Electrochemically metallized square photonic crystal wavelength selective optical switch

Abstract

The application provides a square photonic crystal wavelength selective optical switch of electrochemical metallization, which comprises a photonic crystal, a plurality of silicon dielectric columns and a photonic crystal waveguide with a TE forbidden band, and the photonic crystal waveguide is located between the silicon dielectric columns; an input port of the input photonic crystal waveguide is provided with an input end, and the output port of the output photonic crystal waveguide is respectively provided with two output ends; the directions of the two output ends are opposite; the input end is perpendicular to the two output ends respectively; two resonant cavities are arranged between the input end and the two output ends I respectively; defect dielectric columns are arranged in the resonant cavities; and the two defect dielectric columns are connected with a bias circuit which provides a bias voltage. The application has the advantages of small structure volume, convenient integration, fast switch time response, high optical transmission efficiency and suitability for large-scale optical path integration; and the optical path switch function of different wavelengths can be realized in a certain wavelength range.

Description

Technical Field

[0001] This invention relates to the technical field of electro-controlled photonic crystal optical switches, and more particularly to an electrochemically metallized square photonic crystal non-volatile wavelength-selective optical switch. Background Technology

[0002] Photonics technology is gradually demonstrating its significant advantages in terms of bandwidth, capacity, and parallel processing capabilities. In communications, fiber optic communication has gradually replaced cable communication; with the development of wavelength division multiplexing (DWDM) technology and all-optical communication networks, optical switches have become an important component of optical communication technology, and their performance is crucial in determining node and network performance.

[0003] In optical communication, the production and usage costs of optical switching devices, as well as the full utilization of wavelength and spatial resources, are two important issues that need to be considered. Photonic crystal resonators, due to their excellent wavelength selectivity, flexible application structures, and ability to achieve various tunability methods, have been widely studied in filters, wavelength division multiplexers, optical modulators, optical switches, and lasers. Furthermore, the small size of photonic crystal structures offers significant advantages for applications requiring high integration density and low cost. Micro-devices based on photonic crystals, such as photonic crystal optical switches, are constructed by introducing point defects into the photonic crystal waveguide to create wavelength-selective optical switches. Through electrochemical metallization, applying a voltage across the dielectric pillar of the point defect allows it to form nanoscale metal filaments, thereby altering the position of the point defect. This change in the position of the point defect changes the resonant frequency of the corresponding resonant cavity, ultimately altering the transmittance of the photonic crystal waveguide, thus forming an electrochemically metallized photonic crystal wavelength-selective optical switch. Furthermore, the conductive filaments formed by electrochemical metallization possess excellent stability, remaining stable even after the external voltage is disconnected. Therefore, optical switches based on this principle exhibit non-volatility. Most existing wavelength-selective optical switches utilize microelectromechanical systems (MEMS) or liquid crystal materials, resulting in larger device structures and excessively high power consumption. Summary of the Invention

[0004] To address the technical problems of large structural size and high power consumption of existing wavelength-selective optical switches, this invention proposes an electrochemically metallized square photonic crystal non-volatile wavelength-selective optical switch, which has a small structural size, high efficiency, and is easy to integrate.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: an electrochemically metallized square photonic crystal wavelength-selective optical switch includes a photonic crystal, wherein the photonic crystal is provided with a plurality of silicon dielectric pillars and a photonic crystal waveguide with a TE bandgap, the photonic crystal waveguide being located 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, respectively, the directions of output terminal I and output terminal II being opposite, the input terminal being perpendicular to output terminal I and output terminal II, a resonant cavity I is provided between the input terminal and output terminal I, and a resonant cavity II is provided between the input terminal and output terminal II, a defective dielectric pillar I is provided in resonant cavity I, and a defective dielectric pillar II is provided in resonant cavity II, both the defective dielectric pillar I and the defective dielectric pillar II being connected to a bias circuit that provides a bias voltage.

[0006] Preferably, the bias circuit includes a square wave signal generator, and the electrodes of defective dielectric pillar I or defective dielectric pillar II are respectively connected to the square wave signal generator via wires.

[0007] Preferably, the photonic crystal is a two-dimensional square lattice photonic crystal; the silicon dielectric pillar is circular in shape.

[0008] Preferably, the center of the resonant cavity I is provided with a defective dielectric pillar I, and the center of the resonant cavity II is provided with a defective dielectric pillar II.

