WO2019084710A1

WO2019084710A1 - Multi-stage mems optical switch unit and optical cross device

Info

Publication number: WO2019084710A1
Application number: PCT/CN2017/108273
Authority: WO
Inventors: 闫云飞; 赵晗; 冯志勇; 邹冰
Original assignee: 华为技术有限公司
Priority date: 2017-10-30
Filing date: 2017-10-30
Publication date: 2019-05-09
Also published as: CN111247472A; CN114815076A; CN111247472B

Abstract

Disclosed are a multi-stage MEMS optical switch unit and an optical cross device. In the multi-stage MEMS optical switch unit, a movable connection is established between a micro-mirror and a base by means of a cantilever beam. The cantilever beam is used to maintain the micro-mirror in an initial state when none of N electrodes generates an acting force, and to make the micro-mirror be in a target deflection state when at least one of the N electrodes generates the acting force, and to make the micro-mirror resume the initial state when the active force is zero. A cavity space is formed between the micro-mirror and the base, the N electrodes and M stoppers are all arranged in the cavity space, and the N electrodes and the M stoppers are fixed to the base. At least one of the N electrodes is used to generate the acting force to control the micro-mirror so that same enters the deflection state. The micro-mirror is used so that same enters the deflection state under the acting force from at least one of the N electrodes, and at least one of the M stoppers is used to stop the micro-mirror, such that the micro-mirror is stopped in the target deflection state.

Description

Multi-level MEMS optical switch unit and optical cross device

Technical field

The embodiments of the present application relate to the field of optical communications, and in particular, to a micro-electro-mechanical system (MEMS) optical switch unit and an optical cross-device.

Background technique

In recent years, with the development of optical switching technology and the application of wavelength division multiplexing (WDM), the capacity of optical network node equipment is getting larger and larger, which puts higher requirements on the survivability of the network. Optical Cross-connect (OXC) integrates transmission and switching. It has large transmission capacity, flexible networking, scalable and reconfigurable network, easy upgrade, and transparent transmission of different speed levels in various formats. The signal can meet the many advantages of the user signal type and the growing demand of the service type, and is an important node device that constitutes an Optical Transport Network (OTN).

The key to the realization of OXC is the development and application of advanced optical devices. Among them, there are mechanical optical switches, polymer switches, semiconductor optical switches, Planar Lightwave Circuits (PLCs) and MEMS in optical switches. Especially for MEMS optical switches, technology is developing rapidly. OXC optical switches are developing in the direction of low loss, high isolation, flexible dynamics, low power consumption, small size and low cost.

At present, most of the mature commercialization is OXC based on MEMS technology. The OXC optical switch matrix is fabricated by using a micro-motion micro-mirror, and the micro-motion micro-mirror can adopt the up-and-down folding mode, the left-right movement mode or the rotation mode to realize the on/off function of the optical switch. The optical switch made by MEMS technology integrates mechanical structure, micro-actuator and micro-mirror on the same substrate, and is compact, lightweight and easy to expand. MEMS optical switches may include two-dimensional (2 Dimensional, 2D) and three-dimensional (3 Dimensional, 3D) MEMS optical switches. Among them, the 2D MEMS optical switch is a digital structure, and the 3D MEMS optical switch is an analog structure.

In a 2D MEMS optical switch, all of the micromirrors and the input and output fibers are on the same plane, and the micromirrors are upright and inverted by electrostatic actuators or the micromirrors are placed in the optical path in a "warp" manner. The function of the pop-up optical path is to realize the functions of "on" and "off", so the 2D structure is also called digital type.

An N×N 2D optical switch requires N ² micro mirrors. The advantage of the 2D structure is that the control is simple. The disadvantage is that the number of switching ports cannot be made large due to the limitation of the optical path and the area of the micro mirror. In the 3D structure, all the micromirrors are on opposite planes, and the switching of the optical paths is achieved by changing the different positions of each micromirror.

An N×N 3D optical switch requires only 2N micromirrors, but each micromirror requires at least N precisely controllable movable positions, so the 3D structure is also called analog. Contrary to the 2D structure, the advantage of the 3D structure is that the number of switch ports can be made large, and the exchange capacity of thousands of ports can be realized.

In the large-scale OXC, the 3D MEMS structure is mainly applied, and the 3D MEMS is a state in which the simulated micromirror is switched to a floating state, and there is a problem that the switching oscillation time is long and the switching speed is slow, for example, switching of the 3D analog MEMS. When the micromirror is controlled to deflect to the design position, the micromirror is finally suspended, so the micromirror needs a certain time of oscillation to reach a stable state. The oscillation time of the micromirror is generally greater than 10 milliseconds (millisecond, ms), limited by the oscillation time of the micromirror, and the switching speed of the micromirror is generally on the order of 10 ms or 100 ms. Seriously affects the state switching time of the micro mirror, resulting in OXC cutting based on 3D analog MEMS The speed limit is limited by the switching speed of the MEMS.

In addition, the MEMS structure provided by the prior art is an analog MEMS, and the control mechanism and the driving structure are quite complicated. The working mode is analog, so the control circuit needs to accurately control the voltage applied to the electrode to control the micro mirror. The deflection state, the control part is complicated, and the cost is high.

Summary of the invention

The embodiment of the present application provides a multi-level MEMS optical switch unit and an optical crossover device, which can implement a multi-level digital optical switching engine, and simplify the deflection state control of the micro control mirror.

In a first aspect, the embodiment of the present application provides a multi-level MEMS optical switch unit, including: a micro mirror, a substrate, a cantilever beam, N electrodes, and M blockers, wherein the N and M are greater than or equal to 2. a positive integer, wherein the micromirror is movably connected to the substrate by the cantilever beam; the cantilever beam is configured to cause the micromirror when no force is generated by the N electrodes Maintaining an initial state; causing the micromirror to be in a target deflection state when at least one of the N electrodes generates a force; and returning the micromirror to an initial state when the force is zero; A cavity space is formed between the micromirror and the substrate, and the N electrodes and the M stoppers are disposed in the cavity space, the N electrodes and the M stoppers Fixed to the substrate; at least one of the N electrodes for generating a force to control the micromirror to enter a deflected state; the micromirror for at least one of the N electrodes An electrode enters a deflected state under the force of the electrode; Said M is at least one stopper is a stopper for blocking the micro mirror, so that the micro mirror to the target yaw stopped state.

