A high-speed MEMS optical phase shifter, its array, packaging structure and optical device

Abstract

The present invention provides a high-speed MEMS optical phase shifter, its array, packaging structure, and optical device. In the phase shifter, fixed drive comb teeth in the second planar region and dynamic drive comb teeth in the first planar region form an electrostatic comb driver; a flat drive electrode in the substrate layer and a vertically moving micromirror in the first planar region form an electrostatic flat driver; a displacement sensor senses the displacement of the vertically moving micromirror and provides closed-loop feedback control of the drive state. In the present invention, a dual drive structure of comb teeth and flat plate drives the vertically moving micromirror in opposite directions, achieving high-speed optical phase shifting with a simple structure. The closed-loop feedback control and dual drive structure simultaneously improve the accuracy of phase shift control. Furthermore, the high-speed phase shifting of the MEMS phase shifter meets the application requirements of high-speed phase shifting with low cost, low power consumption, and a small size. Finally, a displacement sensor integrated within the MEMS chip indicates the phase shift of the MEMS optical phase shifter and provides closed-loop feedback to adjust the drive states of the electrostatic comb driver and electrostatic flat driver, thereby improving the performance of the high-speed phase shifting device.

Description

Technical Field

[0001] The present invention belongs to the field of optical micro-electromechanical technology and optical phased array, and in particular relates to a high-speed MEMS optical phase shifter and its array, packaging structure and optical equipment. Background Art

[0002] Optical phase is a key technical parameter of laser beams, and dynamic control of optical phase is a key technology in laser technology. It has broad application prospects in optical interferometers, interferometric fiber optic sensors, laser beam shaping, laser wavefront correction, and optical phased arrays. Optical phased arrays, a new laser scanning technology developed from microwave phased arrays, extend the operating wavelength of microwave phased arrays to the laser wavelength. They represent a new generation of technology for satellite laser communications. They effectively address a number of technical challenges facing existing satellite laser communication systems, including the large size, single-pointing direction, heavy weight, high moment of inertia, high drive power consumption, and high cost of optical-mechanical scanning antennas. They also address the inability of existing turntable optical-mechanical scanning to meet the requirements of compact, low-cost satellite internet laser communication networks. Chinese researchers have proposed a vector optical phased array solution based on MEMS technology, surpassing existing scalar optical phased array technology. This novel optical phased array system features large array elements, wide scanning angles, and multi-dimensional vector control. Requiring only tens to hundreds of array elements, it is possible to implement a space laser communication system with an equivalent aperture of hundreds of millimeters and a communication range of thousands to tens of thousands of kilometers, demonstrating excellent engineering feasibility. Vector optical phased arrays require high-bandwidth phase control of hundreds of phased array element beams, which creates strong technical demands for high-speed MEMS optical phase shifters and their array devices.

[0003] Optical devices that achieve dynamic optical phase control are called optical phase modulators or optical phase shifters. Their primary function is to manipulate the phase of an optical signal under the control of a control signal. Based on the principle of optical phase control, there are two main mechanisms: optical path control and optical refractive index control. Optical path control achieves optical phase control by controlling the optical path length of the light beam. This is achieved through: 1) Normal movement of an optical mirror. A half-wavelength shift changes the phase of the reflected light by 2π radians. This approach offers significant advantages, including simplicity, efficiency, low optical loss, and polarization insensitivity. However, using a motor to drive the optical mirror has drawbacks such as bulk, high drive power consumption, and slow modulation speed. Using a piezoelectric stack to drive the optical mirror has drawbacks such as bulk, high drive voltage, low modulation speed, poor linearity, and significant hysteresis. 2) Piezoelectric fiber actuators stretch the optical fiber loop to control the phase of the optical signal. This approach offers low optical loss, but suffers from bulk, high drive voltage, low modulation speed, poor linearity, significant hysteresis, and polarization disturbance caused by fiber stretching. Optical refractive index modulation achieves optical phase modulation by controlling the refractive index of the light propagation medium. The technical solutions for this are: 1) Waveguide modulators based on the electro-optic effect, primarily employing LiNbO3 waveguides and electro-optic polymer waveguides. Under the influence of a modulating voltage signal, the refractive index of the waveguide is changed by the electro-optic effect to achieve optical phase modulation. These modulators offer the advantages of extremely high phase modulation speeds, reaching 10 GHz or even higher, low drive voltage, and low power consumption. However, they suffer from high optical loss, polarization sensitivity, and high cost, and are generally only used for high-speed signal modulation in optical communication systems. 2) Waveguide modulators based on the thermo-optic effect, primarily employing thermo-optic modulation with Si waveguides, SiN waveguides, and optical fibers. Thermo-optic modulation with Si and SiN waveguides can achieve modulation bandwidths of up to tens of kHz, but suffers from high modulation power consumption, limited modulation bandwidth, high optical loss, and polarization sensitivity. Optical fiber thermo-optic modulation offers low optical loss and polarization insensitivity, but suffers from low modulation bandwidth, high modulation power consumption, and large size. Therefore, the existing optical phase shifter technology has many shortcomings and is difficult to meet the needs of applications such as vector optical phased arrays, laser beam shaping, and laser wavefront correction.

[0004] With the development of microelectromechanical technology (MEMS, MicroElectro Mechanical Systems), optical MEMS technology that integrates MEMS and optical technology has emerged. This technology integrates MEMS drivers and micro-optical mirrors into a single chip, and has significant technical and cost advantages in the manufacture of MEMS optical phase shifters. The principle of MEMS optical phase shifters is the normal movement of optical mirrors. Its technical advantages are small size, low driving power consumption, low optical loss, polarization insensitivity, and low cost. However, the current technical level is that the optical phase modulation speed is limited by the natural resonant frequency of the MEMS micromirror driving mode, and can only reach a few kHz to tens of kHz. At the same time, the phase shift amount and the phase shift speed are mutually restricted, resulting in the existing MEMS optical phase shifter technology being unable to meet the requirements of high-speed modulation and arraying of MEMS phase shifters for applications such as vector optical phased arrays.

[0005] Therefore, there is an urgent need for a structure or method that can improve the phase shifting speed of a MEMS optical phase shifter.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of this application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are explained in the background technology part of this application. Summary of the Invention

[0007] In view of the above shortcomings of the prior art, an object of the present invention is to provide a high-speed MEMS optical phase shifter and its array, packaging structure and optical device, so as to solve the problem of limited phase shifting speed of MEMS phase shifters in the prior art.

[0008] To achieve the above objectives, the present invention provides a high-speed MEMS optical phase shifter, comprising: a silicon thin film, a substrate layer, and a displacement sensor, wherein the silicon thin film comprises a first planar region and a second planar region, wherein the first planar region, the second planar region, and the substrate layer are all perpendicular to a first direction;

[0009] The first planar area includes a vertical motion micromirror, an elastic beam, a driving comb tooth, and a first peripheral structure layer, wherein the elastic beam is symmetrically distributed with the center of the vertical motion micromirror as the center point, the vertical motion micromirror is elastically connected to the first peripheral structure layer via the elastic beam, and the driving comb tooth is fixedly connected only to the vertical motion micromirror;

[0010] The second planar region includes driving fixed comb teeth and a second peripheral structure layer, the driving fixed comb teeth being fixedly connected to the second peripheral structure layer; the driving fixed comb teeth and the driving movable comb teeth are arranged in an interlaced manner to form an electrostatic comb drive, and the driving direction of the electrostatic comb drive is along the first direction away from the substrate layer;

[0011] The substrate layer includes a flat plate driving electrode and a third peripheral structure layer, the third peripheral structure layer is provided with a groove, and the flat plate driving electrode is fixed to the bottom of the groove; the flat plate driving electrode and the projection of the vertical motion micromirror on the substrate layer have an overlapping portion, and the groove between the flat plate driving electrode and the vertical motion micromirror forms an air gap to form an electrostatic flat plate driver, and the driving direction of the electrostatic flat plate driver is along the first direction toward the substrate layer; the first peripheral structure layer, the second peripheral structure layer, and the third peripheral structure layer are fixedly connected to form an overall structure layer;

[0012] The displacement sensor is used to sense the displacement of the vertically moving micromirror along the first direction. The displacement sensed by the displacement sensor is used to indicate the phase shift of the high-speed MEMS optical phase shifter and to adjust the driving states of the electrostatic comb driver and the electrostatic flat plate driver through closed-loop feedback to control the motion state of the vertically moving micromirror along the first direction.