[0009] Preferably, the silicon dielectric pillars 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; the defect dielectric pillar I and defect dielectric pillar II are made of oxide materials with a refractive index greater than 2 and which are easy to form conductive filaments; the electrodes at both ends of the defect dielectric pillar I and defect dielectric pillar II are plated with a material that is easy to undergo electrochemical oxidation-reduction reactions.

[0010] Preferably, the defect dielectric column I is made of silicon dioxide and the defect dielectric column II is made of titanium dioxide; the electrodes at both ends of the defect dielectric column I and the defect dielectric column II are plated with silver or copper.

[0011] Preferably, the waveguide plane of the photonic crystal waveguide is perpendicular to the axis of the silicon dielectric pillar; the optical axes of the defect dielectric pillar I and the defect dielectric pillar II are aligned with the direction of the silicon dielectric pillar.

[0012] 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 are coupled into output terminal I through resonant cavity I and into output terminal II through resonant cavity II. When the square wave signal generated by the square wave signal generator acts on the two ends of the electrodes of the defective dielectric pillar I, conductive filaments are formed inside the defective dielectric pillar. The formation of the conductive filaments changes the resonant frequency of resonant cavity I, thereby changing the output power of output terminal I. When the square wave signal generated by the square wave signal generator acts on the two ends of the electrodes of the defective dielectric pillar II, conductive filaments are formed inside the defective dielectric pillar. The formation of the conductive filaments changes the resonant frequency of resonant cavity II, thereby changing the output power of output terminal II.

[0013] 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 of the photonic crystal waveguide is d1=1.4a, where a is the lattice constant of the photonic crystal; the frequencies of the two TE bandgap photonic crystal waveguides corresponding to output terminals I and II in the photonic crystal are calculated using the plane wave expansion method to be 0.41 to 0.513 (ωa / 2πc) and 0.232 to 0.302 (ωa / 2πc), respectively, where ω and c represent the angular frequency and the speed of light in free space, respectively.

[0014] Preferably, the two resonant cavities have different resonant frequencies, enabling different wavelengths to enter different channels, thereby achieving wavelength selection; the corresponding TE bandgap operating wavelength ranges are 1.949a to 2.44a and 3.31a to 4.31a, respectively; the output wavelength is related to the resonant wavelength of the resonant cavity. Without considering dispersion or with very small material dispersion changes, the resonant wavelength can be obtained by changing the lattice constant α, the material and thickness of the defect dielectric pillar, and so on, to obtain a wavelength value that satisfies the wavelength range in proportion to it; the operating wavelength is adjusted by changing the lattice constant and the material and size of the defect dielectric pillar.

[0015] Compared with existing technologies, the advantages of this invention are: small structural size, easy integration, fast switching time response, high optical transmission efficiency, and suitability for large-scale optical path integration; by applying the proportional scaling characteristics of photonic crystals and changing the lattice constant proportionally, optical path switching functions of different wavelengths can be achieved within a certain wavelength range. High extinction ratio and tunable operating wavelength allow for the operation of pulses with a certain spectral width, Gaussian light, light of different wavelengths, or light of multiple wavelengths simultaneously, which has significant practical implications. Wavelength selection function: Because the resonant frequency of the resonant cavity is adjustable, each channel of this device outputs a different wavelength, enabling wavelength-selective optical switching. Attached Figure Description

[0016] 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.

[0017] Figure 1 This is a schematic diagram of the planar structure of the present invention.

[0018] Figure 2 for Figure 1 The diagram shows a three-dimensional structure.

[0019] Figure 3 This is a diagram showing the distribution of structural parameters of the present invention.

[0020] Figure 4 This is a waveform diagram of the switch in this invention.

[0021] Figure 5 The transmission characteristics in the switching state of Embodiment 1 of the present invention are shown, wherein (a) is the output characteristic curve of output terminal I and (b) is the output characteristic curve of output terminal II.

[0022] Figure 6 This is a schematic diagram of the optical field distribution when the output terminal I of Embodiment 1 of the present invention is used as a switching channel, wherein (a) is the optical field distribution when the output terminal I is turned on, and (b) is the optical field distribution when the output port I is turned off.

[0023] Figure 7 This is a schematic diagram of the optical field distribution when the output terminal II of Embodiment 1 of the present invention is used as a switching channel, wherein (a) is the optical field distribution when the output terminal II is turned on, and (b) is the optical field distribution when the output port II is turned off.

[0024] Figure 8 The transmission characteristics in the switching state of Embodiment 2 of the present invention are shown, wherein (a) is the output characteristic curve of output terminal I and (b) is the output characteristic curve of output terminal II.