In the embodiment of the present application, the multi-level MEMS optical switch unit may include: a micro mirror, a base, a cantilever beam, N electrodes, and M stoppers, and the micro mirror is connected to the base through the cantilever beam; the cantilever beam, The micromirror is kept in an initial state when no force is generated on the N electrodes; the micromirror is in a target deflection state when the force generated by the electrode; and the micromirror is restored to an initial state when the force is zero A cavity space is formed between the micro mirror and the substrate, N electrodes and M stoppers are disposed in the cavity space, N electrodes and M stoppers are fixed on the substrate; electrodes are used for generating force and controlling The micromirror enters a deflected state; a micromirror for entering a deflected state under the force of the electrode; and a stopper for blocking the micromirror to stop the micromirror to a target deflected state. In the embodiment of the present application, the force can be generated by the multiple electrodes to control the micro-mirror in the target deflection state. Therefore, the embodiment of the present application can implement a multi-level digital optical switching engine, and the multi-level MEMS optical switch unit structure has many The blocker shortens the oscillation time when the micromirror is switched, and has a high-speed switching speed. As a digital chip, the switching speed is much faster than that of the analog MEMS chip, and the control circuit of the digital chip is simpler, and the system debugging and assembly is more convenient. Since the multi-level MEMS optical switch unit has a plurality of control electrodes and blocking columns, the micro-mirrors have a plurality of deflection states, and the OXC of the large ports is easily realized.

In a possible design of the first aspect of the present application, the cantilever beam is specifically configured to maintain the micromirror in an initial state when no voltage is applied to the N electrodes; at least the N electrodes When an electrode generates an electrostatic force, the micromirror is in a target deflection state; when the electrostatic force is zero, the micromirror is restored to an initial state; at least one of the N electrodes is specifically used An electrostatic force is generated on the micromirror after application of a voltage. At least one of the N electrodes in the embodiment of the present application can apply a voltage to generate an electrostatic force to the micromirror, and the micromirror can be deflected by the electrostatic force.

In a possible design of the first aspect of the present application, the multi-level MEMS optical switch unit further includes: N silicon pass a hole and electrode control circuit, wherein the N electrodes are respectively connected to the electrode control circuit through the N through silicon vias; the electrode control circuit is configured to control at least one of the N electrodes Produce force. The electrode can be connected to the solder joint on the other side of the substrate through the through silicon via, and the electrode control circuit is connected to the electrode through the solder joint, and the electrode control circuit can control the voltage on the N electrodes through the through silicon via.

In a possible design of the first aspect of the present application, the N and the M are equal, and the N electrodes are in one-to-one correspondence with the M stoppers; the N electrodes are evenly distributed on the substrate And the M blockers are evenly distributed on the substrate; when the i-th electrode generates a force, the i-th blocker provides a barrier to the micro-mirror, so that the micro-mirror stops at the target deflection state The i is a positive integer less than or equal to the N. The number M of the blockers may be equal to the number N of the electrodes. For example, each blocker may be correspondingly provided with a blocker. For example, an i-th blocker may be disposed around the i-th electrode, and the i-th blocker may be used for The blocking of the micromirror when the i-th electrode generates an electrostatic force shortens the oscillation time when the micromirror is switched. The processing difficulty of the multi-level MEMS optical switch unit can be simplified by the one-to-one correspondence relationship between the electrodes and the stopper.

In a possible design of the first aspect of the present application, when the substrate has a circular structure, the N electrodes are evenly distributed around a central position of the circular structure, and two adjacent ones of the N electrodes The angle between them is equal to 360 ° / N. The angle between two adjacent ones of the N electrodes is equal to 360°/N, and the electrodes are evenly distributed around the center of the circular structure, thereby facilitating the direction of action of the electrostatic force of the control electrode on the micromirror.

In a possible design of the first aspect of the application, the micromirror comprises: a circular reflective lens.

In a possible design of the first aspect of the present application, the number of the cantilever beams is K, the K is a positive integer, and the K is smaller than the N; the M is greater than the N. The number of cantilever beams needs to take into account the number of deflection directions of the micromirrors and the switching speed and accuracy requirements. It will be appreciated that if M is greater than N, the micromirror deflection can be blocked simultaneously by at least two blockers.

In a second aspect, an embodiment of the present application provides an optical crossover device, the optical crossover device comprising: a multi-level MEMS switch array, the multi-level MEMS switch array comprising: any one of the foregoing first aspects Multi-level MEMS optical switch unit. In the embodiment of the present application, the force can be generated by the multiple electrodes to control the micro-mirror in the target deflection state. Therefore, the embodiment of the present application can implement a multi-level digital optical switching engine, and the multi-level MEMS optical switch unit structure has many The blocker shortens the oscillation time when the micromirror is switched, and has a high-speed switching speed. As a digital chip, the switching speed is much faster than that of the analog MEMS chip, and the control circuit of the digital chip is simpler, and the system debugging and assembly is more convenient. Since the multi-level MEMS optical switch unit has a plurality of control electrodes and blocking columns, the micro-mirrors have a plurality of deflection states, and the OXC of the large ports is easily realized.

