular waveguide are equal in the horizontal plane.

4. The surface plasmon resonant ring-MIM waveguide electro-optical logic gate device according to 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 according to 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 annular resonant ring and the signal coupling output 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: The light source signal input is the 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 with the same transmission efficiency. Then, when it is input simultaneously at the two ports, 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, realizing the "OR" gate logic operation. During signal transmission, the voltage-controlled structure is used to change the optical path transmission, realizing a phase cancellation mode between the two optical signals. The signal transmission rate at the output end is significantly reduced, realizing the "exclusive OR" gate logic operation of the structure.

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