High-speed MEMS optical phase shifter, array thereof, packaging structure and optical equipment

Abstract

The invention provides a high-speed MEMS optical phase shifter, an array of the high-speed MEMS optical phase shifter, a packaging structure and optical equipment. In the phase shifter, driving fixed comb teeth of a second plane area and driving movable comb teeth of a first plane area form an electrostatic comb tooth driver; the panel driving electrode of the substrate layer and the vertical motion micromirror of the first plane area form an electrostatic panel driver; and the displacement sensor senses the displacement of the vertical motion micromirror and feeds back and controls the driving state in a closed loop. According to the invention, the dual-drive structure of the comb teeth and the flat plate respectively drives the vertically moving micro-mirror along two opposite directions, and the simple structure realizes high-speed optical phase shift; meanwhile, closed-loop feedback control and a dual-drive structure improve the phase shift control precision; in addition, high-speed phase shifting of the MEMS phase shifter meets the high-speed phase shifting application requirements of low cost, low power consumption and small size; and finally, integrating a displacement sensor in the MEMS chip, indicating the phase shift quantity of the MEMS optical phase shifter and performing closed-loop feedback adjustment on the driving states of the electrostatic comb tooth driver and the electrostatic flat driver, thereby improving the performance of the high-speed phase shifting equipment.

Description

Technical Field

[0001] The 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 an array, a packaging structure and an optical device thereof. Background Art

[0002] Optical phase is a key technical parameter of laser beam, and dynamic control of optical phase is a key technology of laser technology. It has broad application prospects in optical interferometers, interferometric fiber sensors, laser beam shaping, laser wavefront correction, optical phased arrays, etc. Optical phased array is a new laser scanning technology developed from microwave phased array. It extends the working wavelength of microwave phased array to laser wavelength. It is a new generation of technology for satellite laser communication. It can effectively solve the problems of large size, single pointing, heavy weight, large moment of inertia, high driving power consumption and high cost of optical scanning antenna in existing satellite laser communication systems, as well as solve a series of technical problems such as the difficulty of existing turntable optical scanning to meet the requirements of light, small and low-cost satellite Internet laser communication networking. Chinese scientific and technological personnel have proposed a vector optical phased array solution based on MEMS technology, breaking through the existing scalar optical phased array technology solution. It is a new optical phased array system with large-size array elements, large-angle scanning and multi-dimensional vector control. It only needs tens to hundreds of array elements to realize a space laser communication system with an equivalent aperture of 100 mm and a communication distance of thousands to tens of thousands of kilometers, which has good feasibility in engineering. 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] The optical device that realizes the dynamic control of the optical phase is called an optical phase modulator or an optical phase shifter. Its main function is to realize the control of the phase of the optical signal under the control of the control signal. According to the control principle of the optical phase, it is mainly divided into two mechanisms: optical path control and optical refractive index control. Optical path control is to realize the optical phase control by controlling the propagation optical path length of the light beam. The realization method is: 1) Normal movement of the optical reflector. As long as it moves half a wavelength, the phase of the reflected light will change by 2π radians. It has significant advantages such as simplicity, high efficiency, low optical loss, and polarization insensitivity. However, the use of a motor to drive the movement of the optical reflector has the disadvantages of large size, high driving power consumption, and slow modulation speed. The use of a piezoelectric stack to drive the movement of the optical reflector has the disadvantages of large size, high driving voltage, low modulation speed, poor linearity, and severe hysteresis. 2) The piezoelectric driver of the optical fiber stretches to realize the control of the phase of the optical signal by controlling the length of the optical fiber ring. It has low optical loss, but has the disadvantages of large size, high driving voltage of the piezoelectric driver, low modulation speed, poor linearity, severe hysteresis, and the stretching of the optical fiber disturbs the polarization state. The optical refractive index regulation is to achieve optical phase modulation by controlling the refractive index of the light propagation medium. The technical solutions are as follows: 1) Waveguide modulator based on electro-optic effect, mainly using LiNbO3 waveguide and electro-optic polymer waveguide, under the action of modulation voltage signal, the refractive index of the waveguide is changed by electro-optic effect to achieve optical phase modulation. Its advantages are extremely high phase modulation speed, which can reach 10GHz or even higher, low driving voltage and low power consumption, but there are shortcomings such as high optical loss, polarization sensitivity and high cost, which are generally only used for high-speed modulation of signals in optical communication systems; 2) Waveguide modulator based on thermo-optic effect, mainly using Si waveguide, SiN waveguide and optical fiber thermo-optic modulation; Thermo-optic modulation of Si waveguide and SiN waveguide can reach modulation bandwidth of tens of kHz, but there are shortcomings such as high modulation power consumption, insufficient modulation bandwidth, large optical loss and polarization sensitivity. Optical fiber thermo-optic modulation has low optical loss and polarization insensitivity, but there are shortcomings such as low modulation bandwidth, high modulation power consumption and large volume. 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 reflectors in a monolithic integrated manner, 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 reflectors. 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, which 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 cannot meet the requirements of high-speed modulation and arraying of MEMS phase shifters in 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 the present 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 described in the background technology part of the present 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 an array, a packaging structure and an optical device thereof, so as to solve the problem of limited phase shifting speed of the MEMS phase shifter in the prior art.