In a possible design of the second aspect of the present application, the multi-level MEMS switch array is specifically a first multi-level MEMS switch array, or a second multi-stage MEMS switch array; the optical crossover device further includes: an input fiber An array, an input collimator array, a lens, an output collimator array, and an output fiber array, wherein the input fiber array is for beam coupled input; the input collimator array is for The light beam outputted from the input end fiber array is collimated; the first multi-level MEMS switch array includes S first multi-level MEMS optical switch units, and the first multi-stage MEMS optical switch unit is as described above The multi-level MEMS optical switch unit of any one of the aspects, wherein S is a positive integer; the first multi-level MEMS switch array is configured to map a light beam output by the input collimator array through the lens To the second multi-level MEMS switch array; the second multi-level MEMS switch array includes T second multi-level MEMS optical switch units, and the second multi-stage MEMS optical switch unit is as in the first aspect A multi-level MEMS light turn off a unit, the T is a positive integer; the second multi-level MEMS switch array is configured to output a light beam from the first multi-stage MEMS optical switch array to the output collimator array; the output end a collimator array for collimating a beam output from the second multi-stage MEMS switch array; the output fiber array for beam coupling output. Fast and non-destructive switching of the optical signal can be achieved by the aforementioned optical crossover device.

In a possible design of the second aspect of the present application, the input end fiber array includes: S input ports, and each input port position layout has a one-to-one correspondence with a mapping position of the first multi-stage MEMS optical switch unit; The output end fiber array includes: T output ports, wherein each output port position layout has a one-to-one correspondence with a mapping position of the second multi-stage MEMS optical switch unit; each of the first multi-level MEMS light The switching unit can switch the beam to the T directions, the arrangement manner of the first multi-stage MEMS optical switch unit is determined by the switching direction and the switching angle of the second multi-stage MEMS optical switching unit, and the focal length of the lens; The second multi-stage MEMS optical switch unit can switch the beam to the S directions, and the arrangement manner of the second multi-stage MEMS optical switch unit passes the switching direction and the switching angle of the first multi-stage MEMS optical switch unit, and The lens focal length is determined.

In one possible design of the second aspect of the application, the S is equal to the T. The number of input ports and output ports in the input fiber array is equal, and the number of the first multi-stage MEMS optical switch units included in the first multi-stage MEMS switch array is also equal to the second number included in the second multi-stage MEMS switch array. Class MEMS optical switch unit. Unlimited, the number of input ports can also be different from the number of output ports.

In a possible design of the second aspect of the present application, the arrangement of the multi-level MEMS optical switch unit on the multi-level MEMS switch array is annular. The N multi-level MEMS optical switch units on the multi-level MEMS switch array are annularly distributed, and the N multi-level MEMS optical switch units share N micro-mirrors.

In a possible design of the second aspect of the present application, when the current multi-level MEMS optical switch unit in the multi-level MEMS switch array is switched to the target multi-stage MEMS optical switch unit, the beam switching adopts a linear switching path or a broken line switching path. Or arc to switch paths. The switching speed of the optical signal can be improved by different switching switching adopted by the multi-level MEMS switch array.

In a possible design of the second aspect of the present application, the fold line switching path comprises: a two-step linear switching path, the two-step linear switching path passing through a center point position of the multi-stage MEMS switch array. The multi-level MEMS switch array adopts a folding line switching path through the center point position, and the optical signal switching can be completed by two-step linear switching. Compared with the prior art, the number of optical switching paths is reduced, and the efficiency of optical path switching can be improved.

DRAWINGS

1 is a schematic top plan view of a multi-level MEMS optical switch unit according to an embodiment of the present application;

FIG. 2 is a schematic side view showing the structure of a multi-level MEMS optical switch unit according to an embodiment of the present application; FIG.

3 is a schematic diagram of an electrode blocked by a stopper according to an embodiment of the present application;

4 is a schematic structural diagram of a structure of an optical cross device according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another structure of an optical cross device according to an embodiment of the present disclosure;

6 is a schematic diagram of a layout manner of a multi-level MEMS optical switch unit in an optical cross device according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of another layout manner of a multi-level MEMS optical switch unit in an optical cross device according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a beam switching path in an optical cross device according to an embodiment of the present application; FIG.

FIG. 9 is a schematic diagram of another beam switching path in an optical cross device according to an embodiment of the present application; FIG.

FIG. 10 is a schematic diagram of another beam switching path in an optical cross device according to an embodiment of the present application.

Detailed ways

Embodiments of the present application will be described below with reference to the accompanying drawings.

The terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a particular order or order. It is to be understood that the terms so used are interchangeable under appropriate circumstances, and are merely illustrative of the manner in which the objects of the same attribute are used in the description of the embodiments of the present application. In addition, the terms "comprises" and "comprises" and "comprises", and any variations thereof, are intended to cover a non-exclusive inclusion so that a process, method, system, product, or device comprising a series of units is not necessarily limited to those elements, but may include Other units listed or inherent to these processes, methods, products or equipment.

First, a multi-level MEMS optical switch unit provided by an embodiment of the present application is exemplified, and the multi-level MEMS optical switch unit can be applied to an optical cross device. Referring to FIG. 1 and FIG. 2, the multi-level MEMS optical switch unit provided by the embodiment of the present application may include: a micro mirror 101, a substrate 102, a cantilever beam 103, N electrodes 104 (eg, 1041-104N), and M. a blocker 105 (for example, 1051-150M), N and M are positive integers greater than or equal to 2, wherein

The micro mirror 101 is movably connected to the substrate 102 through the cantilever beam 103;

The cantilever beam 103 is configured to maintain the micromirror 101 in an initial state when no force is generated by the N electrodes 104; and to cause the micromirror 101 to be in a target deflection state when the force generated by at least one of the N electrodes 104 is generated. When the force is zero, the micro mirror 101 is restored to an initial state;

A cavity space is formed between the micro mirror 101 and the substrate 102, and N electrodes 104 and M stoppers 105 are disposed in the cavity space, and N electrodes 104 and M stoppers 105 are fixed on the substrate;

At least one of the N electrodes 104 for generating a force to control the micromirror 101 to enter a deflected state;

a micromirror 101 for entering a deflected state under the force of at least one of the N electrodes 104;

At least one of the M blockers 105 blocks the micromirror 101 such that the micromirror stops to a target deflection state.

The movable connection established by the micro mirror 101 and the substrate 102 may also be referred to as a movable connection, that is, the micro mirror 101 and the cantilever beam 103 are connected, the cantilever beam 103 has ductility, and the cantilever beam 103 and the substrate 102 are connected. connection.