[0013] Optionally, the displacement sensor includes fixed sensing comb teeth and moving sensing comb teeth, the moving sensing comb teeth are fixedly connected to the vertical motion micromirror, the fixed sensing comb teeth are fixedly connected to the second peripheral structure layer, and the fixed sensing comb teeth and the moving sensing comb teeth are arranged in an interlaced manner to form the displacement sensor.

[0014] Optionally, the displacement sensor includes a ring electrode and the vertical motion micromirror, the ring electrode is fixed to the bottom of the groove and surrounds the flat plate driving electrode, and there is electrical isolation between the ring electrode and the flat plate driving electrode; the ring electrode has an overlapping part with the projection of the vertical motion micromirror and / or the elastic beam on the substrate layer, and the groove between the ring electrode and the vertical motion micromirror and / or the elastic beam forms an air gap to constitute the displacement sensor.

[0015] Optionally, the displacement sensor includes a strain piezoresistor and a reference resistor, the strain piezoresistor is located in the elastic beam, the reference resistor is located in the overall structural layer, the strain piezoresistor and the reference resistor are electrically connected to form a Wheatstone bridge circuit, and the Wheatstone bridge circuit constitutes the displacement sensor.

[0016] Optionally, the output signal bandwidth of the displacement sensor is greater than or equal to 2-10 times the working bandwidth of the high-speed MEMS optical phase shifter.

[0017] Optionally, the displacement sensed by the displacement sensor is used to control the driving states of the electrostatic comb driver and the electrostatic flat plate driver through a PID algorithm closed-loop feedback.

[0018] The present invention also provides a high-speed MEMS optical phase shifter array, which includes n high-speed MEMS optical phase shifters of any one of the above described types arranged in an array, where n is greater than or equal to 2, and two adjacent high-speed MEMS optical phase shifters are electrically insulated.

[0019] Optionally, the n high-speed MEMS optical phase shifters are arranged in a straight line array; or the n high-speed MEMS optical phase shifters are arranged in an a×b square array, where a and b are both integers greater than or equal to 2.

[0020] The present invention further provides a high-speed MEMS optical phase shifter packaging structure, wherein the high-speed MEMS optical phase shifter packaging structure comprises any one of the above-mentioned high-speed MEMS optical phase shifters or / and any one of the above-mentioned high-speed MEMS optical phase shifter arrays;

[0021] The high-speed MEMS optical phase shifter packaging structure also includes an electric drive chip, a sensor detection circuit chip, a feedback control chip, and an input / output connector. The electric drive chip is electrically connected to the electrostatic comb driver and electrostatic plate driver of the high-speed MEMS optical phase shifter to drive the electrostatic comb driver and electrostatic plate driver of the high-speed MEMS optical phase shifter. The sensor detection circuit chip is electrically connected to the displacement sensor of the high-speed MEMS optical phase shifter to process the sensor electrical signal of the displacement sensor. The input / output connector is electrically connected to an external control system to receive a target electrical signal. The feedback control chip is electrically connected to the electric drive chip, the sensor detection circuit chip, and the input / output connector to receive the sensor electrical signal from the sensor detection circuit chip and the target electrical signal received by the input / output connector, and calculates the drive signal required for the vertical motion micromirror to perform vertical displacement, and provides it to the electric drive chip to control the phase shift of the high-speed MEMS optical phase shifter through closed-loop feedback.

[0022] The present invention also provides an optical device, comprising any one of the high-speed MEMS optical phase shifters described above, any one of the high-speed MEMS optical phase shifter arrays described above, and / or a high-speed MEMS optical phase shifter device composed of the high-speed MEMS optical phase shifter packaging structure described above.

[0023] As described above, the high-speed MEMS optical phase shifter, array, packaging structure, and optical device of the present invention have the following beneficial effects:

[0024] The present invention uses an electrostatic comb and an electrostatic plate to form a dual-drive structure to electrostatically drive the vertical motion micromirror in two opposite directions, thereby overcoming the shortcoming of conventional electrostatic drives that only drive in one direction and achieving high-speed optical phase shifting with a simple structure.

[0025] The present invention improves the control accuracy of the phase shift amount of the phase shifter through the cooperation of closed-loop feedback control and dual-drive structure;

[0026] The present invention realizes high-speed optical phase shifting through MEMS optical phase shifters, which is conducive to realizing low-cost, low-power, small-volume high-speed optical phase shifting equipment;

[0027] The present invention integrates a displacement sensor in a MEMS optical phase shifter to further realize a low-cost, low-power, small-volume, high-speed optical phase shifting device, and can provide users with information on the magnitude of the optical phase shift. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It shows a schematic structural diagram of a high-speed MEMS optical phase shifter in Example 1 of the present invention.

[0029] Figure 2 It shows a schematic diagram of the structural layering of the high-speed MEMS optical phase shifter in Example 1 of the present invention.

[0030] Figure 3 It shows a schematic diagram of the structure of the high-speed MEMS optical phase shifter in Example 1 of the present invention after being cut in half.

[0031] Figure 4 It is a schematic structural diagram of the substrate layer in the high-speed MEMS optical phase shifter according to the first embodiment of the present invention.

[0032] Figure 5 Schematic diagram showing a top view of a substrate layer in a high-speed MEMS optical phase shifter according to embodiment 2 of the present invention.

[0033] Figure 6 Shown is a schematic diagram of a partially enlarged top view of a substrate layer in a high-speed MEMS optical phase shifter according to embodiment 2 of the present invention.

[0034] Figure 7 It is a schematic top view of the second plane region of the high-speed MEMS optical phase shifter in embodiment 2 of the present invention.

[0035] Figure 8 It is a side cross-sectional schematic diagram of a high-speed MEMS optical phase shifter in Example 3 of the present invention.

[0036] Figure 9 It shows the electrical connection diagram of the Wheatstone bridge circuit in Example 3 of the present invention.

[0037] Figure 10 It shows a schematic structural diagram of a high-speed MEMS optical phase shifter array in an example of embodiment 4 of the present invention.

[0038] Figure 11 It shows a schematic structural diagram of a high-speed MEMS optical phase shifter array in an example of embodiment 4 of the present invention.

[0039] Figure 12 It shows a schematic structural diagram of the high-speed MEMS optical phase shifter packaging structure in Example 5 of the present invention.

