Dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect

Abstract

This invention proposes a dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect. It includes a photonic crystal waveguide with a TE bandgap, disposed on a photonic crystal. Several silicon dielectric pillars are arranged on the photonic crystal, with the waveguide positioned between them. The input waveguide has an input port, and the output waveguide has two output ports with opposite directions. A resonant cavity is located between the input port and the two output ports. A defective dielectric pillar is located within the resonant cavity, with electrodes coated with electrochemical metal at both ends. These electrodes are connected to a bias circuit. Due to the resistive switching effect, when a voltage is applied across the defective dielectric pillar, conductive filaments are formed inside, thereby adjusting the resonant frequency of the resonant cavity and controlling the switching of the signal light. This invention is easy to array, has a small structure size, fast switching time response, high optical transmission efficiency, and is non-volatile.

Description

Technical Field

[0001] This invention relates to the technical field of electrically controlled photonic crystal optical switches, and more particularly to a dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect. Background Technology

[0002] In recent years, with the rapid development of optical information technology, various new optoelectronic devices have played an important role in social production. Among them, optical switches, as important basic devices, play a crucial role and are also a cutting-edge issue in optical communication technology research. At present, the most commonly used technical means to realize optical switches include microelectromechanical systems (MEMS) optical switches, optical switches based on nonlinear effects (electro-optic, acousto-optic, thermo-optic, and magneto-optic, etc.), silicon-based optical waveguide switches, etc. However, these optical switch technologies usually have their own insurmountable problems: (1) Optical switches based on MEMS technology have disadvantages such as large structural size, slow switching speed (millisecond level), large system size, and poor stability. (2) Optical switches based on nonlinear effects generally have large volume and power consumption. The nonlinear coefficient of the material of optical switch devices using nonlinear effects is limited. In order to achieve a 180° phase change, a strong laser intensity and a large volume of nonlinear material are required, which poses a challenge to the miniaturization and low power consumption of optical switch devices. (3) Silicon-based optical waveguide switch technology still faces the problems of high power consumption and large size. On the one hand, the principle of this optical switch technology utilizes optical nonlinear effects to cause interference or resonance within the waveguide, thereby realizing the switching of optical signals. On the other hand, silicon-based optical switches using phase change materials require the phase change material to be heated and melted to undergo a phase change, which inevitably increases energy consumption. (4) Most existing optical switches are volatile. After power is turned off, most existing optical switches cannot maintain their switching state. In addition, this is another important reason for the high power consumption of optical switch devices. Therefore, abandoning nonlinear effects and developing optical switches with non-volatile characteristics has become the key to solving the problems of high power consumption and large size of existing optical switches.

[0003] Miniature devices based on photonic crystals, such as photonic crystal optical switches, are constructed by introducing point defects into photonic crystal waveguides. Furthermore, multi-channel optical switches offer higher integration density than single-channel switches, so exploring and developing multi-channel optical switches can further improve device integration. Due to the resistive switching effect, applying a voltage across the points-defect dielectric pillars can create nanoscale metal filaments within them, thereby altering the position of the point defects and ultimately changing the transmittance of the photonic crystal waveguide. This constitutes a photonic crystal optical switch based on the resistive switching effect structure. Additionally, the conductive metal filaments formed by the resistive switching effect exhibit excellent stability, remaining stable even after the external voltage is removed. Therefore, optical switches based on this principle are non-volatile. Summary of the Invention

[0004] To address the technical challenges of large structural size and difficult integration of existing optical switches, this invention proposes a dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect. This switch can be combined to achieve the function of an array-based optical switch. Furthermore, this invention features a small structural size, fast switching time response, high optical transmission efficiency, a wider bandgap, and a broader operating bandwidth, making it suitable for large-scale optical path integration. Its non-volatility also gives it significant practical value.