It should be noted that, in the embodiment of the present application, one of the N electrodes 104 may generate a force, or two or more adjacent electrodes may simultaneously generate a force, and the micro mirror 101 may be at one electrode. Or the force of a plurality of electrodes enters a deflected state. Similarly, there may be one blocker in the M blockers 105 to block the micro mirrors, or two more blockers at the same time block the micro mirrors at the same time, which is not limited herein.

In some embodiments of the present application, the cantilever beam 103 is configured to maintain the micromirror 101 in an initial state when no voltage is applied to the N electrodes 104; when at least one of the N electrodes 104 generates an electrostatic force, The micro mirror 101 is in a target deflection state; when the electrostatic force is zero, the micro mirror 101 is restored to an initial state;

At least one of the N electrodes 104 is used to generate an electrostatic force to the micromirror 101 after a voltage is applied.

The micromirror 101 is used to enter a deflected state under the action of an electrostatic force. In the embodiment of the present application, both the electrode and the stopper are disposed in a cavity space formed by the micro mirror and the substrate, and the deflection of the micro mirror can be controlled by an electrostatic force generated by at least one of the N electrodes, M At least one of the blockers may be configured to block the deflection of the mirror such that the micro mirror stops to a target deflection state, the number M of the blockers may be equal to the number N of electrodes, or the number M of the blockers is greater than The number of electrodes N is not limited here.

It should be noted that, in the embodiment of the present application, the force generated by the electrode may specifically be an electrostatic force, and the deflection of the micro mirror is controlled by the electrostatic force, and the electrode may also control the deflection of the micro mirror by a thermal driving method, such as an electrode. Thermal energy is generated by application of current, and the cantilever beam is driven by thermal energy to generate torque, and the deflection of the micromirror is controlled by the torque.

In the prior art, the large port OXC uses a 3D analog MEMS chip as an optical switching engine, and the port switching speed is limited by the switching speed of the micro mirror, which makes it difficult to increase the switching speed of the OXC. In the embodiment of the present invention, the electrostatic force is generated by the multi-electrode to control the micro-mirror in the target deflection state. Therefore, the embodiment of the present application can implement a multi-level digital optical switching engine, and the multi-level MEMS optical switch unit has multiple blocking structures. The device (also referred to as a blocking column), in the following embodiments, the barrier and the blocking column are not distinguished, so that the oscillation time when the micro mirror is switched is shortened, and the switching speed is high, and the multi-level MEMS optical switching unit is used as the digital chip. The switching speed is much faster than the analog MEMS chip, and the control circuit of the digital chip is simpler, and the system debugging and assembly is more convenient; the multi-level MEMS optical switch unit has multiple control electrodes and a plurality of blocking columns, so that there are many micro-mirrors A deflection state makes it easy to implement OXC for large ports. The OXC based on the multi-level MEMS optical switch unit has the advantages of fast switching speed, low loss, uncorrelated polarization and large number of ports. The polarization uncorrelated is light for any polarization state, and the multi-level MEMS optical switch unit can perform optical transmission. deal with.

In some embodiments of the present application, as shown in FIG. 2, the substrate 102 and one end surface of the cantilever beam 103 are connected;

The micromirror 101 is connected to the other end surface of the cantilever beam 103, and the two end faces of the cantilever beam 103 are symmetrically arranged.

Wherein, the substrate 102 can provide a movable supporting force of the cantilever beam 103, so that the micro mirror 101 can be movably connected to the substrate 102 through the cantilever beam 103.

In some embodiments of the present application, N and M are equal, and the N electrodes are in one-to-one correspondence with the M stoppers;

N electrodes are evenly distributed on the substrate, and M stoppers are evenly distributed on the substrate;

When the i-th electrode generates a force, the i-th blocker provides a barrier to the micro-mirror such that the micro-mirror stops at a particular deflection state, i being a positive integer less than or equal to N.

Wherein, the number M of the blockers may be equal to the number N of the electrodes. For example, each blocker may be correspondingly provided with a blocker. For example, an i-th blocker may be disposed around the i-th electrode, and the i-th blocker is available. The blocking of the micromirror when the electrostatic force is generated by the i-th electrode shortens the oscillation time when the micromirror is switched. The processing difficulty of the multi-level MEMS optical switch unit can be simplified by the one-to-one correspondence relationship between the electrodes and the stopper.

In some embodiments of the present application, when the substrate has a circular structure, the N electrodes are evenly distributed around the center of the circular structure, and the angle between adjacent two of the N electrodes is equal to 360°/N.

As shown in FIG. 1, the angle between two adjacent ones of the N electrodes is equal to 360°/N, and the electrodes are evenly distributed around the center of the circular structure, thereby facilitating the electrostatic force of the control electrode on the micromirror. direction.

In some embodiments of the present application, as shown in FIG. 2, the multi-level MEMS optical switch unit further includes: N through silicon vias 107 and an electrode control circuit, wherein

N electrodes are respectively connected to the electrode control circuit through N through silicon vias 107;

An electrode control circuit for controlling at least one of the N electrodes to generate a force.

It should be noted that, in FIG. 2, the electrode control circuit is not illustrated, and the electrode may be connected to the solder joint 106 on the other side of the substrate through the through silicon via, and the electrode control circuit is connected to the electrode 104 through the solder joint 106, and the electrode control circuit The voltage across the N electrodes can be controlled through through silicon vias.

In some embodiments of the present application, the micromirror comprises: a circular reflective lens. For example, the micro-mirror may include a circular reflective lens. The reflective lens included in the micro-mirror in the embodiment of the present application may be flexibly configured in an actual scene, which is not limited herein. In other embodiments of the present application, as shown in Figure 2, the micromirror is capable of reflecting the light beam incident on its surface by selecting a suitable reflective film 108 on the mirror.

In some embodiments of the present application, the number of cantilever beams is K, K is a positive integer, and K is less than N; M is greater than N. Among them, the number of cantilever beams needs to comprehensively consider the number of deflection directions of the micromirrors, the switching speed, and the accuracy requirements. It can be understood that if M is greater than N, the deflection of the micromirror can be blocked by at least two blockers at the same time.

