CN117891062A - MEMS optical switch and optical cross-connect - Google Patents
MEMS optical switch and optical cross-connect Download PDFInfo
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Abstract
The invention discloses an MEMS optical switch and an optical cross connector, wherein the MEMS optical switch comprises a frame and an ultra-structured surface lens positioned in the frame, and the ultra-structured surface lens is used for adjusting the phase; the super-structured surface lens is connected with the frame through a plurality of groups of connecting structures which are oppositely arranged; the super-structured surface lens comprises a substrate and sub-wavelength structural units distributed on the substrate in an array mode, wherein the sub-wavelength structural units comprise a plurality of micro-nano columns with the same height and different sizes, and the super-structured surface lens is used for collimating and deflecting incident light beams incident on the super-structured surface lens to transmit the incident light beams to a target port. The invention can realize the collimation and deflection functions of the light path simultaneously by utilizing the super-structured surface lens, is convenient for regulation and control, reduces the elements required by the optical switching device and reduces the volume of the whole device.
Description
Technical Field
The invention belongs to the technical field of optical cross connectors, and particularly relates to an MEMS optical switch and an optical cross connector.
Background
An all-optical network is a development direction of a future network communication system, and an optical device is adopted to replace a traditional electronic device, so that the generation, the modulation, the transmission, the receiving, the detection and the demodulation of optical signals are realized. The network switching node is still a difficult problem to be solved in the field of all-optical communication, and optical cross-connect (OXC) capable of switching communication light from an input port to any output port is one of schemes for solving node configuration in a future meshed network group. The MEMS platform can be utilized to construct a core part of optical cross connection, namely an optical switch, due to the advantages of miniaturization, integration, high sensitivity and the like of the MEMS micro mirror.
The existing free space optical switch mostly adopts a micro-mirror array scheme, adopts an optical micro-mirror or an optical micro-mirror array to change the propagation direction of light beams to realize the switching of light paths, and the traditional micro-mirror array widely adopts single driving modes such as electric heating, electromagnetism, static electricity, piezoelectricity and the like, so that the traditional micro-mirror array has higher requirements on the aspects of large rotation angle, stability, responsivity and reliability of MEMS micro-mirrors. There are also few optical switching schemes using a transmissive mirror array, and using lenses as optical path deflecting elements of the optical switch can well reduce the complexity of the optical system of the conventional mirror, thereby reducing the number of elements to be coupled and reducing the insertion loss. The operation of the 9x9 optical switch array is achieved, for example, with electrostatic mes driving.
The common point of the above schemes is that MEMS (Micro-Electro-MECHANICAL SYSTEMS, micro-Electro-mechanical system) technology is a technology combining a Micro-mechanical structure with an electronic device, and utilizes a Micro-machining process to manufacture Micro-mechanical components and sensors, and electronic control components matched with the Micro-mechanical components, so that a miniaturized and integrated mechanical system is realized. Thanks to the rapid development of micro-nano processing technology, MEMS technology has been widely used in the fields of automobiles, consumer electronics, medical treatment, industrial automation, etc.
The conventional optical switching device mostly adopts a lens and micro-mirror array as a modulating element of an optical fiber signal, and the following problems are mainly existed for the optical switching device:
1. The optical system has many elements. At least five optical elements are needed for a micro-mirror array optical switching system, including an input optical fiber, an input lens, a mirror, an output lens and an output optical fiber, and even a plurality of mirrors are needed to be aligned in cascade if a multi-port high-capacity optical cross-connect is needed to be expanded;
2. The difficulty of component alignment is high. The optical fiber signals from the transmitting end to the receiving end relate to alignment coupling of up to 30 degrees of freedom in total among an input optical fiber, an input lens, a reflecting mirror, an output lens and an output optical fiber, so that alignment difficulty is greatly increased, and insertion loss and coupling loss in the signal transmission process are caused;
3. The optical switching device is bulky. Because the system comprises more optical elements and the requirement for the optical path in the light beam coupling process, the whole device is large in size.