[0040] Component number description

[0041] 100, high-speed MEMS optical phase shifter; 110, first planar region; 111, vertically moving micromirror; 112, elastic beam; 113, first peripheral structure layer; 114, driving comb teeth; 120, second planar region; 121, driving fixed comb teeth; 122, second peripheral structure layer; 130, air gap; 140, substrate layer; 141, planar driving electrode; 142, third peripheral structure layer; 143, groove; 151, sensing fixed comb teeth; 152, sensing comb teeth; 161, ground pad; 162, planar electrode pad; 163, driving comb pad; 164, sensing comb pad; 165, etched insulation groove;

[0042] 251, annular electrode; 252, annular electrode pad; 351, strain gauge varistor; 352, reference resistor; 353, metal lead; 354, resistor pad; 355, input electrical signal; 356, output electrical signal;

[0043] 400, high-speed MEMS optical phase shifter array; 500, high-speed MEMS optical phase shifter chip;

[0044] 600. High-speed MEMS optical phase shifter packaging structure; 601. Upper cover; 602. Package shell; 603. Circuit chip; 604. Input / output connector; 605. Dual-fiber collimator; 606. Package cavity; 607. Electric drive chip; 608. Sensor detection circuit chip; 609. Feedback control chip; 610. PCB board; 611. Flexible cable; 612. Flip-chip solder balls; 613. Thermal adhesive; 614. Bonding wires; 615. Input optical fiber; 616. Output optical fiber; 617. Rod lens C-Lens. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0046] For example, when describing the embodiments of the present invention, schematic diagrams illustrating device structures may be partially enlarged for ease of explanation. These schematic diagrams are merely illustrative and should not limit the scope of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0047] For convenience of description, spatially relative terms such as "under," "below," "below," "below," "above," and "upper" may be used herein to describe the relationship of one element or feature to other elements or features shown in the drawings. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0048] In the context of the present application, a structure described as a first feature being "above" a second feature may include embodiments where the first and second features are in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0049] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0050] It should be noted that the “first direction” mentioned in the present invention can be any direction, and this document only uses the first direction as a reference system to describe the positional relationship between various components.

[0051] Example 1:

[0052] This embodiment provides a high-speed MEMS optical phase shifter 100. Figure 1-Figure 4 As shown, Figure 2 for Figure 1 The structural layer diagram, Figure 3 for Figure 1 Schematic diagram of the structure after cutting in half, Figure 4FIG1 is a schematic structural diagram of a substrate layer 140 in a high-speed MEMS optical phase shifter 100. The high-speed MEMS optical phase shifter 100 includes a silicon thin film, a substrate layer 140, and a displacement sensor. The silicon thin film includes a first planar region 110 and a second planar region 120. The first planar region 110, the second planar region 120, and the substrate layer 140 are all perpendicular to a first direction.

[0053] The first planar area 110 includes a vertical motion micromirror 111, an elastic beam 112, a driving comb tooth 114, and a first peripheral structure layer 113. The elastic beam 112 is symmetrically distributed around the center of the vertical motion micromirror 111. The vertical motion micromirror 111 is elastically connected to the first peripheral structure layer 113 via the elastic beam 112. The driving comb tooth 114 is fixedly connected only to the vertical motion micromirror 111.

[0054] The second planar region 120 includes driving fixed comb teeth 121 and a second peripheral structure layer 122, wherein the driving fixed comb teeth 121 are fixedly connected to the second peripheral structure layer 122; the driving fixed comb teeth 121 and the driving dynamic comb teeth 114 are arranged alternately to form an electrostatic comb drive, and the driving direction of the electrostatic comb drive is along the first direction away from the substrate layer 140;

[0055] The substrate layer 140 includes a flat-plate driving electrode 141 and a third peripheral structure layer 142. The third peripheral structure layer 142 is provided with a groove 143. The flat-plate driving electrode 141 is fixed to the bottom of the groove 143. The flat-plate driving electrode 141 overlaps with the projection of the vertical motion micromirror 111 on the substrate layer 140. The groove 143 between the flat-plate driving electrode 141 and the vertical motion micromirror 111 forms an air gap 130 to form an electrostatic flat-plate driver. The driving direction of the electrostatic flat-plate driver is along the first direction toward the substrate layer 140. The first peripheral structure layer 113, the second peripheral structure layer 122, and the third peripheral structure layer 142 are fixedly connected to form the overall structure layer.

[0056] The displacement sensor is used to sense the displacement of the vertical motion micromirror 111 along the first direction. The displacement sensed by the displacement sensor is used to indicate the phase shift of the high-speed MEMS optical phase shifter 100 and to adjust the driving states of the electrostatic comb driver and the electrostatic flat plate driver through closed-loop feedback to control the motion state of the vertical motion micromirror 111 along the first direction.

[0057] Other optical phase shifter technologies in the existing technology have many shortcomings and are difficult to meet the needs of applications such as vector optical phased arrays, laser beam shaping, and laser wavefront correction. Although MEMS optical phase shifters in the existing technology can overcome many problems of other optical phase shifters, the optical phase modulation speed of MEMS optical phase shifters is limited by the natural resonant frequency of the MEMS micromirror driving mode and can only reach a few kHz to tens of kHz. At the same time, the size of its optical phase shift amount and the phase shift speed are mutually restricted. As a result, the existing MEMS optical phase shifter technology cannot meet the requirements of applications such as vector optical phased arrays for high-speed modulation, large phase shift amount, and arraying of MEMS phase shifters.

[0058] The present invention uses a MEMS process to monolithically integrate an electrostatic plate and a vertical comb dual driver and a displacement sensor. By setting up an electrostatic comb driver and an electrostatic plate driver to form a dual-drive structure for bidirectional high-acceleration vertical drive, the vertical motion micromirror 111 is electrostatically driven in two opposite directions along the first direction respectively, without using an electrostatic driver that can achieve repulsive drive but has a complex structure or significantly increasing the drive voltage, thereby quickly changing the optical path of the incident light wave signal to achieve optical phase shifting; at the same time, by combining closed-loop feedback control with the bidirectional electrostatic drive driving method, the control accuracy of the phase shift amount of the MEMS optical phase shifter can be improved, and high-bandwidth phase shift feedback control can be achieved, breaking through the problem that the working bandwidth of the optical phase shifter is limited by the driving mode of the MEMS driver. The technical difficulties of the mutual constraints between the natural resonant frequency, phase shift amount and phase shift bandwidth meet the requirements of application fields such as vector optical phased array for high-speed, large phase shift amount and arraying of MEMS phase shifters; in addition, since high-speed phase shift can be achieved in MEMS optical phase shifters, it is conducive to the realization of low-cost, low-power, small-volume high-speed optical phase shifting equipment; in addition, by integrating displacement sensors in MEMS optical phase shifters, displacement sensors can be directly prepared in the MEMS structure at the same time, thereby further reducing the preparation time, preparation cost and occupied space required for the additional installation of displacement sensors, further realizing low-cost, low-power, small-volume high-speed optical phase shifting equipment, and promoting the development of technologies such as vector optical phased array, laser beam shaping, and laser wavefront correction.

[0059] Specifically, the first planar area 110 and the second planar area 120 on the silicon film are located on the same silicon film; the vertical displacement generated by pulling down the vertical motion micromirror 111 of the first planar area 110 by the electrostatic flat-plate driver drives the formation of a vertical comb tooth driver with a vertical height difference between the driving movable comb teeth 114 of the first planar area 110 and the driving fixed comb teeth 121 of the second planar area 120.

[0060] Specifically, when the electrostatic flat-plate driver does not apply the DC bias voltage V0, the driving fixed comb teeth 121 and the driving movable comb teeth 114 of the electrostatic comb driver are at the same height without a vertical height difference. After the electrostatic flat-plate driver applies the DC bias voltage V0, the vertically moving micromirror 111 generates a height difference in the first direction between the driving fixed comb teeth 121 and the driving movable comb teeth 114 under the downward pulling force of the DC bias voltage V0 of the electrostatic flat-plate driver, forming "bias-induced vertical comb teeth". A driving voltage is applied to the electrostatic comb driver to provide a driving force for pulling up the vertically moving micromirror 111. The accelerated motion of the vertically moving micromirror 111 downward along the first direction is driven by the electrostatic flat-plate driver, and the accelerated motion of the vertically moving micromirror 111 upward along the first direction is driven by a combined driving force combining the rebound force of the elastic beam 112 and the static straight comb driver.