In the multi-level MEMS optical switch unit provided by the embodiment of the present application, a structure including a micro mirror, K cantilever beams, N electrodes, M stoppers, etc., can realize N directions of the light beam, and at least one state deflection in each direction Switch. The micromirror is used to reflect the light beam incident on the mirror surface and is connected to the substrate by K cantilever beams. The number of K is a positive integer greater than 4 and less than N. The cantilever beam can connect the micromirror to the substrate in a suspended manner, and has a flexible cantilever beam so that the micromirror can generate N direction deflections upon power-on. The N electrodes are distributed under the micromirrors, and the micromirrors cause N directions to be tilted by power-on. The M blockers are distributed under the micro mirror, which determines the final tilt angle and switching speed after the micro mirror is powered.

Next, the application scenario of the multi-level MEMS optical switch unit is schematically illustrated. Figure 1 shows a single multi-level MEMS optical switch unit, also called a single multi-level digital MEMS lens, for the entire multi-level digital MEMS lens. The structure may include: a mirror 101, a substrate 102, k cantilever beams 103, N electrodes 104, and M stoppers 105. As shown in FIG. 2, the entire multi-stage digital MEMS lens may further include: a solder 106, a through silicon via 107, and a reflective film 108.

In the multi-level MEMS optical switch unit provided by the embodiment of the present application, the mirror has N working states, and the state switching time is less than 1 ms. Therefore, the state switching time of the multi-level MEMS optical switch unit provided by the embodiment of the present application is much smaller than that of the existing one. The switching time of the technology's continuously adjustable MEMS lens structure (approximately 100ms). As shown in Fig. 1, the micromirror structure comprises a circular reflecting mirror, and by selecting a suitable reflecting film on the mirror surface, the micromirror can reflect the light beam incident on the surface thereof. As shown in FIG. 1 and FIG. 2, k cantilever beams are mirror-connected to a substrate, and the lens is spaced apart from the substrate directly below to form a cavity space, which may also be referred to as a space, and the electrodes are not added. In the case of any voltage, the k cantilever beams make the mirror surface stationary parallel to the XY plane. The k cantilever beams have a certain ductility, and the mirror surface can move under the force of the force. The number k of the cantilever beam is greater than 4, less than the number N of the electrodes, and N is the number of rotation directions of the micromirrors. The number of specific electrodes should take into account the number of deflection directions of the lens, the switching speed, and the accuracy requirement. N electrodes are evenly distributed under the lens and on the surface of the substrate, and the angle between each electrode is 360°/N, and 360° means 360 degrees around the circumference. When the electrode is applied with voltage, it will generate an electrostatic force on the mirror surface directly above, giving the lens an electrostatic force extending downward in the Z direction. After the lens is pressed, the tilt will be generated in the Z-axis direction, and the N electrodes pass through the through-silicon via technology and the substrate. The solder joints are connected on one side, and the electrode control circuit is connected to the electrodes in the micromirror structure through these solder joints, and the electrostatic direction of the mirror is controlled by controlling the energization of different electrodes to control the tilt direction of the lens. When the tilt angle of the lens changes, the direction of the reflected beam also changes accordingly. M blocking columns are evenly distributed at the lower end of the lens, as shown in the figure As shown in Fig. 2, when an electrode is energized, the lens is tilted by the electrostatic force in the direction of the electrode, and the lens stops tilting after hitting the blocking column. The mirror state at this time is the corresponding lens state when the electrode is powered.

As shown in FIG. 3, the blocking column determines the tilt state of the lens, and the M blocking columns determine the total number of N deflection directions of the mirror. The height of the blocking column and the distance from the center position determine the angle of tilt when the mirror is deflected. The presence of the blocking column greatly reduces the damping motion time when the lens moves to the final state, increasing the switching speed between the micromirror states. The digitized micromirror shown in FIG. 1 controls the deflection state of the micromirror by controlling the energization state of the electrode under the micromirror structure, thereby controlling the reflection direction of the beam incident on the micromirror, and the reflected beam can be deflected in N directions. Each direction can be deflected by a predetermined angle, and a total of N reflection states can be provided for the same incident beam.

The structure of the multi-level MEMS optical switch unit is exemplified in the foregoing application embodiment, and a new optical path design is performed for the relevant characteristics of the multi-level MEMS optical switch unit, so that it can be applied in the OXC module. At the same time, a multi-stage MEMS optical switch unit can generate multiple deflection states, and the requirements for strict incident delivery requirements are specially designed. Finally, an OXC device based on a multi-level digital MEMS chip-based optical switching engine is formed that is different from the conventional MEMS-based OXC module.

The optical crossover device provided by the embodiment of the present application is schematically illustrated. The optical crossover device includes: a MEMS switch array, and the multi-level MEMS switch array may include: the multi-level MEMS optical switch unit as in the foregoing FIG. 1 to FIG.

In some embodiments of the present application, the multi-level MEMS switch array is specifically a first multi-level MEMS switch array, or a second multi-level MEMS switch array;

As shown in FIG. 4 and FIG. 5, the optical crossover device provided by the embodiment of the present application further includes: an input end fiber array, an input end collimator array, a lens, an output collimator array, and an output end fiber array, wherein

Input fiber array for beam coupled input;

An input collimator array for collimating the beam output from the input fiber array;

The first multi-level MEMS switch array includes S first multi-level MEMS optical switch units, and the first multi-stage MEMS optical switch unit is the multi-stage MEMS optical switch unit shown in FIG. 1 and FIG. 2, and S is a positive integer; a first multi-level MEMS switch array for mapping a beam outputted by the input collimator array through a lens to a second multi-level MEMS switch array;

a second multi-level MEMS switch array comprising T second multi-stage MEMS optical switch units, a second multi-stage MEMS optical switch unit such as the multi-stage MEMS optical switch unit shown in FIG. 1 and FIG. 2, T being a positive integer; a second multi-level MEMS switch array for outputting a beam from the first multi-stage MEMS optical switch array to an output collimator array;

An output collimator array for collimating a beam output from the second multi-stage MEMS switch array;

Output fiber array for beam coupled output.