[0005] To achieve the above objectives, the technical solution of this invention is as follows: A dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect, comprising a photonic crystal waveguide with a TE bandgap, the photonic crystal waveguide being disposed on a photonic crystal, a plurality of silicon dielectric pillars being disposed on the photonic crystal, and the photonic crystal waveguide being disposed between the silicon dielectric pillars; the input port of the photonic crystal waveguide is provided with an input terminal, and the output port of the photonic crystal waveguide is provided with an output terminal I and an output terminal II, the angle between the input terminal and output terminal I, and the angle between the input terminal and output terminal II being greater than 90°, and the angle between output terminal I and output terminal II being greater than 90°. The directions of I are opposite; a resonant cavity I is provided between the input terminal and the output terminal I, and a defective dielectric pillar I is provided inside the resonant cavity I; a resonant cavity II is provided between the input terminal and the output terminal II, and a defective dielectric pillar II is provided inside the resonant cavity I; both ends of the defective dielectric pillar I and the defective dielectric pillar II are provided with electrochemical metal electrodes, and both ends of the electrodes are connected to a bias circuit that provides a bias voltage; due to the resistive switching effect, when a voltage is applied to both ends of the defective dielectric pillar, a conductive filament will be formed inside the defective dielectric pillar, thereby adjusting the resonant frequency of the resonant cavity, and finally achieving the function of controlling the opening and closing of the signal light.

[0006] Preferably, the bias circuit includes a square wave signal generator, which is connected to the electrodes at both ends of the defective dielectric pillar I via wires, and the square wave signal generator is connected to the electrodes at both ends of the defective dielectric pillar II via wires.

[0007] Preferably, the silicon dielectric pillar is circular in shape.

[0008] Preferably, the photonic crystal is a two-dimensional hexagonal lattice photonic crystal, the angle between the input end and the output end I and the output end II is 120°, and the space enclosed by the six silicon dielectric pillars arranged at the hexagonal angles forms resonant cavity I or resonant cavity II.

[0009] Preferably, the defective dielectric pillar I is located at the center of resonant cavity I, and the defective dielectric pillar II is located at the center of resonant cavity II; the center of the defective dielectric pillar I or the defective dielectric pillar II is set on the straight line where the output photonic crystal waveguide is located.

[0010] Preferably, the waveguide plane of the photonic crystal waveguide is perpendicular to the axis of the silicon dielectric pillar in the photonic crystal, and the optical axis of defective dielectric pillar I or defective dielectric pillar II is in the same direction as the silicon dielectric pillar.

[0011] Preferably, the photonic crystal dielectric pillar and the background are composed of a high refractive index material and a low refractive index material, respectively; the high refractive index material is silicon or a medium with a refractive index greater than 3; the low refractive index material is air or a medium with a refractive index less than 1.4; the defect dielectric pillar I and defect dielectric pillar II are made of oxide materials with a refractive index less than 2 and which are easy to form conductive filaments; the electrode is made of a material that is easy to undergo resistive switching effect.

[0012] Preferably, the defect dielectric column I is made of silicon dioxide, and the defect dielectric column II is made of titanium dioxide; the electrode is a silver electrode or a copper electrode.

[0013] Preferably, the photonic crystal waveguide receives TE light from the input terminal, and the square wave signal generator of the bias circuit outputs square wave signals with different polarities. The square wave signals control the optical signal to couple into output terminal I through resonant cavity I and into output terminal II through resonant cavity II. The two ends of the defect dielectric pillar are plated with electrochemical metal. When the square wave signal generator generates a square wave pulse that acts on the two ends of the electrode, conductive filaments will form in the defect dielectric pillar. The formation or breakage of the conductive filaments changes the resonant frequency of the resonant cavity, thereby changing the output power of the output terminal and changing the state of the optical switch.

[0014] Preferably, the radius of the silicon dielectric pillar is R=0.3a, the radius of the defect dielectric pillar is r=0.2a, and the waveguide width is d1=1.132a, where a is the lattice constant of the photonic crystal; the TE bandgap parameters in the photonic crystal are calculated using the plane wave expansion method, where the frequency ranges of the two TE bandgap are 0.414 to 0.531 (ωa / 2πc) and 0.631 to 0.744 (ωa / 2πc), respectively, where ω and c represent the angular frequency and the speed of light in free space, respectively.