For a system adopting a lens as an optical path conversion element, the traditional optical lens is mainly used, so that the lens is limited by aberration, the deflection angle is small, the requirement on the quality of the lens is high, the optical performance is single in type, the expandable space is small, and the coupling loss is high.
The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.
Disclosure of Invention
The invention aims to provide an MEMS optical switch and an optical cross connector, which can utilize a super-structure surface lens to realize the collimation and deflection functions of an optical path at the same time, are convenient to regulate and control, reduce elements required by an optical switch device and reduce the volume of the whole device.
In order to achieve the above object, a specific embodiment of the present invention provides the following technical solution:
a MEMS optical switch comprising a frame and a super-structured surface lens within the frame for adjusting phase; the super-structured surface lens is connected with the frame through a plurality of groups of connecting structures which are oppositely arranged; the super-structured surface lens comprises a substrate and sub-wavelength structural units distributed on the substrate in an array mode, wherein the sub-wavelength structural units comprise a plurality of micro-nano columns with the same height and different sizes, and the super-structured surface lens is used for collimating and deflecting incident light beams incident on the super-structured surface lens to transmit the incident light beams to a target port.
In one or more embodiments of the present invention, the phase distribution of the super-structured surface lens is determined by at least three parameters, namely, the wavelength of the incident light beam, the focal length of the super-structured surface lens, and the location of the sub-wavelength structural units on the super-structured surface lens.
In one or more embodiments of the invention, the phase profile of the super-structured surface lens satisfies the equation:
Where λ is the wavelength of the incident beam, f is the focal length of the super-structured surface lens, and r is the position of the sub-wavelength structural unit on the super-structured surface lens; and/or the number of the groups of groups,
The phase distribution of the super-structured surface lens satisfies the equation:
Where λ is the wavelength of the incident beam, f is the focal length of the super-structured surface lens, and r is the position of the sub-wavelength building block on the super-structured surface lens.
In one or more embodiments of the invention, the substrate is made of quartz; and/or the number of the groups of groups,
The material of the sub-wavelength structural unit adopts one or more of amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride and gallium nitride.
In one or more embodiments of the present invention, the connection structure includes a thermal driving unit connected to the frame and a connection beam connecting the thermal driving unit and the super-structured surface lens, the thermal driving unit being disposed in axial symmetry.
In one or more embodiments of the invention, the MEMS optical switch further comprises a permanent magnet located below the thermal drive unit.
In one or more embodiments of the invention, the short axis direction of the permanent magnet is parallel to the symmetry axis direction of the thermal drive unit.
In one or more embodiments of the present invention, the thermal driving unit includes a first thermal driving beam and a second thermal driving beam which are symmetrically disposed, and a connecting rod between the first thermal driving beam and the second thermal driving beam, wherein first ends of the first thermal driving beam and the second thermal driving beam are connected to the frame, and second ends of the first thermal driving beam and the second thermal driving beam are connected to the connecting beam.
In one or more embodiments of the present invention, an included angle is formed between the first thermal driving beam and the second thermal driving beam, and the included angle is 165 ° to 175 °; and/or the number of the groups of groups,
The first heat driving beams and the second heat driving beams are equal in number and are all provided with a plurality of heat driving beams, and the plurality of first heat driving beams and the plurality of second heat driving beams are connected in series through wires;
the first thermal driving beam and/or the second thermal driving beam and/or the connecting rod are/is made of Cu, W, niCr alloy, heavily doped n-type Si or Al.
In one or more embodiments of the present invention, the connection beam is arranged in a detour manner, and the connection beam includes a plurality of first detour sections and a plurality of second detour sections, wherein the length direction of the first detour sections is parallel to the symmetry axis direction of the thermal driving unit, and the length direction of the second detour sections is perpendicular to the symmetry axis direction of the thermal driving unit.