As shown in FIG. 4 and FIG. 5, the first multi-level MEMS switch array includes a plurality of first multi-level MEMS optical switch units, which is abbreviated as MEMS1 in FIG. 4, and the first multi-level MEMS optical switch unit in FIG. It may also be referred to as a “first multi-level digital MEMS optical switch”. Similarly, the second multi-level MEMS switch array includes a plurality of second multi-level MEMS optical switch units, which is abbreviated as MEMS 2 in FIG. The second multi-level MEMS optical switch unit may also be referred to as a "second multi-stage digital MEMS optical switch."

In some embodiments of the present application, the input fiber array includes: S input ports, and each input port position layout has a one-to-one correspondence with a mapping position of the first multi-level MEMS optical switch unit;

The output end fiber array includes: T output ports, wherein each output port position layout has a one-to-one correspondence with a mapping position of the second multi-stage MEMS optical switch unit;

Each first multi-level MEMS optical switch unit can switch beams to T directions, and the arrangement manner of the first multi-stage MEMS optical switch unit is determined by the switching direction and switching angle of the second multi-stage MEMS optical switch unit, and the focal length of the lens ;

Each of the second multi-stage MEMS optical switch units can switch the beam to the S directions, and the arrangement manner of the second multi-stage MEMS optical switch unit is determined by the switching direction and the switching angle of the first multi-stage MEMS optical switch unit, and the focal length of the lens .

In the embodiment of the present application, the input fiber array and the input collimator array collimate S (positive integer) input beams, and map the beam waist position to the first multi-level MEMS switch array.

The first multi-level MEMS switch array may include S first multi-level MEMS optical switch units (referred to as switch units for short), each switch unit may switch the light beams to T (positive integer) directions, and each direction can switch at least one The angle of the setting; the arrangement of the S switching units is determined by the switching direction and the switching angle of the switching units in the second multi-stage MEMS switch array. The arrangement direction of the S switch units is in one-to-one correspondence with the switching direction of the second multi-stage MEMS switch array.

The first multi-level MEMS switch array and the second multi-level MEMS switch array are respectively located at the front and rear focal planes of the lens, and map the beam waist on the first multi-stage MEMS switch array to the second multi-level MEMS switch array to realize spot change Having any micromirrors on the first multi-level MEMS switch array deflect the same direction and angle, the light beams being mapped to the same location on the second multi-level MEMS switch array, for example to the same location on the second multi-level MEMS switch array Switch unit.

The second multi-level MEMS switch array comprises T second multi-level MEMS optical switch units (referred to as switch units for short); each switch unit can switch the light beams to S (positive integer) directions, and each direction can switch at least one set The angle of arrangement of the T switching units is determined by the switching direction and switching angle of the switching units in the first multi-stage MEMS switch array. The arrangement direction of the T switch units is in one-to-one correspondence with the switching direction of the first multi-stage MEMS switch array.

The output fiber array and the output collimator array collimate T (positive integer) output beams, receive T beams from the second multi-stage MEMS switch array, and couple them out.

In some embodiments of the present application, S is equal to T. That is, the number of input ports and output ports in the input fiber array is equal, and the number of the first multi-stage MEMS optical switch unit included in the first multi-stage MEMS switch array is also equal to the second included in the second multi-stage MEMS switch array. Multi-level MEMS optical switch unit. Unlimited, the number of input ports can also be different from the number of output ports.

In some embodiments of the present application, the arrangement of the multi-level MEMS optical switch units on the multi-level MEMS switch array is annular. As shown in FIG. 6, the N multi-level MEMS optical switch units on the multi-level MEMS switch array are annularly distributed, and the N multi-level MEMS optical switch units share N micro-mirrors. In the figure, there may be N fixed angles for each multi-level MEMS optical switch unit, and the multi-level MEMS optical switch units have different tilt directions for different tilt angles of the multi-level MEMS optical switch units.

Further, in some embodiments of the present application, when the current multi-level MEMS optical switch unit in the multi-level MEMS switch array is switched to the target multi-stage MEMS optical switch unit, the beam switching adopts a linear switching path, or a polygonal line switching path or an arc Shape switching path.

In the embodiment of the present application, the beam switching of the multi-level MEMS optical switch unit may take multiple paths, for example, a linear switching path, a polygonal line switching path, or an arc switching path may be adopted. As shown in Figure 8 to Figure 10, respectively.

Further, in some embodiments of the present application, the fold line switching path includes: a two-step linear switching path, and the two-step linear switching path passes through a center point position of the multi-level MEMS switch array.

Next, please refer to FIG. 7 to FIG. 10 to illustrate a non-destructive switching manner of the multi-level MEMS optical switch unit in the embodiment of the present invention. Taking FIG. 7 as an example, one circle represents a switch unit. Figure 8 shows the line switching road The path shows a broken line switching path, and FIG. 10 shows an arc switching path. In the prior art, the OXC switch needs to switch according to a specific path in order to avoid the influence of the switching beam on the communication port. Switching from an existing port to a target port typically requires 3-5 switching procedures. The switching speed of the OXC switch in the embodiment of the present application is generally 3-5 times of the switching speed of the switching unit. For the circular layout of the optical switch unit, since the switching path does not pass through other ports, switching from any port to the target port requires only one step switching process, that is, the OXC switching speed is shortened to be equal to the switching speed of the switching unit.

The embodiment of the present application further provides a fast lossless switching mode, which is sensitive to crosstalk requirements and non-destructive switching between adjacent ports. The multi-level MEMS switch array employs the annular layout of the previous embodiment. The switch can be switched from the switch port to the switch array center point and then to the target port. The switching speed of the OXC switch is twice the switching speed of the switching unit. Considering the case of simultaneous switching operations of several ports, an arc switching path can also be employed to avoid switching crosstalk between several ports at the same time. At the same time, the switching speed of the OXC switch is increased by less than 2 times the switching speed of the switching unit.