[0061] In one embodiment, the vertical motion micromirror 111 is a circular plane reflector with a diameter of 100 to 1000 μm and a thickness of 5 to 50 μm, and its surface is coated with an optical high-reflection film, and the reflective film type is gold, silver, aluminum or a dielectric film; the movement mode of the vertical motion micromirror 111 is quasi-static vertical motion, and its movement range is 0.25 to 20 working laser wavelengths.

[0062] In one embodiment, the vertical motion micromirror 111 is a circular plane reflector with a diameter of 350 μm and a thickness of 25 μm. Its surface is coated with an optically highly reflective film. The reflective film is a composite thin film composed of 50 nm thick Ti and 200 nm thick Au, and has a high reflectivity of up to 98.5% at an operating wavelength of 1550 nm. The vertical motion micromirror 111 moves perpendicularly to the MEMS chip, using a quasi-static vertical motion mode. Its range of motion is 1550 nm, resulting in an optical phase shift of 4π radians for the high-speed MEMS optical phase shifter 100.

[0063] In one embodiment, the number of the elastic beams 112 is M (M is an even number, M=4 or 6 or 8), the elastic beams 112 are serpentine beams or straight beams, and are made of the same silicon thin film as the vertical motion micromirror 111 .

[0064] In one embodiment, the driving fixed comb teeth 121 and the driving movable comb teeth 114 are divided into M groups of comb teeth electrodes 1, 2, ..., M by M elastic beams 112, and the driving fixed comb teeth 121 of each group of comb teeth are electrically interconnected.

[0065] In one embodiment, Figure 2As shown, there are four symmetrically distributed elastic beams 112, which are arranged symmetrically with the center point of the vertical motion micromirror 111 as the center of symmetry; the elastic beam 112 structure is a straight beam, 300μm long, 13μm wide, and 25μm high, and is symmetrically distributed around the vertical motion micromirror 111. It is made of the same silicon film as the vertical motion micromirror 111; the connection between the elastic beam 112 and the vertical motion micromirror 111 is "chamfered" to reduce the maximum stress caused by the vertical motion, and at the same time, it can also reduce the dynamic deformation of the vertical motion micromirror 111.

[0066] In this embodiment, Figure 2 As shown, the displacement sensor includes fixed sensing comb teeth 151 and moving sensing comb teeth 152. The moving sensing comb teeth 152 are fixedly connected to the vertical motion micromirror 111. The fixed sensing comb teeth 151 are fixedly connected to the second peripheral structure layer 122. The fixed sensing comb teeth 151 and the moving sensing comb teeth 152 are arranged in an interlaced manner to form the displacement sensor.

[0067] The present invention sets the displacement sensor as a comb capacitor, so that a part originally used in the electrostatic comb driver can be directly modified into a displacement sensor by modifying the electrode connection method. The preparation structure is simple and occupies a small space, which is conducive to the miniaturization of high-speed optical phase shifting equipment.

[0068] In one embodiment, Figure 2 As shown, the sensing fixed comb teeth 151 and the driving fixed comb teeth 121 are located in the same plane, and the sensing movable comb teeth 152 and the driving movable comb teeth 114 are located in the same plane.

[0069] The present invention can further reduce the volume of the high-speed MEMS optical phase shifter 100 and improve the integration level by arranging the corresponding sensing comb teeth and driving comb teeth on the same plane.

[0070] In one embodiment, Figure 2 As shown, the sensing fixed comb teeth 151, the sensing moving comb teeth 152, the driving fixed comb teeth 121, and the driving moving comb teeth 114 are all centrally symmetrical with the center of the vertical motion micromirror 111, and the sensing fixed comb teeth 151, the sensing moving comb teeth 152, the driving fixed comb teeth 121, and the driving moving comb teeth 114 are all distributed along the radial direction of the vertical motion micromirror 111.

[0071] In one embodiment, when the electrostatic flat-plate driver does not apply the DC bias voltage V0, the heights of the movable comb tooth group and the fixed comb tooth group are consistent; after the electrostatic flat-plate driver applies the DC bias voltage V0, a ​​height difference is generated between the movable comb tooth group and the fixed comb tooth group, forming four groups of "bias-induced vertical comb teeth". Among them, two groups of dynamic comb teeth groups and corresponding fixed comb teeth groups are electrostatic driven comb teeth groups consisting of driven fixed comb teeth 121 and driven dynamic comb teeth 114. These two groups of driven fixed comb teeth 121 are electrically interconnected. A driving voltage is applied to these two groups of driven fixed comb teeth 121 to form two groups of vertical electrostatic comb teeth drivers, which provide a driving force for pulling up the vertical motion micromirror 111; the other two groups of dynamic comb teeth groups and corresponding fixed comb teeth groups are capacitive sensing comb teeth groups consisting of sensing dynamic comb teeth 152 and sensing fixed comb teeth 151. The two groups of sensing fixed comb teeth 151 are electrically interconnected to form two groups of vertical comb teeth sensing capacitors. These two groups of vertical comb teeth sensing capacitors are connected in parallel to each other and can detect the vertical motion displacement of the vertical motion micromirror 111 along the first direction. With the cooperation of the sensing detection circuit chip 608 of the high-speed MEMS optical phase shifter package structure 600 in Example 5, real-time detection of the vertical displacement of the vertical motion micromirror 111 is achieved; the electrostatic drive comb tooth group and the capacitive sensing comb tooth group are respectively distributed in a centrally symmetrical manner with the center point of the vertical motion micromirror 111 as the center of symmetry.

[0072] In one embodiment, Figure 2 As shown, the vertical comb teeth caused by the bias are divided into two groups, and all the fixed comb teeth in each group are electrically interconnected; one group is the driving fixed comb teeth 121 and the driving dynamic comb teeth 114 of the electrostatic comb tooth driver, which realize the upward off-plane electrostatic drive of the vertical motion micromirror 111; the other group is the sensing fixed comb teeth 151 and the sensing dynamic comb teeth 152 of the displacement sensor, which realize the real-time detection of the displacement of the vertical motion micromirror 111 with the cooperation of the sensing detection circuit chip 608, and the comb teeth of these two groups are respectively distributed in a centrally symmetrical manner with the center point of the vertical motion micromirror 111 as the center.

[0073] In one embodiment, there are four groups of dynamic comb teeth for driving the dynamic comb teeth 114 and the transmission dynamic comb teeth 152, the number of dynamic comb teeth in each group of dynamic comb teeth is 9, the total number of dynamic comb teeth is 36, each dynamic comb tooth is 506 μm long, the average width is 6.2 μm, the height is 25 μm, the shape is rectangular, and it is symmetrically distributed along the radial direction of the vertical motion micromirror 111, and is made of the same silicon thin film as the vertical motion micromirror 111.

[0074] In one embodiment, Figure 2As shown, the second planar region 120 includes four groups of second peripheral structure layers 122 and four groups of fixed comb teeth. The first planar region 110 includes four groups of first peripheral structure layers 113. The fixed comb teeth groups are connected to the substrate layer 140 and extend from the substrate layer 140 to above the air gap 130. Each fixed comb tooth group has nine fixed comb teeth, each with a length of 506 μm, a minimum width of 1.7 μm, and a maximum width of 47.08 μm. The fixed comb teeth groups are distributed in the shape of a sector arc with a vertex angle of approximately 0.542° and a height of 25 μm. The gap angle between the fixed comb teeth is 1.146°. The fixed comb tooth groups and the vertical motion micromirror 111 are made of the same silicon thin film.