The technical scheme provided by the other specific embodiment of the invention is as follows:
An optical cross-connect comprising an input optical fiber, a first MEMS optical switch, a second MEMS optical switch, and an output optical fiber, all of which are as described above, disposed in that order.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides an MEMS optical switch and an optical cross connector, which combine the front super-structure surface technology with the optical switch technology, and utilize the super-structure surface lens to realize the collimation and deflection functions of an optical path, so that the optical performance is superior to that of the traditional lens, and more importantly, the optical function design of the super-structure surface lens is more flexible, and the super-structure surface lens has great potential and expansion space in the field of optical communication;
The coupling driving mode adopted by the invention combines electromagnetic driving with thermal driving, overcomes the defect of low response speed of the thermal driving by utilizing the fast response speed of the electromagnetic driving, and simultaneously has large current density in the thermal driving unit when generating joule heat, so that the contribution of lorentz force to output displacement is considerable, and the function of accurate alignment can be provided on the basis of large output displacement.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to the drawings without inventive effort to those skilled in the art.
FIG. 1 is a schematic diagram of a MEMS optical switch according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a super-structured surface lens according to an embodiment of the present invention;
FIG. 3 is a graph showing the relationship between the size and the phase of the super-structured surface lens and the transmittance according to an embodiment of the present invention;
FIG. 4 is an enlarged view of a partial structure at A in FIG. 1;
FIG. 5 is a schematic diagram of a MEMS optical switch thermally and electromagnetically driven according to an embodiment of the present invention;
FIG. 6 is an enlarged view of a part of the structure at B in FIG. 1;
FIG. 7 is a schematic side view of a MEMS optical switch according to an embodiment of the invention;
FIG. 8 is a schematic diagram of an optical cross-connect in accordance with another embodiment of the present invention;
FIG. 9 is a graph of results of an OXC simulation of a super-structured surface lens beam deflection to achieve 49 output ports in another embodiment of the invention;
FIG. 10 is a graph showing the results of simulation of beam deflection intensity distribution of an ultra-structured surface lens according to another embodiment of the present invention.
Detailed Description
In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.
The technical scheme of the invention will be described below with reference to the accompanying drawings.
Referring to fig. 1 and 2, in an embodiment of the present invention, a MEMS optical switch includes a frame 1 and an ultra-structured surface lens 2 located in the frame 1, where the ultra-structured surface lens 2 is used to adjust a phase; the super-structured surface lens 2 is connected with the frame 1 through a plurality of groups of connecting structures 3 which are oppositely arranged; the super-structured surface lens 2 comprises a substrate 21 and sub-wavelength structural units 22 distributed on the substrate 21 in an array, wherein the sub-wavelength structural units 22 are micro-nano columns with the same height and different sizes.
It should be explained that the optical fiber signal enters the free space and is a divergent light beam, and the communication wavelength of the divergent light beam is 1550nm. After a certain distance of propagation, the divergent light beam is taken as an incident light beam and is incident on the super-structure surface lens 2 of the MEMS optical switch to form a light spot, the coverage area of the light spot comprises a plurality of sub-wavelength structural units 22, and the sizes of the sub-wavelength structural units 22 at different positions are different, so that different phase regulation effects can be formed on the light spot. Wherein the super-structured surface lens 2 is driven by the connection structure 3, thereby obtaining an adjustable position; after the divergent light beam emitted by the optical fiber is transmitted through the super-structure surface lens 2, the output light beam is a collimated light beam, and the propagation direction is deflected and coupled to the target port, so that the light path routing function is realized.
According to the design, the MEMS optical switch in the embodiment can realize the collimation and deflection functions of the optical path through the super-structured surface lens 2, is convenient to regulate and control, reduces elements required by the optical switch device, and reduces the volume of the whole device.
Specifically, the phase distribution of the super-structured surface lens 2 in the present embodiment satisfies the equation:
Where λ is the wavelength of light, f is the focal length of the super-structured surface lens 2, and r is the position of the sub-wavelength structural unit 22 on the super-structured surface lens 2.
Of course, the application is not limited thereto, and the phase distribution of the super-structured surface lens 2 may also satisfy other different equations. Illustratively, the phase distribution of the super-structured surface lens 2 satisfies the equation:
Where λ is the wavelength of the incident beam, f is the focal length of the super-structured surface lens, and r is the position of the sub-wavelength building block on the super-structured surface lens.