[0015] The operating wavelength ranges of the TE bandgap are 1.88a to 2.41a and 1.34a to 1.58a, respectively. The operating wavelength is adjusted by changing the lattice constant, the material and size of defect dielectric pillar I or defect dielectric pillar II. The extinction ratio of the optical switch is 10log (output power of the output port when on / output power of the output port when off).

[0016] Compared with existing technologies, the advantages of this invention are: It facilitates arraying; based on the dual-channel design, the function of arrayed optical switches can be achieved through combination; it has a small structural size, fast switching time response, and high optical transmission efficiency, making it suitable for large-scale optical path integration; it has a wider bandgap and a wider operating bandwidth; since hexagonal lattice photonic crystals have a wider bandgap than square lattice photonic crystals, the proportional scaling characteristic of photonic crystals can be applied by proportionally changing the lattice constant to achieve optical path switching functions of different wavelengths within a larger bandwidth; it has a high extinction ratio and adjustable operating wavelength, allowing pulses with a certain spectral width, or Gaussian light, or light of different wavelengths to work, or light of multiple wavelengths to work simultaneously, which has great practical significance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the planar structure of the present invention.

[0019] Figure 2 This is a perspective view of the present invention.

[0020] Figure 3 This is a diagram showing the distribution of structural parameters of the present invention.

[0021] Figure 4 This is a waveform diagram of the switch in this invention.

[0022] Figure 5 The transmission characteristics in the switch state in Embodiment 1 of the present invention are shown, where (a) is the output characteristic curve of output terminal I and (b) is the output characteristic curve of output terminal II.

[0023] Figure 6 This is a schematic diagram of the light field distribution of the switch when the output terminal I is used as a switch channel in Embodiment 1 of the present invention. (a) is the light field distribution when the output terminal I is turned on, and (b) is the light field distribution when the output terminal I is turned off.

[0024] Figure 7This is a schematic diagram of the light field distribution of the switch when the output terminal II is used as a switch channel in Embodiment 1 of the present invention. (a) is the light field distribution when the output terminal II is turned on, and (b) is the light field distribution when the output terminal II is turned off.

[0025] Figure 8 The transmission characteristics in the switching state in Embodiment 2 of the present invention are shown, where (a) is the output characteristic curve of output terminal I and (b) is the output characteristic curve of output terminal II.

[0026] Figure 9 This is a schematic diagram of the light field distribution of the switch when the output terminal I is used as a switch channel in Embodiment 2 of the present invention. (a) is the light field distribution when the output terminal I is turned on, and (b) is the light field distribution when the output terminal I is turned off.

[0027] Figure 10 This is a schematic diagram of the light field distribution of the switch when the output terminal II is used as a switch channel in Embodiment 2 of the present invention. (a) is the light field distribution when the output terminal II is turned on, and (b) is the light field distribution when the output terminal II is turned off.

[0028] In the figure, 1 is the input terminal, 2 is the output terminal I, 3 is the silicon dielectric pillar, 4 is the resonant cavity I, 5 is the defective dielectric pillar I, 6 is the output terminal II, 7 is the resonant cavity II, 8 is the defective dielectric pillar II, 9 is the wire, and 10 is the square wave signal generator. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1The diagram shows a schematic of a dual-channel photonic crystal non-volatile optical switch based on resistive switching effect (excluding the external control circuit, i.e., bias circuit). It includes a photonic crystal waveguide with a TE bandgap. The photonic crystal optical switch also includes an input terminal 1, two output terminals (output terminal I2 and output terminal II6), a silicon dielectric pillar 3 as the background, two resonant cavities (resonant cavity I4 and resonant cavity II7), and two defect dielectric pillars I5 and II8 with silver electrodes plated at both ends. The angle between the input terminal 1 and the output terminals I2 and II6 is 120°, and the directions of the output terminals I2 and II6 are opposite. The two resonant cavities are located between the input terminal 1 and the output terminals I2 and II6, respectively. The photonic crystal carrier input terminal is located at the right end of the device, and the output ports are located above and below the device. The initial signal light of this device is incident from the right input terminal 1, and light waves of different wavelengths are output from the output terminals I2 and II6, respectively. The photonic crystal waveguide receives TE light at input terminal 1. A square wave signal generator 10 outputs square wave signals of different polarities. These square wave signals control the optical signal, which couples through resonant cavity I 4 to output terminal I 2 and through resonant cavity II 7 to output terminal II 6. Defective dielectric pillar I 5 is located at the center of resonant cavity 4, and defective dielectric pillar II 8 is located at the center of resonant cavity II 7. Both ends of defective dielectric pillars I 5 and II 8 are plated with silver electrodes and connected to the square wave signal generator 10 via wire 9.