[0075] In one embodiment, the high-speed MEMS optical phase shifter 100 further includes a pad electrically connected to the vertical motion micromirror 111, the flat driving electrode 141, the driving fixed comb teeth 121 and the driving movable comb teeth 114 of the electrostatic comb driver, and the displacement sensor.

[0076] In one embodiment, Figure 1-Figure 3 As shown, the pad electrically connected to the vertical motion micromirror 111 is a ground pad 161, the pad connected to the flat drive electrode 141 is a flat electrode pad 162, the pad connected to the electrostatic comb driver is a drive comb pad 163, and the pad connected to the displacement sensor is a sensing comb pad 164; the pads are electrically isolated by etching an insulating groove 165, and the pads are arranged on both sides of the high-speed MEMS optical phase shifter 100.

[0077] In one embodiment, the four groups of fixed comb teeth in the second planar area 120 are divided into two groups: driving fixed comb teeth 121 and sensing fixed comb teeth 151; the driving fixed comb teeth 121 are electrically connected to the programmable analog power supply V2 through the driving comb tooth pads 163 thereon, providing a driving voltage signal for the electrostatic comb tooth driver; the sensing fixed comb teeth 151 are connected to the sensing detection circuit chip 608 through the sensing comb tooth pads 164 thereon, leading to the detection electrical signal of the displacement sensor.

[0078] In one embodiment, Figure 2 As shown, four groups of first peripheral structure layers 113 are bonded to the third peripheral structure layer 142 of the substrate layer 140 via gold-gold bonding. Two groups of first peripheral structure layers 113 also have ground pads 161 connected to a ground voltage source VGND. The groups of first peripheral structure layers 113 are electrically isolated by etching insulating trenches 165.

[0079] Specifically, four groups of fixed comb teeth are connected to the third peripheral structure layer 142 of the substrate layer 140, and the movable comb tooth group is connected to the vertical motion micromirror 111. The fixed comb tooth groups and the corresponding movable comb teeth are arranged alternately; each movable comb tooth is located in the middle of the fixed comb tooth gap, and the average spacing between the movable comb teeth and the adjacent fixed comb teeth is 4μm, and they are distributed radially in a centrally symmetrical manner with the vertical motion micromirror 111 as the center.

[0080] Specifically, the third peripheral structure layer 142 also serves as a supporting substrate for the entire high-speed MEMS optical phase shifter 100 .

[0081] In one embodiment, Figure 1-Figure 3 As shown, the air gap 130 is an air gap 130 between the vertical motion micromirror 111, the elastic beam 112 and the flat driving electrode 141, and serves as an active gap for the vertical motion micromirror 111 and the elastic beam 112 to move vertically up and down along the first direction.

[0082] In one embodiment, the thickness of the air gap 130 in the first direction is several micrometers to tens of micrometers.

[0083] In one embodiment, the gap between the flat driving electrode 141 and the vertical motion micromirror 111 is 8 microns.

[0084] In one embodiment, Figure 3 As shown, flat electrode pads 162 are symmetrically distributed on both sides of the air gap 130 on the third peripheral structure layer 142 .

[0085] In one embodiment, the electrostatic flat panel driver uses a dual power supply consisting of a DC bias power supply V0 and a programmable analog power supply V1 to achieve electrostatic driving of the vertical motion micromirror 111 downward along a first direction; the programmable analog power supply V1 is a high-precision analog power supply with controllable positive and negative polarities, and the absolute value of its adjustable range is less than or equal to the DC bias power supply voltage V0.

[0086] In one embodiment, the electrostatic comb driver is driven by a programmable analog power supply V2, which is a unipolar high-precision analog power supply, and drives the vertical motion micromirror 111 to move vertically upward rapidly along a first direction.

[0087] In one embodiment, the vertical motion micromirror 111 and the flat-plate drive electrode 141 constitute an electrostatic flat-plate driver. The flat-plate electrode pad 162 is connected to a dual power supply comprising a DC bias power supply V0 (in this embodiment, V0 = 100V) and a programmable analog power supply V1 (in this embodiment, V1 is a ±60V high-precision power supply with controllable positive and negative polarity) to achieve downward electrostatic drive of the vertical motion micromirror 111. The DC bias power supply V0 drives the vertical motion micromirror 111 to pull down a displacement d0 that is greater than half of the vertical displacement of 1.55 μm corresponding to the maximum optical phase shift of the high-speed MEMS optical phase shifter 100, i.e., 0.775 μm. In this embodiment, d0 is set to 0.85 μm.

[0088] In one embodiment, the electrostatic comb driver and the electrostatic flat plate driver can drive the vertical motion micromirror 111 to move along the first direction by an amount greater than half of the maximum optical phase shift of the vertical motion micromirror 111 in the high-speed MEMS optical phase shifter 100 .

[0089] The present invention ensures that the displacement of the vertically movable micromirror 111 by the two drivers is greater than half of the maximum optical phase shift that the vertically movable micromirror 111 can achieve within the high-speed MEMS optical phase shifter 100. This ensures that each of the two drivers can drive the vertically movable micromirror 111 to a displacement of half of the maximum optical phase shift. This ensures that the total displacement of the vertically movable micromirror 111 by the two drivers is greater than the maximum optical phase shift allowed within the high-speed MEMS optical phase shifter 100. This fully utilizes the available phase shift space within the high-speed MEMS optical phase shifter 100 and maximizes the achievable phase shift range of the high-speed MEMS optical phase shifter 100. Specifically, the maximum optical phase shift that the vertically movable micromirror 111 can achieve within the high-speed MEMS optical phase shifter 100 corresponds to the maximum distance that the vertically movable micromirror 111 can move within the air gap 130 in the first direction, which is approximately equal to the difference between the thickness of the air gap 130 in the first direction and the thickness of the vertically movable micromirror 111 in the first direction.

[0090] In one embodiment, the output signal bandwidth of the displacement sensor is greater than or equal to 2-10 times the working bandwidth of the high-speed MEMS optical phase shifter 100 .

[0091] The present invention sets the output signal bandwidth of the displacement sensor to be greater than or equal to 2-10 times the operating bandwidth of the high-speed MEMS optical phase shifter 100. This ensures that the output signal of the displacement sensor can provide timely feedback of the real-time displacement of the high-speed MEMS optical phase shifter 100, thereby enabling high-speed real-time feedback control of the driver and ensuring the realization of the operating bandwidth and phase shifting accuracy of the high-speed MEMS optical phase shifter 100.

[0092] In one embodiment, the displacement sensed by the displacement sensor is used to control the driving states of the electrostatic comb driver and the electrostatic flat plate driver through closed-loop feedback using a PID (Proportion Integral Differential) algorithm.

[0093] The present invention uses a PID algorithm to perform feedback control on the driving state of the high-speed MEMS optical phase shifter 100, thereby further improving the control accuracy and speed of the phase shift amount, thereby ensuring high speed and high precision of the optical phase shift.

[0094] In one embodiment, a PID closed-loop feedback control is used to vertically move the vertical micromirror 111 in a first direction and generate an optical phase shift. During the downward acceleration of the vertical micromirror 111 in the first direction, an electrostatic plate driver and the upward rebound force of the elastic beam 112 are combined to provide acceleration. During the upward acceleration of the vertical micromirror 111, the upward driving force of the electrostatic comb driver is used to provide upward acceleration. Simultaneously, the upward rebound force of the elastic beam 112 serves as the driving force for the upward acceleration, and the downward driving force of the electrostatic plate driver serves as a driving resistance to control the upward acceleration. A displacement sensor composed of the fixed sensing comb teeth 151 and the moving sensing comb teeth 152 provides a vertical displacement signal of the vertical micromirror 111 to the feedback control chip 609 in the PID closed-loop feedback control. Under the feedback control of the electrostatic comb driver and the electrostatic plate driver by the feedback control chip 609, feedback control of the vertical displacement of the vertical micromirror 111, i.e., the optical phase shift, is achieved. In this embodiment, the operating bandwidth of the displacement sensor is 500 kHz, which is five times the operating bandwidth of the high-speed MEMS optical phase shifter 100 , which is 100 kHz.

