Mems optical switch and optical cross-connect

Abstract

The application discloses a MEMS optical switch and an optical cross connector, the MEMS optical switch comprising a frame and a super-structured surface lens located in the frame, the super-structured surface lens being used for adjusting a phase; the super-structured surface lens is connected with the frame through a plurality of groups of oppositely arranged connecting structures; wherein the super-structured surface lens comprises a substrate and a plurality of sub-wavelength structure units which are arrayed on the substrate, the sub-wavelength structure units comprising a plurality of micro-nano columns which are of the same height and different sizes, and the super-structured surface lens is used for collimating and deflecting an incident light beam incident thereon to be transmitted to a target port. The application can simultaneously realize the collimation and deflection functions of an optical path by using the super-structured surface lens, is convenient to control, reduces the required elements of the optical switch device, and reduces the volume of the overall device.

Description

Technical Field

[0001] This invention belongs to the field of optical cross connector technology, specifically relating to a MEMS optical switch and an optical cross connector. Background Technology

[0002] All-optical networks represent the future direction of network communication systems. They utilize optical devices instead of traditional electronic components to achieve everything from optical signal generation, modulation, and transmission to reception, detection, and demodulation. Among these challenges, achieving full optical connectivity for network switching nodes remains a hurdle to overcome in the field of all-optical communication. Optical cross-connects (OXCs), which allow switching of communication light from input ports to arbitrary output ports, are one solution for node configuration in future meshed network architectures. Leveraging the miniaturization, integration, and high sensitivity of MEMS micromirrors, the core component of optical cross-connects—the optical switch—can be constructed using a MEMS platform.

[0003] Most existing free-space optical switches employ micromirror arrays, using optical micromirrors or arrays of optical micromirrors to change the propagation direction of the light beam and switch the optical path. Traditional micromirror arrays widely use single driving methods such as electrothermal, electromagnetic, electrostatic, and piezoelectric, which place high demands on the large rotation angles, stability, responsivity, and reliability of MEMS micromirrors. A few optical switch schemes also use transmissive mirror arrays, employing lenses as deflection elements in the optical switch path. This can significantly reduce the optical system complexity of traditional mirrors, thereby reducing the number of components requiring coupling and decreasing insertion loss. For example, electrostatic MEMS driving can be used to realize the operation of a 9x9 optical switch array.

[0004] The common thread among the above solutions is the use of MEMS as the driving platform for optical components. MEMS (Micro-Electro-Mechanical Systems) technology combines micro-mechanical structures with electronic devices. It utilizes microfabrication processes to manufacture micro-mechanical parts and sensors, along with their corresponding electronic control components, thereby realizing miniaturized and integrated mechanical systems. Thanks to the rapid development of micro-nano fabrication technology, MEMS technology has been widely applied in fields such as automotive, consumer electronics, medical, and industrial automation.

[0005] Most existing optical switching devices use lenses and micromirror arrays as modulation elements for fiber optic signals. Such optical switches mainly suffer from the following problems:

[0006] 1. Numerous optical system components. A micromirror array optical switch system requires at least five optical components, including an input fiber, an input lens, a mirror, an output lens, and an output fiber. If expansion to a multi-port, high-capacity optical cross connector is needed, multiple mirrors may even need to be cascaded and aligned.

[0007] 2. High difficulty in component alignment. The alignment and coupling of optical fiber signals from the transmitter to the receiver involves up to 30 degrees of freedom between the input fiber, input lens, reflector, output lens, and output fiber, which greatly increases the difficulty of alignment and causes insertion loss and coupling loss during signal transmission.

[0008] 3. The optical switching device is large in size. Due to the inclusion of more optical components in the system and the requirements for optical path length during beam coupling, the overall device size is relatively large.

[0009] For systems that use lenses as optical path conversion elements, the main problems are that these lenses are limited by aberrations, have small deflection angles, require high lens quality, have limited optical performance, have limited expansion potential, and have high coupling loss.

[0010] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0011] The purpose of this invention is to provide a MEMS optical switch and optical cross connector, which can simultaneously achieve optical path collimation and deflection functions using metasurface lenses, making it easy to control, reducing the number of components required for optical switch devices, and reducing the overall device size.