[0031] like Figure 2 As shown, another structural schematic diagram of the present invention (including an external control circuit) is presented. The bias circuit providing the bias voltage includes two identical square wave signal generators 10 and wires 9. The two ends of the first square wave signal generator 10 are respectively connected to the two silver electrodes of the defective dielectric pillar I 5 via wires 9; the two ends of the second square wave signal generator 10 are respectively connected to the two silver electrodes of the defective dielectric pillar II 8 via wires 9. Figure 1 and Figure 3 The structural diagram shown uses a Cartesian coordinate system; the positive X-axis is horizontal to the right, the positive Y-axis is vertically upward in the plane of the paper, and the positive Z-axis is perpendicular to the plane of the paper and outward.

[0032] The silicon dielectric pillar 3 and the background of the photonic crystal are composed of a high-refractive-index material and a low-refractive-index material, respectively; the high-refractive-index material is silicon or a medium with a refractive index greater than 3; the low-refractive-index material is air or a medium with a refractive index less than 1.4. This choice is advantageous for forming a wide TE bandgap. The silicon dielectric pillar 3 is circular in shape.

[0033] like Figure 3As shown, the relevant parameters of this device are: 'a' is the lattice constant of the photonic crystal, the radius R of the silicon dielectric pillar 3 is 0.3a, the radius r of the defect dielectric pillar is 0.2a, and the waveguide width d1 is 1.132a. The photonic crystal of this invention is a two-dimensional hexagonal lattice photonic crystal with a lattice constant of 'a' and a dielectric pillar radius of 0.3a. The TE bandgap parameters in the photonic crystal are calculated using the plane wave expansion method. The frequency ranges of the two TE bandgap bands are 0.414 to 0.531 (ωa / 2πc) and 0.631 to 0.744 (ωa / 2πc), respectively. Light waves of any frequency within these ranges will be confined in the waveguide.

[0034] The photonic crystal waveguide used in this invention is formed by removing a portion of the silicon dielectric pillar. The photonic crystal waveguide is the structure of a photonic crystal after removing a portion of the dielectric pillar. The waveguide plane is perpendicular to the axis of the dielectric pillar in the photonic crystal. Defective dielectric pillar I 5 is located at the center of resonant cavity I 4. Defective dielectric pillar II 8 is located at the center of resonant cavity II 7. The resonant cavity is formed by removing the central background silicon dielectric pillar and replacing it with a defective dielectric pillar; that is, the center of the defective dielectric pillar is on the same straight line as the center of the silicon dielectric pillar. The optical axis of the defective dielectric pillar is aligned with the direction of the background silicon dielectric pillar. The waveguide at input terminal 1 is the input photonic crystal waveguide, and the waveguides at output terminals I 2 and II 6 are the output photonic crystal waveguides.

[0035] The defect dielectric pillar I 5 is made of an oxide material with a refractive index below 2, such as silicon dioxide, which readily forms conductive filaments. The defect dielectric pillar II 8 is made of an oxide material with a refractive index above 2, such as titanium dioxide, which readily forms conductive filaments. This allows the two resonant cavities to have different resonant frequencies. The electrodes plated at both ends of the defect dielectric pillars I 5 and II 8 are made of materials such as silver and copper, which readily undergo electrochemical oxidation-reduction reactions.