Specifically, the correspondence between different sizes of the sub-wavelength structure units 22 and phases and transmittance in the present embodiment is shown in fig. 3. According to the invention, the phase distribution can be determined according to the wavelength of light and the focal length of the super-structured surface lens 2, and then the phase distribution is mapped into the size distribution of the sub-wavelength structural unit 22 according to the corresponding relation, so that the processing layout of the super-structured surface lens 2 is obtained. Wherein the dotted line represents the magnitude of transmittance, and the solid line represents the magnitude of phase. For example, when the equivalent size of the sub-wavelength structure unit 22 is approximately 350nm, the transmittance of the super-structured surface lens 2 covered by the light spot is minimum, and the phase is approximately-0.5 rad, and these sizes should be avoided when selecting the sub-wavelength structure unit 22 due to the smaller transmittance. The phase of light is an alternating waveform change that the photons vibrate when the light wave advances. Since light is an electromagnetic wave, its photon vibration is perpendicular to the magnetic vibration and to the wave propagation direction, resulting in a change in the waveform at the time of propagation. When the same light wave passes through substances having different refractive indexes, the phase of the light changes, and the wavelength and amplitude also change. Thus, the super-structured surface lens 2 processed in this way can meet the demands of collimation and deflection of the light beam of the corresponding light wavelength.
In view of the requirement of the transmittance of the super-structured surface lens 2 for the divergent light beam, quartz is optionally used as the material of the substrate 21 in this embodiment. Such as glass, for example. Alternatively, the material of the sub-wavelength structure unit 22 in this embodiment is one or more of amorphous silicon, single crystal 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 higher transmittance.
To facilitate driving the micromirror in motion to form an adjustable position, conventional driving methods of MEMS optical switches in the prior art include:
1. Electrostatic driving: the applied voltage acts on the micro mirror, and the vibration and the movement of the structure are realized through the electric field force. Voltage driving typically uses an adjustable voltage source or drive circuit that can provide control of the application of different vibration frequencies and amplitudes to the micromirror.
2. Thermal driving: the micromirrors are driven by temperature variations due to thermal effects. For example, the control of the micromirrors is achieved by a combination of materials having different coefficients of thermal expansion or by electrothermal devices.
3. And (3) pressure driving: the micromirror is driven by the pressure of gas or liquid. For example, micro air pumps or micro fluidic systems are used to apply pressure to control and move the micro mirrors.
4. Electromagnetic driving: the applied magnetic field is used to apply force to the micromirror, thereby achieving vibration and motion thereof. Electromagnetic or permanent magnet drives are typically used to provide a steady magnetic field and control the micromirror by changing the direction and magnitude of the magnetic field. In practical application, different MEMS driving modes should be reasonably selected and the micromirror should be designed in combination with the driving target according to different application scenes and in combination with the process conditions.
Referring to fig. 1, the connection structure 3 in this embodiment includes a thermal driving unit 31 connected to the frame 1 and a connection beam 32 connecting the thermal driving unit 31 and the super-structured surface lens 2, the thermal driving unit 31 being disposed in axisymmetric. According to the design, the super-structured surface lens 2 can be driven by a thermal driving mode, and the thermal driving mode has the advantages of large driving displacement, large driving force output, low driving voltage and the like.
Specifically, referring to fig. 4, the thermal driving unit 31 in the present embodiment includes a first thermal driving beam 311 and a second thermal driving beam 312 symmetrically disposed, and a connecting rod 313 between the first thermal driving beam 311 and the second thermal driving beam 312, the first ends of the first thermal driving beam 311 and the second thermal driving beam 312 are connected to the frame 1, and the second ends of the first thermal driving beam 311 and the second thermal driving beam 312 are connected to the connecting beam 32. Wherein the thermal drive unit 31 has a V-shape with the sharp corner pointing towards the super-structured surface lens 2. Referring to fig. 5, in order to realize the thermal driving, it is necessary to apply electric current to the first thermal driving beam 311, the second thermal driving beam 312, and the connection rod 313, and the first thermal driving beam 311 and the second thermal driving beam 312 to which electric current is applied generate joule heat, so that the first thermal driving beam 311 and the second thermal driving beam 312 expand in volume. Since the equivalent stiffness of the V-shaped thermal driving unit 31 perpendicular to the length direction of the connection rod 313 is much smaller than that of the connection rod 313, this small amount of thermal expansion can be converted into displacement in the length direction of the connection rod 313, so that displacement of the super-structured surface lens 2 can be driven by thermal driving.