[0012] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0013] A MEMS optical switch includes a frame and a metasurface lens located within the frame. The metasurface lens is used to adjust the phase. The metasurface lens is connected to the frame through several sets of relatively arranged connection structures. The metasurface lens includes a substrate and subwavelength structural units distributed in an array on the substrate. The subwavelength structural units include multiple micro / nano pillars of the same height but different sizes. The metasurface lens is used to collimate and deflect an incident light beam incident on it to transmit to a target port.

[0014] In one or more embodiments of the present invention, the phase distribution of the metasurface lens is determined by at least three parameters: the wavelength of the incident beam, the focal length of the metasurface lens, and the position of the subwavelength structural unit on the metasurface lens.

[0015] In one or more embodiments of the present invention, the phase distribution of the metasurface lens satisfies the equation:

[0016] Where λ is the wavelength of the incident beam, f is the focal length of the metasurface lens, and r is the position of the subwavelength structural unit on the metasurface lens; and / or,

[0017] The phase distribution of the metasurface lens satisfies the equation:

[0018] Where λ is the wavelength of the incident beam, f is the focal length of the metasurface lens, and r is the position of the subwavelength structural unit on the metasurface lens.

[0019] In one or more embodiments of the present invention, the substrate is made of quartz; and / or,

[0020] The material of the subwavelength structural unit is one or more of amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride, and gallium nitride.

[0021] In one or more embodiments of the present invention, the connection structure includes a thermal drive unit connected to the frame and a connecting beam connecting the thermal drive unit and the metasurface lens, wherein the thermal drive unit is arranged in an axisymmetric manner.

[0022] In one or more embodiments of the present invention, the MEMS optical switch further includes a permanent magnet located below the thermal drive unit.

[0023] In one or more embodiments of the present invention, the short axis direction of the permanent magnet is parallel to the symmetry axis direction of the thermal drive unit.

[0024] In one or more embodiments of the present invention, the thermal drive unit includes a first thermal drive beam and a second thermal drive beam symmetrically arranged, and a connecting rod located between the first thermal drive beam and the second thermal drive beam. The first ends of the first thermal drive beam and the second thermal drive beam are both connected to the frame, and the second ends of the first thermal drive beam and the second thermal drive beam are both connected to the connecting beam.

[0025] In one or more embodiments of the present invention, an angle is formed between the first thermally driven beam and the second thermally driven beam, the angle being 165° to 175°; and / or,

[0026] The number of the first thermally driven beam and the second thermally driven beam are equal and there are multiple of each. The multiple first thermally driven beams and the multiple second thermally driven beams are connected in series by wires.

[0027] The material of the first thermally driven beam and / or the second thermally driven beam and / or the connecting rod is one or more of Cu, W, NiCr alloy, heavily doped n-type Si, and Al.

[0028] In one or more embodiments of the present invention, the connecting beam is arranged in a detour, the connecting beam includes a plurality of first detour segments and a plurality of second detour segments, the length direction of the first detour segments is parallel to the symmetry axis direction of the thermal drive unit, and the length direction of the second detour segments is perpendicular to the symmetry axis direction of the thermal drive unit.

[0029] Another specific embodiment of the present invention provides the following technical solution:

[0030] An optical cross connector includes an input optical fiber, a first MEMS optical switch, a second MEMS optical switch, and an output optical fiber arranged sequentially, wherein the first MEMS optical switch and the second MEMS optical switch are as described above.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention provides a MEMS optical switch and optical cross connector that combines cutting-edge metasurface technology with optical switch technology. It utilizes metasurface lenses to simultaneously achieve optical path collimation and deflection functions. Not only does it have better optical performance than traditional lenses, but more importantly, the optical function design of metasurface lenses is more flexible, and it has great potential and room for expansion in the field of optical communication.

[0033] The coupling drive method adopted in this invention is a combination of electromagnetic drive and thermal drive. The fast response speed of electromagnetic drive is used to make up for the slow response speed of thermal drive. At the same time, since the thermal drive unit itself has a large current density when Joule heating is generated, the Lorentz force contributes a considerable amount to the output displacement. On the basis of large output displacement, it can also provide a precise alignment function. Attached Figure Description

[0034] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a MEMS optical switch in one embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of a metasurface lens in one embodiment of the present invention;

[0037] Figure 3 This is a curve showing the relationship between the size, phase, and transmittance of a metasurface lens in one embodiment of the present invention;

[0038] Figure 4 for Figure 1 Enlarged view of the local structure at point A;

[0039] Figure 5 This is a schematic diagram of the structure of a MEMS optical switch after thermal and electromagnetic driving in one embodiment of the present invention;

[0040] Figure 6 for Figure 1 Enlarged view of the local structure at point B;

[0041] Figure 7 This is a side view of the structure of a MEMS optical switch in one embodiment of the present invention;

[0042] Figure 8 This is a schematic diagram of the optical cross connector in another embodiment of the present invention;

[0043] Figure 9 This is a simulation result of OXC for beam deflection using a metasurface lens to achieve 49 output ports, as shown in another embodiment of the present invention.