[0025] Figure 9 This is a schematic diagram of the light field distribution when the output terminal I of Embodiment 2 of the present invention is used as a switching channel, wherein (a) is the light field distribution when the output terminal I is turned on, and (b) is the light field distribution when the output port I is turned off.

[0026] Figure 10 This is a schematic diagram of the optical field distribution when the output terminal II of Embodiment 2 of the present invention is used as a switching channel, wherein (a) is the optical field distribution when the output terminal II is turned on, and (b) is the optical field distribution when the output port II is turned off.

[0027] 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

[0028] 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.

[0029] This invention proposes a wavelength-selective optical switch using an electrochemically metallized square photonic crystal, such as... Figure 1 The diagram shows a planar structure without external control circuitry, including a photonic crystal with a photonic crystal waveguide having a TE bandgap. The optical switch also includes an input terminal 1, two output terminals I2 and II6, a silicon dielectric pillar 3 as the background, two resonant cavities I4 and II7, and two defect dielectric pillars I5 and II8 with silver electrodes plated at both ends. The input photonic crystal waveguide port is input terminal 1, and the output photonic crystal waveguide ports are output terminals I2 and II6. The resonant cavities are located between the input and output photonic crystal waveguides. Input terminal 1 is perpendicular to output terminals I2 and II6, respectively, and the two resonant cavities are located between input terminal 1 and output terminals I2 and II6, respectively. The input terminal is located at the left end of the photonic crystal, and the two output terminals are located above and below the photonic crystal, respectively. The initial signal light of this device enters from the left input terminal 1, and outputs light waves from output terminals I2 and II6 respectively. A photonic crystal waveguide receives TE light from input terminal 1, and a square wave signal generator 10 outputs square wave signals of different polarities. These square wave signals serve as control signals and are coupled into the output terminals through the resonant cavity. Defective dielectric pillars I5 and II8 are located at the center of the two resonant cavities, respectively. Both ends of these defective dielectric pillars are plated with silver electrodes and connected to the square wave signal generator via wires. Figure 2 The diagram shows a wavelength-selective optical switch with external control circuitry. 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 connected to the two silver electrodes of the defective dielectric pillar I5 via wires 9; the two ends of the second square wave signal generator 10 are connected to the two silver electrodes of the defective dielectric pillar II8 via wires 9.

[0030] The photonic crystal is a two-dimensional cubic lattice photonic crystal. 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. In this case, the background is air, and the dielectric pillar 3 is a silicon dielectric pillar. The silicon dielectric pillar is circular in shape.

[0031] Defect dielectric pillar I5 is made of oxide materials such as silicon dioxide with a refractive index below 2, which readily form conductive filaments. Defect dielectric pillar II8 is made of oxide materials such as titanium dioxide with a refractive index greater than 2, which readily form conductive filaments. The electrodes plated at both ends of defect dielectric pillars I5 and II8 are made of materials such as silver and copper, which readily undergo electrochemical oxidation-reduction reactions.

[0032] like Figure 1 and Figure 3 The structural diagram shown uses a Cartesian coordinate system; the positive X-axis points horizontally to the right, the positive Y-axis points vertically upwards within the plane of the paper, and the positive Z-axis points outwards perpendicular to the paper. Figure 3 As shown, the relevant parameters of the device of the present invention are: a is the lattice constant of the photonic crystal, the radius of the silicon dielectric pillar R = 0.3a, the radius of the defect dielectric pillar r = 0.2a, and the waveguide width d1 of the photonic crystal waveguide = 1.4a.

[0033] The photonic crystal of this invention has a square lattice with a lattice constant of a and a silicon dielectric pillar radius of 0.3a. The TE bandgap structure in the photonic crystal is calculated using the plane wave expansion method, where the two TE bandgaps are 0.41 to 0.513 (ωa / 2πc) and 0.232 to 0.302 (ωa / 2πc), respectively. Light waves of any frequency within these bandgaps will be confined within the waveguide.

[0034] The photonic crystal waveguide used in this invention is formed by removing a portion of the silicon dielectric pillar. The waveguide plane is perpendicular to the axis of the silicon dielectric pillar in the photonic crystal. The resonant cavity is formed by removing the central background silicon dielectric pillar and adding a defective dielectric pillar. The optical axis of the defective dielectric pillar is aligned with the direction of the background silicon dielectric pillar.