The basic principle can be expressed as:
Qe＝J·E
ε＝α(T)(T-Tref)
Where Q e is Joule heat, J is current density, E is electric field strength, ε is strain, α is coefficient of thermal expansion, T is thermodynamic temperature, and T ref is initial temperature.
Alternatively, in order to amplify the displacement of the super-structured surface lens 2, referring to fig. 4, the number of the first thermal driving beams 311 and the second thermal driving beams 312 in the present embodiment is equal and a plurality of the first thermal driving beams 311 and the second thermal driving beams 312 are all provided, and the plurality of the first thermal driving beams 311 and the plurality of the second thermal driving beams 312 are connected in series by wires. With this design, when the heat drive unit 31 is energized, more thermal expansion amount can be generated, so that the displacement amount in the length direction of the connection rod 313 can be made larger.
Since the included angle between the first thermal driving beam 311 and the second thermal driving beam is an important design parameter, the larger the included angle is, the larger the output driving force is, the included angle is reduced, and although the driving force is reduced, the output displacement is significantly increased, so that, optionally, the first thermal driving beam 311 and the second thermal driving beam 312 in this embodiment are symmetrically arranged along the length direction of the connecting rod 313, and the included angle between the first thermal driving beam 311 and the second thermal driving beam is 170 °. Of course, the included angle may be 165 °, or 175 °, or 165 ° to 175 °.
Optionally, due to requirements on electrical resistance and thermal expansion coefficient, at least one of the first thermal driving beam 311, the second thermal driving beam 312, and the connecting rod 313 in the present embodiment is made of one or more of Cu, W, niCr alloy, heavily doped n-type Si, and Al. These materials have a high electrical conductivity and a high coefficient of thermal expansion.
Referring to fig. 5, the outer edge of the outer frame of the MEMS optical switch in the present embodiment is substantially square, and 4 thermal driving units 31 are provided, and the super-structured surface lens 2 is connected to the frame 1 through 2 thermal driving units 31 provided in the horizontal axis direction and 2 thermal driving units 31 provided in the vertical axis direction, respectively. Thus, the thermal driving unit 31 can provide displacement adjustment of the super-structured surface lens 2 in 4 directions of up, down, left, and right.
Alternatively, referring to fig. 6, the connection beam 32 in the present embodiment is disposed in a detour manner, and the connection beam 32 includes a plurality of first detour sections 321 and a plurality of second detour sections 322, where the length direction of the first detour sections 321 is parallel to the symmetry axis direction of the thermal driving unit 31, and the length direction of the second detour sections 322 is perpendicular to the symmetry axis direction of the thermal driving unit 31. Wherein the connecting beam 32 has a circuitous structure. With this design, the thermal driving unit 31 and the super-structured surface lens 2 can be connected by the connection beam 32, so that the rigidity in the length direction of the connection beam 32 is large and the rigidity in the width direction of the connection beam 32 is small. When one of the thermal driving units 31 is charged with current, the thermal driving unit 31 expands in volume, so that larger output displacement can be generated in the length direction of the connecting beam 32, and because the other thermal driving units 31 are not charged with current, the other thermal driving units cannot generate larger damping, the output displacement is influenced, and further, the movement adjustment in the length direction of the connecting beam 32 connected with the thermal driving unit 31 charged with current in the same frame 1 is realized. It will be appreciated that when current is applied to a plurality of thermal drive units 31, independent motion adjustment of multiple degrees of freedom under the same frame 1 can be achieved.