[0044] Figure 10 This is a simulation result of the beam deflection intensity distribution of a metasurface lens in another embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0048] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0049] Reference Figure 1 , Figure 2As shown, in one embodiment of the present invention, a MEMS optical switch includes a frame 1 and a metasurface lens 2 located within the frame 1. The metasurface lens 2 is used to adjust the phase. The metasurface lens 2 is connected to the frame 1 through several sets of relatively arranged connection structures 3. The metasurface lens 2 includes a substrate 21 and subwavelength structural units 22 arrayed on the substrate 21. The subwavelength structural units 22 are micro-nano pillars of the same height but different sizes.

[0050] It should be explained that the fiber optic signal, upon entering free space, becomes a divergent beam with a communication wavelength of 1550 nm. After propagating a distance, this divergent beam becomes the incident beam and strikes the metasurface lens 2 of the MEMS optical switch, forming a light spot. This light spot covers multiple subwavelength structural units 22, with different sizes of these units at different locations, thus allowing for different phase modulation effects on the light spot. The metasurface lens 2 is driven by the connecting structure 3, enabling its adjustable position. After the divergent beam emitted from the fiber is transmitted through the metasurface lens 2, the output beam becomes a collimated beam, and its propagation direction is deflected and coupled to the target port, thereby achieving the optical routing function.

[0051] Based on this design, the MEMS optical switch in this embodiment can simultaneously achieve the functions of optical path collimation and deflection through the metasurface lens 2, which facilitates control, reduces the number of components required for the optical switch device, and reduces the overall device size.

[0052] Specifically, the phase distribution of the metasurface lens 2 in this embodiment satisfies the equation:

[0053]

[0054] Where λ is the wavelength of light, f is the focal length of the metasurface lens 2, and r is the position of the subwavelength structural unit 22 on the metasurface lens 2.

[0055] Of course, this application is not limited to this; the phase distribution of the metasurface lens 2 can also satisfy other different equations. For example, the phase distribution of the metasurface lens 2 satisfies the following equation:

[0056]

[0057] Where λ is the wavelength of the incident beam, f is the focal length of the metasurface lens, and r is the position of the subwavelength structural unit on the metasurface lens.

[0058] Specifically, the correspondence between different sizes of the subwavelength structural unit 22 and its phase and transmittance in this embodiment is as follows: Figure 3As shown, this invention determines the phase distribution based on the light wavelength and the focal length of the metasurface lens 2, and then maps the phase distribution to the size distribution of the subwavelength structural unit 22 according to the corresponding relationship, thereby obtaining the fabrication pattern of the metasurface lens 2. The dashed lines represent the transmittance, and the solid lines represent the phase. For example, when the equivalent size of the subwavelength structural unit 22 is approximately 350 nm, the transmittance of the metasurface lens 2 covered by the light spot is minimal, and the phase is approximately -0.5 rad. Due to the low transmittance, these sizes should be avoided when selecting the subwavelength structural unit 22. The phase of light refers to the alternating waveform changes exhibited by photon vibrations as the light wave propagates. Since light is an electromagnetic wave, its photon vibrations are perpendicular to both magnetic vibrations and the direction of wave propagation, resulting in waveform changes during propagation. When the same light wave passes through materials with different refractive indices, the phase of the light changes, and the wavelength and amplitude also change. Therefore, the metasurface lens 2 fabricated in this way can meet the collimation and deflection requirements of light beams of corresponding wavelengths.

[0059] Given the transmittance requirements of the diverging beam for the metasurface lens 2, the substrate 21 in this embodiment may optionally be made of quartz, or other materials with high transmittance such as glass. Alternatively, the subwavelength structural unit 22 in this embodiment may be made of one or more of amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride, and gallium nitride. Amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride, and gallium nitride all have high transmittance.