[0035] 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 memory (RSM). Under the influence of an external electric field, the active electrodes of the RSM undergo an electrochemical oxidation-reduction reaction within the RSM's dielectric, ultimately forming 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 of the output port.

[0036] 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 ports. The output waveguide has relatively high optical power, and the switch is in the on state. Since the resonant frequencies of the different resonant cavities are different, the device can achieve the function of different wavelengths entering different channels, thereby achieving wavelength selection. When one of the square wave signal generators generates a positive square wave signal acting on 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 dielectric pillar. At this time, the resonant frequency of the resonant cavity changes, and the original wavelength cannot 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. Since the conductive filaments are relatively stable after formation, the switch will remain in the off state even without an external electric field. Thus, the switch possesses 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 within the defective dielectric will break off 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.

[0037] The lattice constant and operating wavelength can be determined using the following method, through the formula...

[0038] ;

[0039] Among them, λ, , These represent wavelength, normalized wavelength, and normalized frequency, respectively.

[0040] The normalized TE bandgap frequency range of the photonic crystal with a square lattice silicon structure in this invention fnorm The values ​​are 0.41 to 0.513 and 0.232 to 0.302 (ωa / 2πc), respectively. The corresponding TE bandgap wavelength ranges λ are calculated to be 1.949a to 2.44a and 3.31a to 4.31a, respectively. 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, wavelength values ​​that satisfy the wavelength range can be obtained proportionally by changing the lattice constant α, the material, and the thickness of the defect dielectric pillar. The operating wavelength can be adjusted by changing the lattice constant and the material and size of the defect dielectric pillar.

[0041] like Figure 4 As 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.

[0042] 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 when the switch is in the on and off states. Figure 5 It can be seen that at normalized light frequencies ωa / 2πc = 0.4405 and 0.2845, the switches of 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 the output channel I2 can reach 25.3 dB, and the extinction ratio of the output channel II6 can reach 20 dB.

[0043] Example 1

[0044] An electrochemically metallized square photonic crystal wavelength-selective optical switch can achieve optical switching functions of different wavelengths by proportionally changing the lattice constant, without considering dispersion or with very small material dispersion variations. Other parameters are set as follows: a = 0.4 μm, R = 0.3 a, r = 0.2 a, d1 = 1.4 a, and the normalized optical frequencies ωa / 2πc are 0.4405 and 0.2845, respectively. With other parameters unchanged, the output channel I2 corresponds to a 908 nm light wave, and the output channel II6 corresponds to a 1406 nm light wave. Simulation calculations yielded the output power of the output channel I2 in the on and off states corresponding to light waves in the vicinity of the normalized frequency 0.4405. Figure 5As shown in (a), the output power of the output channel II6, corresponding to the light wave in the range of near the normalized frequency of 0.2845 in both the on and off states, was calculated as follows. Figure 5 As shown in (b), the switching extinction ratio of output channel I2 can be calculated to be 25.3dB, and the switching extinction ratio of output channel II6 can be 20dB. Figure 6 and Figure 7 These are the electric field distribution diagrams for the output I2 channel and output II6 channel switches in the on and off states, respectively. Figure 5 It can be concluded that when the switch is in the open state, most of the energy passes through the device, and when the switch is closed, there is basically no crosstalk between the two channels.