[0095] Example 2:

[0096] This embodiment provides a high-speed MEMS optical phase shifter 100. The high-speed MEMS optical phase shifter 100 has substantially the same features as the high-speed MEMS optical phase shifter 100 in Example 1, except that:

[0097] In this embodiment, Figure 5-Figure 7 As shown, Figure 5 is a top view of the substrate layer 140, Figure 6 for Figure 5 A partial enlarged view of Figure 7FIG2 is a top view of the second planar region 120 of the high-speed MEMS optical phase shifter 100. The displacement sensor includes a ring electrode 251 and the vertical motion micromirror 111. The ring electrode 251 is fixed to the bottom of the groove 143 and surrounds the flat plate drive electrode 141. The ring electrode 251 is electrically isolated from the flat plate drive electrode 141. The ring electrode 251 overlaps with the projections of the vertical motion micromirror 111 and / or the elastic beam 112 on the substrate layer 140. The groove 143 between the ring electrode 251 and the vertical motion micromirror 111 and / or the elastic beam 112 forms an air gap 130 to form the displacement sensor.

[0098] By disposing the annular electrode 251 around the flat-plate drive electrode 141, the present invention can simultaneously fabricate the annular electrode 251 during the patterning process of the flat-plate drive electrode 141, thereby ensuring that the fabrication efficiency of the integrated displacement sensor does not reduce the fabrication efficiency of the high-speed MEMS optical phase shifter 100. Furthermore, the comb tooth group can be driven solely as an electrostatic comb tooth driver without separating part of the comb tooth group for displacement sensing, thereby further increasing the driving force and thus the optical phase shifting speed.

[0099] Specifically, the "ring-shaped" of the ring-shaped electrode 251 only refers to the periphery of the flat-plate driving electrode 141 and does not need to completely surround the flat-plate driving electrode 141. The surrounding range, size and position can be adjusted according to needs and are within the scope of protection of the present invention.

[0100] In one embodiment, the annular electrode 251 only overlaps with the projection of the vertical motion micromirror 111 on the substrate layer 140 , and the groove 143 between the annular electrode 251 and the vertical motion micromirror 111 forms an air gap 130 to constitute the displacement sensor.

[0101] In one embodiment, the annular electrode 251 only overlaps with the projection of the elastic beam 112 on the substrate layer 140 , and the groove 143 between the annular electrode 251 and the elastic beam 112 forms an air gap 130 to constitute the displacement sensor.

[0102] In one embodiment, the annular electrode 251 has overlapping portions with projections of the vertical motion micromirror 111 and the elastic beam 112 on the substrate layer 140, and the groove 143 between the annular electrode 251 and the vertical motion micromirror 111 and the elastic beam 112 forms an air gap 130 to constitute the displacement sensor.

[0103] Specifically, if Figure 5 As shown, the annular electrodes 251 are also electrically connected to corresponding annular electrode pads 252 to lead out electrical connections to required components.

[0104] Example 3:

[0105] This embodiment provides a high-speed MEMS optical phase shifter 100. The high-speed MEMS optical phase shifter 100 has substantially the same features as the high-speed MEMS optical phase shifter 100 in Example 1, except that:

[0106] In this embodiment, Figure 8 FIG. 1 is a schematic side cross-sectional view of the high-speed MEMS optical phase shifter 100 . The displacement sensor includes a strain gauge piezoresistor 351 and a reference resistor 352 . The strain gauge piezoresistor 351 is located on the elastic beam 112 , and the reference resistor 352 is located on the overall structural layer. The strain gauge piezoresistor 351 and the reference resistor 352 are electrically connected to form a Wheatstone bridge circuit, which constitutes the displacement sensor.

[0107] The present invention forms a Wheatstone bridge circuit by setting a strain gauge piezoresistor 351 and a reference resistor 352. When the elastic beam 112 generates strain as the vertically moving micromirror 111 is displaced, the resistance of the strain gauge piezoresistor 351 changes. When the input electrical signal 355 of the Wheatstone bridge circuit remains unchanged, the changed resistance of the strain gauge piezoresistor 351 causes the output electrical signal 356 of the Wheatstone bridge circuit to change. By calculating the change in the output electrical signal 356, the change in the resistance of the strain gauge piezoresistor 351 can be obtained. The stress change of 12 is linearly related to the displacement of the vertical motion micromirror 111. Therefore, the displacement of the vertical motion micromirror 111 corresponding to the output electrical signal 356 can be obtained by performing displacement calibration between the output electrical signal 356 of the Wheatstone bridge circuit and the displacement of the vertical motion micromirror 111. Since the strain gauge piezoresistor 351 and the reference resistor 352 can be directly obtained through processes such as semiconductor ion implantation, no additional structure is required, which is conducive to further miniaturization, lightweighting, and low power consumption of the high-speed MEMS optical phase shifter 100.

[0108] Preferably, the strain piezoresistor 351 is disposed at a position where the elastic beam 112 has the maximum strain.

[0109] In one embodiment, the strain gauge varistor 351 is formed by performing a semiconductor ion implantation process on the elastic beam 112 .

[0110] In one embodiment, the strain gauge piezoresistor 351 and the reference resistor 352 are connected via metal wires 353 to form a Wheatstone bridge circuit.

[0111] In one embodiment, the Wheatstone bridge circuit may include one or more Wheatstone bridges, and the number and position of the strain gauge piezoresistors 351 and the reference resistors 352 may be adjusted according to the needs of the Wheatstone bridge circuit.

[0112] In one embodiment, Figure 9 FIG. 1 shows an electrical connection diagram of a Wheatstone bridge circuit. The Wheatstone bridge circuit includes a Wheatstone bridge composed of two strain gauge piezoresistors 351, two reference resistors 352, and a metal lead 353. The metal lead 353 also extends the electrical connection between the strain gauge piezoresistors 351 and the reference resistors 352 to a resistor pad 354. The Wheatstone bridge circuit is connected to an external input electrical signal 355 and an output electrical signal 356 through the resistor pad 354. The input electrical signal 355 is the power supply voltage, and the output electrical signal 356 is the voltage difference between the two ends of the interface. By measuring the change in the output electrical signal 356, the corresponding phase shift of the vertical motion micromirror 111 can be measured.

[0113] Example 4:

[0114] This embodiment provides a high-speed MEMS optical phase shifter array 400. The high-speed MEMS optical phase shifter array 400 includes n high-speed MEMS optical phase shifters 100 according to any one of Embodiments 1-3 arranged in an array, where n is greater than or equal to 2, and two adjacent high-speed MEMS optical phase shifters 100 are electrically insulated from each other.

[0115] The present invention forms a phase shifter array by disposing the high-speed MEMS optical phase shifters 100 in Examples 1-3, which is conducive to meeting the application requirements of optical devices that require a phase shift array.

[0116] In one embodiment, n high-speed MEMS optical phase shifters 100 are arranged in a linear array.

[0117] In one embodiment, Figure 10 As shown, the high-speed MEMS optical phase shifter array 400 is composed of six identical and independent high-speed MEMS optical phase shifters 100 described in any one of Embodiments 1-3 arranged in a line.