[0060] To facilitate the movement of the micromirrors and achieve an adjustable position, conventional driving methods for MEMS optical switches in the prior art include:

[0061] 1. Electrostatic Actuation: This method utilizes an external voltage applied to the micromirror to achieve vibration and motion through an electric field. Voltage-driven methods typically employ adjustable voltage sources or drive circuits, enabling control over the application of different vibration frequencies and amplitudes to the micromirror.

[0062] 2. Thermally driven: This method utilizes temperature changes caused by thermal effects to drive the micromirror. For example, it can be achieved by using a combination of materials with different coefficients of thermal expansion or by using electrothermal devices to control the micromirror.

[0063] 3. Pressure-driven: This method uses the pressure of gas or liquid to drive the micromirror. For example, a micropump or microfluidic system can be used to apply pressure, thereby controlling and moving the micromirror.

[0064] 4. Electromagnetic Drive: This method uses an external magnetic field to apply force to the micromirror, thereby achieving its vibration and movement. Electromagnetic actuators or permanent magnet actuators are typically used to provide a stable magnetic field, and the micromirror is controlled by changing the direction and magnitude of the magnetic field. In practical applications, different MEMS driving methods should be rationally selected based on different application scenarios and process conditions, and the micromirror should be designed in conjunction with the driving objectives.

[0065] Reference Figure 1 As shown, the connection structure 3 in this embodiment includes a thermal drive unit 31 connected to the frame 1 and a connecting beam 32 connecting the thermal drive unit 31 and the metasurface lens 2. The thermal drive unit 31 is arranged axially symmetrically. Based on this design, the metasurface lens 2 can be driven by thermal drive, which has advantages such as large driving displacement, large driving force output, and low driving voltage.

[0066] Specifically, refer to Figure 4 As shown, the thermal drive unit 31 in this embodiment includes a symmetrically arranged first thermal drive beam 311 and second thermal drive beam 312, and a connecting rod 313 located between the first thermal drive beam 311 and the second thermal drive beam. The first ends of both the first thermal drive beam 311 and the second thermal drive beam 312 are connected to the frame 1, and the second ends of both the first thermal drive beam 311 and the second thermal drive beam 312 are connected to the connecting beam 32. The thermal drive unit 31 is V-shaped, with the pointed end of the V-shape pointing towards the metasurface lens 2. (Refer to...) Figure 5 As shown, to achieve thermal actuation, current needs to be passed through the first thermal actuation beam 311, the second thermal actuation beam 312, and the connecting rod 313. The current passing through the first and second thermal actuation beams 311 and 312 will generate Joule heat, causing them to expand in volume. Since the equivalent stiffness of the V-shaped thermal actuation unit 31 perpendicular to the length of the connecting rod 313 is much smaller than the equivalent stiffness along the length of the connecting rod 313, this small thermal expansion can be converted into displacement along the length of the connecting rod 313, thus enabling the displacement of the metasurface lens 2 through thermal actuation.

[0067] Its basic principle can be expressed as:

[0068] Q e =J·E

[0069] ε=α(T)(TT ref )

[0070] Among them, Q e J is the Joule heat, J is the current density, E is the electric field strength, ε is the strain, α is the coefficient of thermal expansion, and T is the thermodynamic temperature. ref That is the initial temperature.

[0071] Optionally, to amplify the displacement of the metasurface lens 2, refer to Figure 4 As shown, in this embodiment, the number of first thermally driven beams 311 and second thermally driven beams 312 are equal, and multiple of each are provided. The multiple first thermally driven beams 311 and multiple second thermally driven beams 312 are connected in series by wires. According to this design, when the thermally driven unit 31 is energized, more thermal expansion can be generated, thereby increasing the displacement in the length direction of the connecting rod 313.

[0072] Since the angle between the first thermally driven beam 311 and the second thermally driven beam is an important design parameter, the larger the angle, the greater the output driving force; conversely, the smaller the angle, the smaller the driving force, but the significantly increased the output displacement. Therefore, optionally, in this embodiment, the first thermally driven beam 311 and the second thermally driven beam 312 are symmetrically arranged along the length of the connecting rod 313, forming an angle of 170° between them. Of course, this angle can also be 165°, 175°, or 165°~175°.

[0073] Optionally, due to requirements on electrical resistance and coefficient of thermal expansion, at least one of the first thermally driven beam 311, the second thermally driven beam 312, and the connecting rod 313 in this embodiment is made of one or more of Cu, W, NiCr alloy, heavily doped n-type Si, and Al. These materials have high electrical conductivity and a high coefficient of thermal expansion.