The embodiment of the present application further provides an OXC switch unit arrangement layout manner and a lossless switching manner. The OXC switch unit is arranged in the above-mentioned installation ring or near-ring arrangement, and adopts a pre-switched port to the target port, and the two-step or one-step direct switching mode is adopted, thereby improving the efficiency of the optical path switching.

The embodiment of the present application provides a digital multi-level MEMS optical switch unit, which has both fast and multi-state characteristics. The embodiment of the present application further provides a fast optical switch device. The state, high-speed switching unit can realize a high-speed OXC switching device capable of large port number; the present application proposes a fast lossless optical switch, a switch array layout and a switching mode, which can further improve the switching speed of the existing OXC switching device; The multi-state switch unit, the fast optical switch device and the fast non-destructive switching mode can overcome the dilemma of the existing OXC port number and the switching speed, and realize the large port high speed OXC, which is very helpful for improving the existing network and the cluster optical switching efficiency. .

Next, an optical crossover device implemented based on a multi-level MEMS optical switch unit is illustrated. As shown in FIG. 4 and FIG. 5, it is an SxS optical cross device, which includes: an input fiber array, and an input terminal collimation. Array, first multi-level MEMS switch array (also known as first-stage digital MEMS switch array), lens, second multi-level MEMS switch array (also known as second-stage digital MEMS switch array), output terminal Straight array and output fiber array.

The input end fiber array is used for beam coupling input, and includes S input ports, and each port position layout has a one-to-one correspondence with a mapping position of the first multi-stage MEMS switch array;

The input collimator array includes a plurality of microlens units, the input collimator array is used for collimating the input beams, and each microlens unit is in one-to-one correspondence with the output ports, and the collimator and the optical fiber array are adjusted by The distance, as well as the focal length of the microlens, enables beam collimation. The working distance of the collimator is D1.

The first stage digital MEMS switch array is located at a working distance of the collimating mirror. The mounting angle of the first multi-level MEMS switch array is at an angle to the input beam so that the beams of the input and output switch arrays form an angle of 2 to avoid interference of the optical path. The first multi-level MEMS switch array includes S switching units, each of which can select a particular angle in the S directions. The switch unit has a circular layout with a center radius r, and the position on the ring corresponds to the angular direction of the rotation of the switch unit. The layout radius r satisfies the following formula one:

Where f is the focal length of the lens.

In the optical relay system in which the lens can be formed, the first-stage digital MEMS switch array and the second-stage digital MEMS switch array are respectively located at the focal planes on both sides. By setting the focal length of the lens to achieve spot change, the beam waist radius of the first-stage digital MEMS switch array is ω ₁ , and the beam waist radius at the second-stage digital MEMS switch array is ω ₂ , and ω ₁ and ω ₂ are equal. . The focal length satisfies the following formula 2:

At the same time, the lens can also realize the optical path conversion function. Even if any micromirror on the first-stage digital MEMS switch array deflects the same direction and angle, the light beam is mapped to the switch unit corresponding to the same position on the second-stage digital MEMS switch array.

The first stage digital MEMS switch array comprises: S switch units; each switch unit can switch the beam to S (positive integer) directions, each direction can switch a set angle; S switch arrangement It is determined by the switching direction and switching angle of the switching unit in the first optical array. The switching unit arrangement direction is in one-to-one correspondence with the switching direction of the first multi-level MEMS switch array; the distance between the switching unit and the center point and the switching angle of the first multi-level MEMS switch array satisfy the foregoing formula 1;

Output collimator array and output fiber array: collimate S output beams, receive S beams from the second-stage digital MEMS switch array, and enable high-efficiency coupling output;

Next, an SxT optical cross device provided by an embodiment of the present application is introduced. The device includes: an input fiber array, an input collimator array, a first-stage digital MEMS switch array, a lens, and a second-stage digital MEMS. Switch array, output collimator array, and output fiber array.

The input fiber array includes a two-dimensional fiber array, and the input collimator array includes a two-dimensional collimator array. The S (positive integer) input beams are collimated, the beam waist position is mapped to the first multi-stage MEMS optical switch unit, and the first multi-level MEMS switch array includes S first multi-level MEMS optical switch units.

The first multi-level MEMS switch array comprises: S switch units; each switch unit can switch the beam to M (positive integer) directions, each direction can switch a set angle; the arrangement of the S switch units is The switching direction and switching angle of the switching unit in the second multi-stage MEMS switch array are determined. The switching unit arrangement direction is in one-to-one correspondence with the switching direction of the second multi-level MEMS switch array; the distance between the switching unit and the center point and the switching angle of the second multi-level MEMS switch array satisfy the following formula 3:

Where αj is the deflection angle of the corresponding switching unit in the second multi-stage MEMS switch array.

Lens: the focal length is f, which satisfies the above formula 2; the first multi-level MEMS switch array and the second multi-level MEMS switch array are respectively located at the front and rear of the lens, at the focal plane; the spot conversion function is realized: mapping the first multi-level MEMS switch array The beam is beamed to the second multi-level MEMS switch array; optical path transformation is performed: any micromirrors on the first multi-stage MEMS switch array are deflected in the same direction and angle, and the beam is mapped to the same on the second multi-stage MEMS switch array The switch unit corresponding to the position; the focal length satisfies the following formula four:

The second multi-level MEMS switch array comprises: T switch units; each switch unit can switch the beam to S (positive integer) directions, each direction can switch at least one set angle; the arrangement manner of T switch units By first The switching direction and switching angle of the switching unit in the multi-level MEMS switch array are determined. The switching unit arrangement direction is in one-to-one correspondence with the switching direction of the first multi-level MEMS switch array; the distance between the switching unit and the center point and the switching angle of the first multi-level MEMS switch array satisfy the formula 5:

Where αi is the deflection angle of the first multi-level MEMS switch array with the corresponding switching unit.

Output collimator array and output fiber array: T (positive integer) output beams are collimated, T beams from the second optical switch array are received, and coupled out.