Preferably, referring to fig. 7 in combination with fig. 5, the MEMS optical switch in the present embodiment further includes the permanent magnet 4 located under the thermal driving unit 31 because of the slow thermal driving response speed and high power consumption, which is difficult to control at the time of precise regulation. By adding the permanent magnet 4 to generate the lorentz force in the energized conductor, the lorentz force response is quick and easy to regulate, so that the precise alignment of the micromirror is easy to realize. In view of the large current intensity in the thermal driving unit 31, the permanent magnet 4 is placed right below the thermal driving unit 31, so that the thermal driving unit 31 generates large lorentz force, and the quick-response lorentz force is utilized to provide an original driving force for thermal driving, so that the defect of low thermal driving response speed is overcome; in addition, the lorentz force may also provide an important function of fine tuning when aligning the fiber optic signals.
The basic principle can be expressed as:
|F|＝|IL×B|＝BIL·sinθ
wherein F is Lorentz force, I is current intensity, L is conductor length, B is magnetic induction intensity, and θ is the included angle between the conductor and the direction of the magnetic induction intensity.
When a voltage is applied to both ends of the thermal driving unit 31, a lorentz force parallel to the direction of the connecting rod 313 is first generated by a large current density, the temperature of the thermal driving unit 31 rises rapidly with the generation of joule heat, and since both ends of the thermal driving unit 31 are connected to the frame 1, the thermal expansion amount of the thermal driving unit 31 can only be released in the direction of the middle connecting rod 313, and since both the first thermal driving beam 311 and the second thermal driving beam 312 have an included angle with the connecting rod 313, this thermal expansion amount will be converted into an output displacement in the length direction of the connecting rod 313, and the output displacement is converted into an in-plane translational motion of the super-structured surface lens 2 through the connected circuitous connecting beam 32.
In order to be able to apply the resulting lorentz magnetic force on the thermal drive unit 31, the short axis direction of the permanent magnet 4 in the present embodiment is parallel to the symmetry axis direction of the thermal drive unit 31. With this design, the thermal expansion direction of the thermal driving unit 31 is the same as the direction of the lorentz magnetic force, which is more favorable for realizing the precise adjustment of the super-structured surface lens 2.
Referring to fig. 8, an optical cross-connect according to another embodiment 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 drawings) sequentially arranged. Wherein the first MEMS optical switch 101 and the second MEMS optical switch 102 are both as in the embodiments described above. The optical cross-connect in one embodiment comprises 49 ports, each having an input optical fiber 5, a first MEMS optical switch 101, a second MEMS optical switch 102, and an output optical fiber arranged in sequence. As shown in fig. 9, each circular spot in the figure represents the result of an output beam when the super-structured surface lens 2 is brought to a specific position with a specific displacement of the super-structured surface lens 2. The intensity distribution curves of the plurality of output light beams obtained by the plurality of super-structured surface lenses 2 are shown in fig. 10, in which each peak represents the intensity distribution of the corresponding output light beam on the second MEMS optical switch 102, and the intensity distribution curves are gaussian. The result shows that the ultra-structured surface lens 2 can simultaneously replace the functions of a collimating lens and a reflecting mirror in the traditional optical switch, has the characteristics of replacing or even exceeding the deflection angle and the light weight which can be provided by the traditional optical lens, integrates the functions of collimation and light path deflection of optical signals, and effectively reduces the complexity of the traditional optical switch system.
The technical scheme shows that the invention has the following beneficial effects:
the invention provides an MEMS optical switch and an optical cross connector, which combine the front super-structure surface technology with the optical switch technology, and utilize the super-structure surface lens to realize the collimation and deflection functions of an optical path, so that the optical performance is superior to that of the traditional lens, and more importantly, the optical function design of the super-structure surface lens is more flexible, and the super-structure surface lens has great potential and expansion space in the field of optical communication;
The coupling driving mode adopted by the invention combines electromagnetic driving with thermal driving, overcomes the defect of low response speed of the thermal driving by utilizing the fast response speed of the electromagnetic driving, and simultaneously has large current density in the thermal driving unit when generating joule heat, so that the contribution of lorentz force to output displacement is considerable, and the function of accurate alignment can be provided on the basis of large output displacement.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.