[0036] The principle of this invention mainly explains the formation and collapse of conductive filaments and their impact on optical transmission characteristics. The formation and collapse of conductive filaments is a phenomenon observed in resistive switching memories (RSMs), also known as the resistive switching effect. Under the influence of an external electric field, the active electrodes of an RSM undergo an electrochemical oxidation-reduction reaction within the RSM's dielectric, ultimately forming metallic conductive filaments connecting the electrodes within the dielectric. Theory and experiments have confirmed that the formation and collapse of these conductive filaments can occur in as little as the picosecond (ps) timescale. In this invention, the two ends of the defective dielectric pillar are plated with metallic silver. When a square wave pulse generated by a square wave signal generator is applied to the two ends of the silver electrodes, silver conductive filaments form within the defective dielectric pillar. The formation of these conductive filaments alters the resonant frequency of the resonant cavity, thereby changing the output power at the output terminal and thus altering the state of the optical switch.

[0037] The optical switch of this invention is generally implemented through the following method: Initially, no conductive filaments are formed within the defective dielectric pillar. When light of different wavelengths enters the device through the input waveguide, light with the same resonant frequency as the two resonant cavities will couple into the resonant cavities and be simultaneously output from the corresponding output terminals. The output waveguide has relatively high optical power, and the switch is in the on state at this time. When one of the square wave signal generators generates a positive square wave signal and applies it to both ends of the defective dielectric pillar, silver undergoes an electrochemical oxidation-reduction reaction under the influence of an electric field, forming a conductive filament connecting the electrodes at both ends within the defective dielectric pillar. At this time, the resonant frequency of the resonant cavity changes, and the original wavelength can no longer couple into the resonant cavity. Therefore, the output optical power of the corresponding channel's output waveguide is very low, and the switch for that channel is in the off state at this time. Since the conductive filaments are relatively stable after formation, the switch will remain in the off state even without an external electric field, thus giving the optical switch the characteristic of non-volatility. When the square wave signal generator produces a negative square wave signal and applies it to both ends of the defective dielectric pillar, due to the same factors, the conductive filaments that have already formed inside the defective dielectric pillar will break off from the dielectric and gradually disappear. This causes the resonant frequency of the resonant cavity to return to its original frequency. The previously blocked light wave can then be output normally from the output port through the resonant cavity, thus putting the switch back on.

[0038] The lattice constant and operating wavelength can be determined using the following method: through the formula...

[0039] (1)

[0040] Among them, λ, , These represent wavelength, normalized wavelength, and normalized frequency, respectively.

[0041] In this invention, a normalized TE bandgap frequency is used in a photonic crystal with a hexagonal lattice silicon structure. f norm The ranges are 0.414 to 0.531 and 0.631 to 0.744, respectively. The corresponding TE bandgap wavelength ranges are calculated to be λ = 1.88a to 2.41a and 1.34a to 1.58a. Furthermore, the output wavelength is related to the resonant wavelength of the resonant cavity, which can be changed by adjusting the material and size of the defect dielectric pillar. Therefore, it can be seen that, without considering dispersion or with very small changes in material dispersion, a wavelength value that satisfies the wavelength range proportionally can be obtained by changing the lattice constant α, the material, and the thickness of defect dielectric pillar I or defect dielectric pillar II. The operating wavelength can be adjusted by changing the lattice constant, the material, and the size of defect dielectric pillar I or defect dielectric pillar II.

[0042] like Figure 4As shown, by controlling the square wave signal generator to output square wave signals of different polarities, the output waveform of optical power is obtained. Here, τ1 and τ2 are the switching transition times, which are also the pulse widths of the square wave signals. Since the formation and rupture of the conductive filaments are very rapid, on the order of ps, while the pulse width of the square wave signal is on the order of nanoseconds, the pulse width time can be considered to be the switching transition time.