It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should understand that the present application is not limited by the described action sequence. Because certain steps may be performed in other sequences or concurrently in accordance with the present application. In the following, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

In order to facilitate the implementation of the above solution of the embodiments of the present application, related devices for implementing the above solutions are also provided below.

It should be further noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be Physical units can be located in one place or distributed to multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, and specifically may be implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement without any creative effort.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, dedicated hardware, dedicated CPU, dedicated memory, dedicated memory, Special components and so on. In general, functions performed by computer programs can be easily implemented with the corresponding hardware, and the specific hardware structure used to implement the same function can be various, such as analog circuits, digital circuits, or dedicated circuits. Circuits, etc. However, software program implementation is a better implementation for more applications in this application. In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.

Claims

A multi-stage MEMS optical switch unit characterized in that: the multi-stage MEMS optical switch unit comprises: a micro mirror, a substrate, a cantilever beam, N electrodes and M blockers, wherein the N and M are greater than Or a positive integer equal to 2, where

The micromirror is movably connected to the substrate by the cantilever beam;

The cantilever beam is configured to maintain the micromirror in an initial state when no force is generated by the N electrodes; and to cause the micromirror when at least one of the N electrodes generates a force In a target deflection state; when the force is zero, the micromirror is restored to an initial state;

A cavity space is formed between the micromirror and the substrate, the N electrodes and the M stoppers are disposed in the cavity space, the N electrodes and the M blocks Fixing on the substrate;

At least one of the N electrodes is configured to generate a force to control the micromirror to enter a deflected state;

The micromirror for entering a deflected state under the force of at least one of the N electrodes;

At least one of the M blockers is configured to block the micro mirror such that the micro mirror stops to a target deflection state.
The multi-level MEMS optical switch unit according to claim 1, wherein the cantilever beam is specifically configured to maintain the micromirror in an initial state when no voltage is applied to the N electrodes; When at least one of the N electrodes generates an electrostatic force, the micromirror is in a target deflection state; when the electrostatic force is zero, the micromirror is restored to an initial state;

At least one of the N electrodes is specifically configured to generate an electrostatic force to the micromirror after applying a voltage.
The multi-level MEMS optical switch unit according to claim 1, wherein the multi-level MEMS optical switch unit further comprises: N through silicon vias and an electrode control circuit, wherein

The N electrodes are respectively connected to the electrode control circuit through the N through silicon vias;

The electrode control circuit is configured to control at least one of the N electrodes to generate a force.
The multi-level MEMS optical switch unit according to claim 1, wherein the N and the M are equal, and the N electrodes are in one-to-one correspondence with the M blockers;

The N electrodes are evenly distributed on the substrate, and the M stoppers are evenly distributed on the substrate;

When the i-th electrode generates a force, the i-th blocker provides a barrier to the micro-mirror such that the micro-mirror stops at a target deflection state, the i being a positive integer less than or equal to the N .
The multi-level MEMS optical switch unit according to claim 4, wherein when the substrate has a circular structure, the N electrodes are evenly distributed around a center position of the circular structure, the N electrodes The angle between two adjacent electrodes is equal to 360°/N.
The multi-level MEMS optical switch unit of claim 1 wherein said micromirror comprises: a circular reflective lens.
The multi-level MEMS optical switch unit according to claim 1, wherein the number of the cantilever beams is K, the K is a positive integer, and the K is smaller than the N;

The M is greater than the N.
An optical crossover device, comprising: a multi-stage MEMS switch array comprising: multi-level MEMS light according to any one of claims 1 to 7 Switch unit.
The optical crossover device according to claim 8, wherein the multi-level MEMS switch array is specifically a first multi-level MEMS switch array or a second multi-level MEMS switch array;

The optical crossover device further includes: an input fiber array, an input collimator array, a lens, an output collimator array, and an output fiber array, wherein

The input end fiber array is used for beam coupling input;

The input collimator array is configured to collimate a light beam outputted from the input end fiber array;

The first multi-level MEMS switch array includes S first multi-level MEMS optical switch units, and the first multi-level MEMS optical switch unit is the multi-level MEMS optical switch unit according to any one of claims 1 to 7, The S is a positive integer; the first multi-level MEMS switch array is configured to map a light beam output by the input collimator array to the second multi-stage MEMS switch array through the lens;

The second multi-level MEMS switch array includes T second multi-level MEMS optical switch units, and the second multi-stage MEMS optical switch unit is the multi-level MEMS optical switch unit according to any one of claims 1 to 7, The T is a positive integer; the second multi-level MEMS switch array is configured to output a light beam from the first multi-stage MEMS optical switch array to the output collimator array;

The output collimator array is configured to collimate a light beam output from the second multi-stage MEMS switch array;

The output fiber array is used for beam coupling output.
The optical crossover device according to claim 9, wherein the input end fiber array comprises: S input ports, each of the input port position layouts and a mapping position of the first multi-stage MEMS optical switch unit One correspondence

The output end fiber array includes: T output ports, wherein each output port position layout has a one-to-one correspondence with a mapping position of the second multi-stage MEMS optical switch unit;

Each of the first multi-level MEMS optical switch units can switch beams to T directions, and the arrangement manner of the first multi-stage MEMS optical switch units is switched and switched by the second multi-stage MEMS optical switch unit Angle, and lens focal length determination;

Each of the second multi-stage MEMS optical switch units can switch beams to S directions, and the arrangement manner of the second multi-stage MEMS optical switch units is switched and switched by the first multi-stage MEMS optical switch units Angle, as well as lens focal length determination.
The optical crossover device of claim 10 wherein said S is equal to said T.
The optical crossover device according to claim 10, wherein the arrangement of the multi-level MEMS optical switch unit on the multi-level MEMS switch array is annular.
The optical cross-over device according to claim 12, wherein when the current multi-level MEMS optical switch unit in the multi-level MEMS switch array is switched to the target multi-stage MEMS optical switch unit, the beam switching adopts a linear switching path, or Polyline switching path or arc switching path.
The optical crossover device according to claim 13, wherein the fold line switching path comprises: a two-step linear switching path, the two-step linear switching path passing through a center point position of the multi-stage MEMS switch array.