Claims (11)
1. A MEMS optical switch comprising a frame and a super-structured surface lens within the frame, the super-structured surface lens for adjusting phase; the super-structured surface lens is connected with the frame through a plurality of groups of connecting structures which are oppositely arranged; the super-structured surface lens comprises a substrate and sub-wavelength structural units distributed on the substrate in an array mode, wherein the sub-wavelength structural units comprise a plurality of micro-nano columns with the same height and different sizes, and the super-structured surface lens is used for collimating and deflecting incident light beams incident on the super-structured surface lens to transmit the incident light beams to a target port.
2. The MEMS optical switch of claim 1, wherein the phase profile of the super-structured surface lens is determined by at least three parameters, namely, a wavelength of the incident beam, a focal length of the super-structured surface lens, and a location of the sub-wavelength structural unit on the super-structured surface lens.
3. The MEMS optical switch of claim 2, wherein the phase profile of the super-structured surface lens satisfies the equation:
Where λ is the wavelength of the incident beam, f is the focal length of the super-structured surface lens, and r is the position of the sub-wavelength structural unit on the super-structured surface lens; and/or the number of the groups of groups,
The phase distribution of the super-structured surface lens satisfies the equation:
Where λ is the wavelength of the incident beam, f is the focal length of the super-structured surface lens, and r is the position of the sub-wavelength building block on the super-structured surface lens.
4. The MEMS optical switch of claim 1, wherein the substrate is quartz; and/or the number of the groups of groups,
The material of the sub-wavelength structural unit adopts one or more of amorphous silicon, monocrystalline silicon, polycrystalline silicon, titanium dioxide, silicon nitride and gallium nitride.
5. The MEMS optical switch of claim 1, wherein the connection structure comprises a thermal drive unit coupled to the frame and a connection beam coupling the thermal drive unit and the super-structured surface lens, the thermal drive unit being disposed axisymmetrically.
6. The MEMS optical switch of claim 5, further comprising a permanent magnet positioned below the thermal drive unit.
7. The MEMS optical switch of claim 6, wherein the short axis direction of the permanent magnet is parallel to the symmetry axis direction of the thermal drive unit.
8. The MEMS optical switch of claim 5, wherein the thermal drive unit comprises first and second thermal drive beams disposed symmetrically, and a connecting rod between the first and second thermal drive beams, first ends of the first and second thermal drive beams each being connected to the frame, and second ends of the first and second thermal drive beams each being connected to the connecting beam.
9. The MEMS optical switch of claim 8, wherein the first thermal drive beam and the second thermal drive form an included angle therebetween, the included angle being 165 ° -175 °; and/or the number of the groups of groups,
The first heat driving beams and the second heat driving beams are equal in number and are all provided with a plurality of heat driving beams, and the plurality of first heat driving beams and the plurality of second heat driving beams are connected in series through wires;
the first thermal driving beam and/or the second thermal driving beam and/or the connecting rod are/is made of Cu, W, niCr alloy, heavily doped n-type Si or Al.
10. The MEMS optical switch of claim 5, wherein the connection beam is a circuitous arrangement, the connection beam comprises a plurality of first circuitous segments and a plurality of second circuitous segments, the length direction of the first circuitous segments is parallel to the symmetry axis direction of the thermal drive unit, and the length direction of the second circuitous segments is perpendicular to the symmetry axis direction of the thermal drive unit.
11. An optical cross-connect comprising an input optical fiber, a first MEMS optical switch, a second MEMS optical switch, and an output optical fiber disposed in sequence, wherein the first MEMS optical switch and the second MEMS optical switch are as defined in any one of claims 1-10.
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| CN202410229955.8A CN117891062A (en) | 2024-02-29 | 2024-02-29 | MEMS optical switch and optical cross-connect |
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| CN202410229955.8A CN117891062A (en) | 2024-02-29 | 2024-02-29 | MEMS optical switch and optical cross-connect |
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| CN117891062A true CN117891062A (en) | 2024-04-16 |
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