[0118] In one embodiment, n high-speed MEMS optical phase shifters 100 are arranged in an a×b square array, where a and b are both integers greater than or equal to 2.

[0119] In one embodiment, a and b are both integers greater than or equal to 3.

[0120] In one embodiment, Figure 11 As shown, the four high-speed MEMS optical phase shifters 100 are arranged into a 2×2 high-speed MEMS optical phase shifter array 400 .

[0121] Specifically, the n high-speed MEMS optical phase shifters 100 may also be arranged in other array shapes as required.

[0122] Example 5:

[0123] This embodiment provides a high-speed MEMS optical phase shifter package structure 600, which includes a high-speed MEMS optical phase shifter chip 500 formed by the high-speed MEMS optical phase shifter 100 described in any one of Embodiments 1-3 or / and the high-speed MEMS optical phase shifter array 400 described in any one of Embodiment 4.

[0124] like Figure 12 As shown, the high-speed MEMS optical phase shifter packaging structure 600 further includes an electric drive chip 607, a sensor detection circuit chip 608, a feedback control chip 609, and an input / output connector 604; the electric drive chip 607 is electrically connected to the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100, and is used to drive the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100 (providing driving power for the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100); the sensor detection circuit chip 608 is electrically connected to the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100, and is used to drive the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100 (providing driving power for the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter 100); The displacement sensor is electrically connected to process the sensing electrical signal of the displacement sensor; the input / output connector 604 is electrically connected to the external control system to receive the target electrical signal; the feedback control chip 609 is electrically connected to the electric drive chip 607, the sensing detection circuit chip 608, and the input / output connector 604, and is used to receive the sensing electrical signal from the sensing detection circuit chip 608 and the target electrical signal received by the input / output connector 604, and calculate the driving signal required for the vertical motion micromirror 111 to perform vertical displacement and provide it to the electric drive chip 607, so as to control the phase shift amount of the high-speed MEMS optical phase shifter 100 through closed-loop feedback.

[0125] Specifically, the feedback control chip 609 is also electrically connected to an external control system that transmits phase control information.

[0126] Specifically, the sensing detection circuit chip 608 electrically connected to the displacement sensor in Examples 1-2 is a capacitance detection chip, and the sensing detection circuit chip 608 electrically connected to the displacement sensor in Example 3 is a resistance detection chip.

[0127] In one embodiment, Figure 12As shown, the high-speed MEMS optical phase shifter packaging structure 600 further includes a PCB board 610 (Printed Circuit Board), a dual-fiber collimator 605 and a packaging structure;

[0128] The PCB board 610 is used to carry the high-speed MEMS optical phase shifter 100, the electric drive chip 607 for driving the electrostatic comb driver and the electrostatic plate driver, the sensor detection circuit chip 608 for processing the sensing electrical signal of the displacement sensor, and the feedback control chip 609 for receiving the sensing electrical signal and the phase control information transmitted by the external control system and calculating the electrical signal required for the vertical displacement of the vertical motion micromirror 111 to control the electric drive chip 607 to realize electrostatic driving, and is connected to the input / output connector 604 for transmitting electrical signals;

[0129] The dual-fiber collimator 605 includes an input single-mode fiber, an output single-mode fiber, and a collimating lens;

[0130] The packaging structure includes a packaging cavity 606 that carries a PCB board 610 and a perforated upper cover 601 that fixes the dual-fiber collimator 605 , thereby realizing optoelectronic packaging of the high-speed MEMS optical phase shifter 100 .

[0131] In one embodiment, the high-speed MEMS optical phase shifter chip 500 uses a redistribution layer (RDL) to connect the pads in the high-speed MEMS optical phase shifter array 400 and / or the high-speed MEMS optical phase shifter 100 to the periphery of the high-speed MEMS optical phase shifter array 400 chip, thereby facilitating subsequent packaging and bonding.

[0132] In one embodiment, Figure 12 As shown, the package cavity 606 of the package structure is formed by enclosing an upper cover plate 601 and a package shell 602, and the upper cover plate 601 and the package shell 602 are made of aluminum alloy. The package structure includes a high-speed MEMS optical phase shifter chip 500 composed of a high-speed MEMS optical phase shifter 100 and / or a high-speed MEMS optical phase shifter array 400. On the bottom plate of the package shell 602, a circuit chip 603, a PCB board 610, a high-speed MEMS optical phase shifter array 400 chip, and an input / output connector 604 are arranged in order from bottom to top. The circuit chip 603 includes an electric drive chip 607, a sensor detection circuit chip 608, and a feedback control chip 609. The input / output connector 604 is led out by a flexible cable 611. The electric drive chip 607, the sensor detection circuit chip 608, and the feedback control chip 609 are soldered to the back of the PCB board 610 by flip-chip solder balls 612.

[0133] In one embodiment, the circuit chip 603 , including the electric driving chip 607 , the sensor detection circuit chip 608 and the feedback control chip 609 , can be further integrated into an application specific integrated circuit (ASIC).

[0134] Specifically, the PCB board 610 is a multi-layer board, and the components in the package structure are electrically connected or electrically insulated through the traces under the PCB board 610. The size of the PCB board 610 is 25mm*12mm. Figure 12 As shown, the MEMS optical phase shifter array chip is adhered to the upper surface of the PCB board 610 through thermal conductive adhesive 613, and is electrically connected and transmits signals to the PCB board 610 through bonding wires 614; the input / output connector 604 is flip-chip soldered on the upper surface of the PCB board 610.

[0135] In one embodiment, Figure 12 As shown, a dual-fiber collimator 605 is mounted on the upper cover 601, corresponding to the vertically moving micromirror 111 in the high-speed MEMS optical phase shifter 100. The upper cover 601 is used to support the dual-fiber collimator 605 and is made of the same material as the package 602. A hole corresponding to the vertically moving micromirror 111 is formed on the upper cover 601, and the diameter of the hole is slightly larger than the outer diameter of the dual-fiber collimator 605. The dual-fiber collimator 605 includes an input optical fiber 615, an output optical fiber 616, and a rod lens C-Lens 617. The input fiber 615 provides external optical signal input to the high-speed MEMS optical phase shifter 100. The rod lens C-Lens 617 collimates the optical signal from the input fiber 615. The dual-fiber collimator is precisely adjusted using a precision optical adjustment mount to minimize insertion loss (typically within the range of 0.2-0.3 dB) after the input optical signal is reflected by the vertically moving micromirror 111 and emitted to the output fiber 616. The output fiber 616 then transmits the phase-shifted optical signal to the outside. The specific installation method involves inserting the prefabricated dual-fiber collimator 605 into the corresponding hole, precisely aligning it, and then securing it to the upper cover 601 with adhesive. Specifically, UV adhesive is first used for quick fixation, followed by a thermal curing agent for enhanced fixation. Within the high-speed MEMS optical phase shifter array 400 chip, each dual-fiber collimator 605 is sequentially assembled with the corresponding high-speed MEMS optical phase shifter 100.

[0136] In one embodiment, Figure 12As shown, when the high-speed MEMS optical phase shifter chip 500 in the high-speed MEMS optical phase shifter package structure 600 includes the high-speed MEMS optical phase shifter array 400, the dual-fiber collimator 605 corresponding to the high-speed MEMS optical phase shifter array 400 is a dual-fiber collimator 605 array. The dual-fiber collimator 605 array includes a dual-fiber collimator 605 corresponding to each high-speed MEMS optical phase shifter 100. The spacing between two adjacent dual-fiber collimators 605 is consistent with the spacing between the centers of the vertical motion micromirrors 111 of the corresponding two high-speed MEMS optical phase shifters 100.