[0045] Example 2

[0046] In this implementation, without considering dispersion or very small changes in material dispersion, different wavelengths of optical switching 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 = 1.4a, and the normalized optical frequency ωa / 2πc is 0.4404 and 0.2845, respectively. With other parameters unchanged, the output channel I2 corresponds to a 1021 nm light wave, and the output channel II6 corresponds to 1582 nm. Simulation calculations yield the output power of the output channel I2 in both the on and off states, corresponding to light waves in the range near the normalized frequency of 0.4405. Figure 8 As shown in (a), the output power of the output channel II6, corresponding to the light wave in the range of near the normalized frequency of 0.2845 in both the on and off states, was calculated as follows. Figure 8 As shown in (b). According to Figure 8 According to the data calculation, the switching extinction ratio of the output channel I2 can reach 25.4dB, and the switching extinction ratio of the output channel II6 can reach 19.6dB. Figure 9 and Figure 10 These are the electric field distribution diagrams for the output I2 channel and output II6 channel switches in the on and off states, respectively. Figure 9 and Figure 10 It can be concluded that when the switch is in the open state, most of the energy passes through the device, and when the switch is closed, there is basically no crosstalk between the two channels.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, 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. An electrochemically metallized square photonic crystal wavelength-selective optical switch, comprising a photonic crystal, characterized in that, The photonic crystal is provided with a plurality of silicon dielectric pillars (3) and a photonic crystal waveguide with a TE bandgap. The photonic crystal waveguide is located between the silicon dielectric pillars (3). The port of the input photonic crystal waveguide is provided with an input terminal (1), and the port of the output photonic crystal waveguide is provided with an output terminal I (2) and an output terminal II (6) respectively. The directions of the output terminal I (2) and the output terminal II (6) are opposite. The input terminal (1) is perpendicular to the output terminal I (2) and the output terminal II (6) respectively. A resonant cavity I (4) is provided between the input terminal (1) and the output terminal I (2). A resonant cavity II (7) is provided between the input terminal (1) and the output terminal II (6). A defective dielectric pillar I (5) is provided in the resonant cavity I (4), and a defective dielectric pillar II (8) is provided in the resonant cavity II (7). Both the defective dielectric pillar I (5) and the defective dielectric pillar II (8) are connected to a bias circuit that provides a bias voltage. 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 signals are 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). When the square wave signal generated by the square wave signal generator acts on the two ends of the electrodes of the defective dielectric pillar I (5), conductive filaments will be formed in the defective dielectric pillar. The formation of conductive filaments changes the resonant frequency of the resonant cavity I (4), thereby changing the output power of the output terminal I (2) respectively. When the square wave signal generated by the square wave signal generator acts on the two ends of the electrodes of the defective dielectric pillar II (8), conductive filaments will be formed in the defective dielectric pillar. The formation of conductive filaments changes the resonant frequency of the resonant cavity II (7), thereby changing the output power of the output terminal II (6) respectively.

2. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 1, characterized in that, The bias circuit includes a square wave signal generator (10), and the electrodes of defective dielectric pillar I (5) or defective dielectric pillar II (8) are connected to the square wave signal generator (10) respectively through wires (9).

3. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 1 or 2, characterized in that, The photonic crystal is a two-dimensional square lattice photonic crystal; the silicon dielectric pillar (3) is circular in shape.

4. The electrochemically metallized square photonic crystal non-volatile wavelength-selective optical switch according to claim 3, characterized in that, The center of the resonant cavity I (4) is provided with a defective dielectric pillar I (5), and the center of the resonant cavity II (7) is provided with a defective dielectric pillar II (8).

5. The electrochemically metallized square photonic crystal non-volatile wavelength-selective optical switch according to claim 4, 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 greater than 2 and which is easy to form conductive filaments; the electrodes at both ends of the defect dielectric pillar I (5) and defect dielectric pillar II (8) are plated with a material that is easy to undergo electrochemical oxidation-reduction reaction.

6. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 5, 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 electrodes at both ends of the defect medium column I (5) and the defect medium column II (8) are plated with silver or copper; the high refractive index material is silicon; and the low refractive index material is air.

7. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 4, 5, or 6, characterized in that, The waveguide plane of the photonic crystal waveguide is perpendicular to the axis of the silicon dielectric pillar; the optical axes of the defect dielectric pillar I (5) and the defect dielectric pillar II (8) are in the same direction as the silicon dielectric pillar.

8. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 1, characterized in that, 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 of the photonic crystal waveguide is d1=1.4a, where a is the lattice constant of the photonic crystal. The normalized optical frequencies ωa / 2πc of the two TE bandgap photonic crystal waveguides corresponding to the output terminals I (2) and II (6) in the photonic crystal are calculated by plane wave expansion method to be 0.41 to 0.513 and 0.232 to 0.302, respectively, where ω and c represent the angular frequency and the speed of light in free space, respectively.

9. The electrochemically metallized square photonic crystal wavelength-selective optical switch according to claim 8, characterized in that, The two resonant cavities have different resonant frequencies, enabling different wavelengths to enter different channels, thus achieving wavelength selection. The corresponding TE bandgap operating wavelength ranges are 1.949a to 2.44a and 3.31a to 4.31a, respectively. The output wavelength is related to the resonant wavelength of the resonant cavity. Without considering dispersion or with very small material dispersion changes, the resonant wavelength can be obtained by changing the lattice constant α, the material and thickness of the defect dielectric pillar, and so on, to obtain a wavelength value that satisfies the wavelength range in proportion to it. The operating wavelength is adjusted by changing the lattice constant and the material and size of the defect dielectric pillar.

Images