[0043] The parameters of the optical switch: The switching contrast ratio (extinction ratio) is defined as 10log(output power of the output port when on / output power of the output port when off) = 10log(P 开 / P 关 ).like Figure 5 The figure shows the output power of the optical switch when it is in the on and off states. Figure 5 It can be seen that at normalized optical frequencies ωa / 2πc = 0.4545 and 0.685, the output channels I2 and II6 have maximum output power in the on state and relatively low output power in the off state. According to the extinction ratio formula, at this normalized wavelength, the extinction ratio of output channel I2 can reach 49.8 dB, and the extinction ratio of output channel II6 can reach 14.9 dB.

[0044] Implementation Case 1

[0045] A dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect is presented in this embodiment. Under the condition of negligible dispersion or minimal material dispersion variation, optical switching functions for different wavelengths can be achieved by proportionally changing the lattice constant. Other parameters are set as follows: a = 0.4 μm, R = 0.3 a, r = 0.2 a, d1 = 1.132 a, and the normalized optical frequencies ωa / 2πc are 0.4545 and 0.685, respectively. With other parameters unchanged, the output channel I2 corresponds to an 880 nm light wave, and the output channel II6 corresponds to a 584 nm light wave. Simulation calculations yield the output power of the output channel I2 in the on and off states corresponding to light waves in the range of the normalized frequency 0.4545. Figure 5 As shown in (a). The output power of the output terminal II 6 channel, corresponding to the light wave in the range of near the normalized frequency of 0.685, in both the on and off states is calculated as follows. Figure 5 As shown in (b), the switching extinction ratio of output channel I2 can be calculated to be 49.8dB, and the switching extinction ratio of output channel II6 can be 14.9dB. Figure 6 and Figure 7 The figures show the electric field distribution of the output I 2-channel and the output II 6-channel switches in the on and off states, respectively. It can be seen from the figures that most of the energy passes through the device when the switch is on, and there is basically no crosstalk between the two channels when the switch is off.

[0046] Implementation Case 2

[0047] A dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect is presented in this embodiment. Under the condition of negligible dispersion or minimal material dispersion variation, optical switching functions at different wavelengths can be achieved by proportionally changing the lattice constant. Other parameters are set as follows: a = 0.45 μm, R = 0.3a, r = 0.2a, d1 = 1.132a, and the normalized optical frequency ωa / 2πc is 0.4540 and 0.683, respectively. Other parameters remain unchanged, so that the output channel I2 corresponds to a light wave of 991 nm, and the output channel II6 corresponds to 659 nm. Simulation calculations yield the output power of the output channel I2 in the on and off states corresponding to light waves in the range of the normalized frequency near 0.4540. Figure 8 As shown in (a). The output power of the output terminal II 6 channel, corresponding to the light wave in the range of near the normalized frequency of 0.683, in both the on and off states is calculated as follows. Figure 8 As shown in (b), the switching extinction ratio of the output I2 channel can reach 50.7dB, and the switching extinction ratio of the 6-channel can reach 14.5dB. Figure 9 and Figure 10 The figures show the electric field distribution of the output I2 channel and the output II6 channel in the on and off states, respectively. It can be seen from the figures that most of the energy passes through the device when the switch is on, and there is basically no crosstalk between the two channels when the switch is off.

[0048] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect, characterized in that, The device includes a photonic crystal waveguide with a TE bandgap, which is disposed on a photonic crystal. Several silicon dielectric pillars (3) are disposed on the photonic crystal, and the photonic crystal waveguide is positioned between the silicon dielectric pillars (3). The input port of the photonic crystal waveguide has an input terminal (1), and the output port of the photonic crystal waveguide has an output terminal I (2) and an output terminal II (6). The angle between the input terminal (1) and the output terminal I (2), and between the input terminal (1) and the output terminal II (6), is greater than 90°. The directions of the output terminals I (2) and II (6) are opposite. A harmonic current is provided between the input terminal (1) and the output terminal I (2). A resonant cavity I (4) is provided with a defective dielectric pillar I (5); a resonant cavity II (7) is provided between the input end (1) and the output end II (6), and a defective dielectric pillar II (8) is provided inside the resonant cavity II (7); both ends of the defective dielectric pillar I (5) and the defective dielectric pillar II (8) are provided with electrochemical metal electrodes, and both ends of the electrodes are connected to a bias circuit that provides bias voltage; due to the resistive switching effect, when a voltage is applied to both ends of the defective dielectric pillar, a conductive filament will be formed inside the defective dielectric pillar, thereby adjusting the resonant frequency of the resonant cavity, and finally achieving the function of controlling the opening and closing of the signal light.

2. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 1, characterized in that, The bias circuit includes a square wave signal generator (10), which is connected to the electrodes at both ends of the defective dielectric column I (5) via wires (9) and to the electrodes at both ends of the defective dielectric column II (8) via wires (9).

3. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 1 or 2, characterized in that, The silicon dielectric pillar (3) is circular in shape.

4. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 3, characterized in that, The photonic crystal is a two-dimensional hexagonal lattice photonic crystal. The angle between the input end (1) and the output end I (2) and the output end II (6) is 120°. The space enclosed by the six silicon dielectric pillars (3) set at the hexagonal angle forms the resonant cavity I (4) or the resonant cavity II (7).

5. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 4, characterized in that, The defective dielectric pillar I (5) is located at the center of resonant cavity I (4), and the defective dielectric pillar II (8) is located at the center of resonant cavity II (7); the center of the defective dielectric pillar I (5) or the defective dielectric pillar II (8) is set on the straight line where the output photonic crystal waveguide is located.

6. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 5, characterized in that, The waveguide plane of the photonic crystal waveguide is perpendicular to the axis of the silicon dielectric pillar (3) in the photonic crystal, and the optical axis of the defective dielectric pillar I (5) or the defective dielectric pillar II (8) is consistent with the direction of the silicon dielectric pillar (3).

7. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to any one of claims 4-6, characterized in that, The silicon dielectric pillars and background of the photonic crystal are composed of high refractive index material and low refractive index material, respectively; the high refractive index material is a medium with a refractive index of 3 or higher; the low refractive index material is a medium with a refractive index of less than 1.4; the defect dielectric pillar I (5) and defect dielectric pillar II (8) are made of oxide material with a refractive index of less than 2 and which is easy to form conductive filaments; the electrode is made of material that is easy to generate resistive switching effect.

8. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 7, characterized in that, The defect medium column I (5) is made of silicon dioxide, and the defect medium column II (8) is made of titanium dioxide; the electrode is a silver electrode or a copper electrode; the high refractive index material is silicon; and the low refractive index material is air.

9. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to any one of claims 4-6 and 8, characterized in that, The photonic crystal waveguide receives TE light from the input terminal (1), and the square wave signal generator (10) of the bias circuit outputs square wave signals with different polarities. The square wave signal controls the optical signal to be coupled into the output terminal I (2) through the resonant cavity I (4) and into the output terminal II (6) through the resonant cavity II (7). The two ends of the defect dielectric pillar are plated with electrochemical metal. When the square wave signal generator generates a square wave pulse that acts on the two ends of the electrode, a conductive filament will be formed in the defect dielectric pillar. The formation or breakage of the conductive filament changes the resonant frequency of the resonant cavity, thereby changing the output power of the output terminal and changing the state of the optical switch.

10. The dual-channel hexagonal lattice photonic crystal non-volatile optical switch based on resistive switching effect according to claim 9, characterized in that, The radius of the silicon dielectric pillar (3) is R=0.3a, the radius of the defect dielectric pillar is r=0.2a, and the waveguide width is d1=1.132a, where a is the lattice constant of the photonic crystal; the TE bandgap parameters in the photonic crystal are calculated by the plane wave expansion method, where the normalized light wave frequencies ωa / 2πc of the two TE bandgap range from 0.414 to 0.531 and from 0.631 to 0.744, respectively, where ω and c represent the angular frequency and the speed of light in free space, respectively; The operating wavelength ranges of the TE bandgap are 1.88a to 2.41a and 1.34a to 1.58a, respectively. The operating wavelength is adjusted by changing the lattice constant, the material and size of defect dielectric pillar I or defect dielectric pillar II. The extinction ratio of the optical switch is 10log (output power of the output port when on / output power of the output port when off).

Images