[0074] Reference Figure 5 As shown, the outer edge of the MEMS optical switch in this embodiment is roughly square. Four thermal drive units 31 are provided. The metasurface lens 2 is connected to the frame 1 via two thermal drive units 31 arranged along the horizontal axis and two thermal drive units 31 arranged along the vertical axis. Therefore, the thermal drive units 31 can provide displacement adjustment of the metasurface lens 2 in four directions: up, down, left, and right.

[0075] Optional, refer to Figure 6As shown, the connecting beam 32 in this embodiment is arranged in a circuitous manner. The connecting beam 32 includes multiple first circuitous segments 321 and multiple second circuitous segments 322. The length direction of the first circuitous segment 321 is parallel to the symmetry axis direction of the thermal drive unit 31, and the length direction of the second circuitous segment 322 is perpendicular to the symmetry axis direction of the thermal drive unit 31. The connecting beam 32 has a circuitous structure. Based on this design, the thermal drive unit 31 and the metasurface lens 2 can be connected through the connecting beam 32, thereby achieving greater stiffness in the length direction and less stiffness in the width direction of the connecting beam 32. When current is applied to one of the thermal drive units 31, the thermal drive unit 31 expands in volume, generating a large output displacement in the length direction of the connecting beam 32. Since no current is applied to other thermal drive units 31, the other thermal drive beams do not generate significant damping, thus affecting the output displacement. This allows for the adjustment of the length direction of the connecting beam 32 connected to the current-applied thermal drive unit 31 within the same frame 1. Understandably, when current is applied to multiple thermal drive units 31, independent motion adjustment with multiple degrees of freedom can be achieved within the same frame 1.

[0076] Preferably, refer to Figure 7 and combined Figure 5 As shown, due to the slow response and high power consumption of thermal drive, it is difficult to control precisely. Therefore, the MEMS optical switch in this embodiment also includes a permanent magnet 4 located below the thermal drive unit 31. By adding the permanent magnet 4 to generate a Lorentz force in the current-carrying conductor, the Lorentz force has a fast response and is easy to control, thus facilitating precise alignment of the micromirrors. Given the large current intensity in the thermal drive unit 31, placing the permanent magnet 4 directly below the thermal drive unit 31 generates a large Lorentz force. The fast-responding Lorentz force provides the initial driving force for thermal drive, thereby compensating for the slow response of thermal drive. In addition, the Lorentz force can also provide an important function for fine-tuning during fiber optic signal alignment.

[0077] Its basic principle can be expressed as:

[0078] |F|=|IL×B|=BIL·sinθ

[0079] Where F is the Lorentz force, I is the current intensity, L is the conductor length, B is the magnetic flux density, and θ is the angle between the conductor and the direction of the magnetic flux density.

[0080] When a voltage is applied to both ends of the thermal drive unit 31, a large current density will first generate a Lorentz force parallel to the direction of the connecting rod 313. As Joule heating is generated, the temperature of the thermal drive unit 31 will rise rapidly. Since both ends of the thermal drive unit 31 are connected to the frame 1, the thermal expansion of the thermal drive unit 31 can only be released in the direction of the middle connecting rod 313. Since both the first thermal drive beam 311 and the second thermal drive beam 312 have an angle with the connecting rod 313, this thermal expansion will be converted into an output displacement in the length direction of the connecting rod 313. Through the connected meandering connecting beam 32, the output displacement is converted into the in-plane translation of the metasurface lens 2.

[0081] In order to apply the generated Lorentz force to the thermal drive unit 31, the minor axis of the permanent magnet 4 in this embodiment is parallel to the axis of symmetry of the thermal drive unit 31. Based on this design, the thermal expansion direction of the thermal drive unit 31 is the same as the direction of the Lorentz force, which is more conducive to achieving precise adjustment of the metasurface lens 2.