[0137] Example 6:

[0138] This embodiment provides an optical device, comprising a high-speed MEMS optical phase shifter device consisting of the high-speed MEMS optical phase shifter 100 described in any one of Embodiments 1-3, the high-speed MEMS optical phase shifter array 400 described in any one of Embodiment 4, or / and the high-speed MEMS optical phase shifter packaging structure 600 described in any one of Embodiment 5.

[0139] The present invention uses the high-speed MEMS optical phase shifter 100 in Examples 1-3 in optical devices, utilizing MEMS phase shifters that increase phase shift speed and reduce cost, power consumption, and volume, to meet the needs of some optical devices requiring high-speed phase shifting.

[0140] In one embodiment, the optical device is an optical interferometer, an interferometric fiber optic sensor, a laser beam shaping device, a laser wavefront correction device, an optical phased array device, or a vector optical phased array device.

[0141] In summary, the high-speed MEMS optical phase shifter, its array, packaging structure, and optical device of the present invention can respectively drive the displacement of the vertically moving micromirror in two opposite directions by forming a dual-drive structure using electrostatic comb teeth and an electrostatic plate, thereby achieving high-speed optical phase shifting with a simple structure. At the same time, the control accuracy of the phase shifter's phase shift amount is improved through the combination of closed-loop feedback control and the dual-drive structure. In addition, achieving high-speed phase shifting through the MEMS phase shifter is conducive to the realization of a low-cost, low-power, and small-sized high-speed phase shifting device. Finally, by integrating a displacement sensor into the MEMS phase shifter, a low-cost, low-power, and small-sized high-speed phase shifting device can be further realized.

[0142] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0143] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A high-speed MEMS optical phase shifter, characterized in that: The high-speed MEMS optical phase shifter includes: a silicon film, a substrate layer, and a displacement sensor, wherein the silicon film includes a first planar region and a second planar region, and the first planar region, the second planar region, and the substrate layer are all perpendicular to a first direction; The first planar region includes a vertical motion micromirror, an elastic beam, a driving comb tooth, and a first peripheral structure layer, wherein the elastic beam is symmetrically distributed with the center of the vertical motion micromirror as the center point, the vertical motion micromirror is elastically connected to the first peripheral structure layer via the elastic beam, and the driving comb tooth is fixedly connected only to the vertical motion micromirror; the second planar region includes driving fixed comb teeth and a second peripheral structure layer, wherein the driving fixed comb teeth are fixedly connected to the second peripheral structure layer; the driving fixed comb teeth and the driving comb teeth are staggered with each other to form an electrostatic comb tooth driver, and the driving direction of the electrostatic comb tooth driver is along the first direction toward a direction away from the substrate layer; The substrate layer includes a flat plate driving electrode and a third peripheral structure layer, the third peripheral structure layer is provided with a groove, and the flat plate driving electrode is fixed to the bottom of the groove; the flat plate driving electrode and the projection of the vertical motion micromirror on the substrate layer have an overlapping portion, and the groove between the flat plate driving electrode and the vertical motion micromirror forms an air gap to form an electrostatic flat plate driver, and the driving direction of the electrostatic flat plate driver is along the first direction toward the substrate layer; the first peripheral structure layer, the second peripheral structure layer, and the third peripheral structure layer are fixedly connected to form an overall structure layer; The displacement sensor is used to sense the displacement of the vertically moving micromirror along the first direction. The displacement sensed by the displacement sensor is used to indicate the phase shift of the high-speed MEMS optical phase shifter and to adjust the driving states of the electrostatic comb driver and the electrostatic flat plate driver through closed-loop feedback to control the motion state of the vertically moving micromirror along the first direction.

2. The high-speed MEMS optical phase shifter according to claim 1, wherein: The displacement sensor includes fixed sensing comb teeth and moving sensing comb teeth. The moving sensing comb teeth are fixedly connected to the vertical motion micromirror. The fixed sensing comb teeth are fixedly connected to the second peripheral structure layer. The fixed sensing comb teeth and the moving sensing comb teeth are arranged in an interlaced manner corresponding to each other to form the displacement sensor.

3. The high-speed MEMS optical phase shifter according to claim 1, wherein: The displacement sensor includes a ring-shaped electrode and the vertical motion micromirror. The ring-shaped electrode is fixed to the bottom of the groove and surrounds the flat-plate driving electrode. There is electrical isolation between the ring-shaped electrode and the flat-plate driving electrode. The ring-shaped electrode has an overlapping portion with the projection of the vertical motion micromirror and / or the elastic beam on the substrate layer. The groove between the ring-shaped electrode and the vertical motion micromirror and / or the elastic beam forms an air gap to constitute the displacement sensor.

4. The high-speed MEMS optical phase shifter according to claim 1, wherein: The displacement sensor includes a strain piezoresistor and a reference resistor, the strain piezoresistor is located on the elastic beam, the reference resistor is located on the overall structural layer, the strain piezoresistor and the reference resistor are electrically connected to form a Wheatstone bridge circuit, and the Wheatstone bridge circuit constitutes the displacement sensor.

5. The high-speed MEMS optical phase shifter according to claim 1, wherein: The output signal bandwidth of the displacement sensor is greater than or equal to 2-10 times the working bandwidth of the high-speed MEMS optical phase shifter.

6. The high-speed MEMS optical phase shifter according to claim 1, wherein: The displacement amount sensed by the displacement sensor is used to control the driving states of the electrostatic comb driver and the electrostatic flat plate driver through a PID algorithm closed-loop feedback.

7. A high-speed MEMS optical phase shifter array, characterized in that: The high-speed MEMS optical phase shifter array comprises n high-speed MEMS optical phase shifters according to any one of claims 1 to 6 arranged in an array, where n is greater than or equal to 2, and two adjacent high-speed MEMS optical phase shifters are electrically insulated from each other.

8. The high-speed MEMS optical phase shifter array according to claim 7, wherein: The n high-speed MEMS optical phase shifters are arranged in a straight line array; or the n high-speed MEMS optical phase shifters are arranged in an a×b square array, where a and b are both integers greater than or equal to 2.

9. A high-speed MEMS optical phase shifter packaging structure, characterized in that: The high-speed MEMS optical phase shifter packaging structure comprises the high-speed MEMS optical phase shifter according to any one of claims 1 to 6 or / and the high-speed MEMS optical phase shifter array according to any one of claims 7 to 8; The high-speed MEMS optical phase shifter packaging structure also includes an electric drive chip, a sensor detection circuit chip, a feedback control chip and an input / output connector; The electric drive chip is electrically connected to the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter, and is used to drive the electrostatic comb driver and the electrostatic plate driver of the high-speed MEMS optical phase shifter; The sensing detection circuit chip is electrically connected to the displacement sensor of the high-speed MEMS optical phase shifter and is used to process the sensing electrical signal of the displacement sensor; the input / output connector is electrically connected to the external control system to receive the target electrical signal; the feedback control chip is electrically connected to the electric drive chip, the sensing detection circuit chip, and the input / output connector and is used to receive the sensing electrical signal of the sensing detection circuit chip and the target electrical signal received by the input / output connector, calculate the driving signal required for the vertical motion micromirror to perform vertical displacement, and provide it to the electric drive chip to control the phase shift amount of the high-speed MEMS optical phase shifter through closed-loop feedback.

10. An optical device, characterized in that: The optical device includes a high-speed MEMS optical phase shifter device composed of the high-speed MEMS optical phase shifter according to any one of claims 1 to 6, the high-speed MEMS optical phase shifter array according to any one of claims 7 to 8, or / and the high-speed MEMS optical phase shifter packaging structure according to claim 9.

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