[0082] Reference Figure 8 As shown, another embodiment of the optical cross-connector of the present invention includes an input optical fiber 5, a first MEMS optical switch 101, a second MEMS optical switch 102, and an output optical fiber (not shown in the figures), arranged sequentially. The first MEMS optical switch 101 and the second MEMS optical switch 102 are as shown in the above embodiment. In one embodiment, the optical cross-connector includes 49 ports, each port having an input optical fiber 5, a first MEMS optical switch 101, a second MEMS optical switch 102, and an output optical fiber arranged sequentially. Figure 9 As shown in the figure, each circular spot represents the output beam when the metasurface lens 2 is displaced to a specific position. The intensity distribution curves of the multiple output beams obtained by multiple metasurface lenses 2 are shown in the figure. Figure 10 As shown in the figure, each peak represents the intensity distribution of the corresponding output beam on the second MEMS optical switch 102, and the intensity distribution curve exhibits a Gaussian distribution. The results demonstrate that the metasurface lens 2 used in this invention can simultaneously replace the functions of the collimating lens and the reflecting mirror in a traditional optical switch. It possesses the deflection angle and lightweight characteristics that can be replaced or even surpassed by traditional optical lenses, integrating optical signal collimation and optical path deflection functions into one, effectively reducing the complexity of traditional optical switch systems.

[0083] As can be seen from the above technical solutions, the present invention has the following beneficial effects:

[0084] This invention provides a MEMS optical switch and optical cross connector that combines cutting-edge metasurface technology with optical switch technology. It utilizes metasurface lenses to simultaneously achieve optical path collimation and deflection functions. Not only does it have better optical performance than traditional lenses, but more importantly, the optical function design of metasurface lenses is more flexible, and it has great potential and room for expansion in the field of optical communication.

[0085] The coupling drive method adopted in this invention is a combination of electromagnetic drive and thermal drive. The fast response speed of electromagnetic drive is used to make up for the slow response speed of thermal drive. At the same time, since the thermal drive unit itself has a large current density when Joule heating is generated, the Lorentz force contributes a considerable amount to the output displacement. On the basis of large output displacement, it can also provide a precise alignment function.

[0086] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0087] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A MEMS optical switch, characterized in that, The MEMS optical switch includes a frame and a metasurface lens located within the frame. The metasurface lens is used to adjust the phase. The metasurface lens is connected to the frame through several sets of relatively arranged connection structures. The metasurface lens includes a substrate and subwavelength structural units distributed in an array on the substrate. The subwavelength structural units include multiple micro / nano pillars of the same height but different sizes. The metasurface lens is used to collimate and deflect the incident light beam incident on it to transmit to the target port. The phase distribution of the metasurface lens satisfies the equation: Where λ is the wavelength of the incident beam, f is the focal length of the metasurface lens, and r is the position of the subwavelength structural unit on the metasurface lens; and / or, The phase distribution of the metasurface lens satisfies the equation: , where λ is the wavelength of the incident beam, f is the focal length of the metasurface lens, and r is the position of the subwavelength structural unit on the metasurface lens; The connection structure includes a thermal drive unit connected to the frame and a connecting beam connecting the thermal drive unit and the metasurface lens. The thermal drive unit is arranged in an axisymmetric manner. The MEMS optical switch also includes a permanent magnet located below the thermal drive unit; The short axis of the permanent magnet is parallel to the symmetry axis of the thermal drive unit; The thermal drive unit includes a first thermal drive beam and a second thermal drive beam arranged symmetrically, and a connecting rod located between the first thermal drive beam and the second thermal drive beam. The first ends of the first thermal drive beam and the second thermal drive beam are both connected to the frame, and the second ends of the first thermal drive beam and the second thermal drive beam are both connected to the connecting beam. An angle is formed between the first thermally driven beam and the second thermally driven beam, the angle being 165° to 175°; The connecting beam is arranged in a detour, and the connecting beam includes multiple first detour segments and multiple second detour segments. The length direction of the first detour segment is parallel to the symmetry axis direction of the thermal drive unit, and the length direction of the second detour segment is perpendicular to the symmetry axis direction of the thermal drive unit.

2. The MEMS optical switch according to claim 1, characterized in that, The substrate is made of quartz; and / or, The material of the subwavelength structural unit is one or more of amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride, and gallium nitride.

3. The MEMS optical switch according to claim 1, characterized in that, The number of the first thermally driven beam and the second thermally driven beam are equal and there are multiple of each. The multiple first thermally driven beams and the multiple second thermally driven beams are connected in series by wires. The material of the first thermally driven beam and / or the second thermally driven beam and / or the connecting rod is one or more of Cu, W, NiCr alloy, heavily doped n-type Si, and Al.

4. An optical cross connector, characterized in that, The optical cross connector includes an input optical fiber, a first MEMS optical switch, a second MEMS optical switch, and an output optical fiber arranged sequentially, wherein the first MEMS optical switch and the second MEMS optical switch are both as described in any one of claims 1 to 3.

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