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

[0009] The first plane 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 through the elastic beam, and the driving comb tooth is only fixedly connected to the vertical motion micromirror;

[0010] The second planar area includes driving fixed comb teeth and a second peripheral structure layer, the driving fixed comb teeth are fixedly connected to the second peripheral structure layer; the driving fixed comb teeth and the driving movable comb teeth are arranged alternately 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;

[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, 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, 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 a total structure layer;

[0012] The displacement sensor is used to sense the displacement of the vertical motion 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 vertical motion 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-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, and there is electrical isolation between the ring-shaped electrode and the flat-plate driving electrode; the ring-shaped 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-shaped 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 varistor and a reference resistor, the strain varistor is located in the elastic beam, the reference resistor is located in the overall structural layer, the strain varistor 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, n being greater than or equal to 2, and two adjacent high-speed MEMS optical phase shifters being electrically insulated from each other.

[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 also 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 high-speed MEMS optical phase shifters described above or / and any one of the high-speed MEMS optical phase shifter arrays described above;

[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 the electrostatic flat plate driver of the high-speed MEMS optical phase shifter, and is used to drive the electrostatic comb driver and the electrostatic flat 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, and is used to process the sensing 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, and is used to receive the sensing electrical signal of the sensor detection circuit chip and the target electrical signal received by the input / output connector, and calculates the driving signal required for the vertical motion micromirror to perform vertical displacement and provides it to the electric drive chip, so as to control the phase shift amount 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, or / and 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 and its 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 flat plate to form a dual-drive structure to electrostatically drive the displacement of the vertically moving micromirror in two opposite directions, thereby solving the problem that the conventional electrostatic drive can only drive in one direction, and realizing 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 a MEMS optical phase shifter, which is conducive to realizing a high-speed optical phase shifting device with low cost, low power consumption and small volume;

[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 is a schematic diagram of the structure of the 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 is 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 It is a schematic 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 Example 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] Fig. 9 It shows the electrical connection diagram of the Wheatstone bridge circuit in Embodiment 3 of the present invention.

[0037] Fig.10 It is a schematic diagram showing the structure of a high-speed MEMS optical phase shifter array in an example of Embodiment 4 of the present invention.

[0038] Fig.11 It is a schematic diagram showing the structure of a high-speed MEMS optical phase shifter array in an example of Embodiment 4 of the present invention.

[0039] Fig.12 It is 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 plane area; 111, vertical motion micromirror; 112, elastic beam; 113, first peripheral structure layer; 114, driving comb teeth; 120, second plane area; 121, driving fixed comb teeth; 122, second peripheral structure layer; 130, air gap; 140, substrate layer; 141, flat driving electrode; 142, third peripheral structure layer; 143, groove; 151, sensing fixed comb teeth; 152, sensing moving comb teeth; 161, ground pad; 162, flat electrode pad; 163, driving comb pad; 164, sensing comb pad; 165, etching insulation groove;

[0042] 251, annular electrode; 252, annular electrode pad; 351, strain 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 flat cable; 612. Flip-chip solder ball; 613. Thermal conductive adhesive; 614. Bonding wire; 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, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 in detail, for the sake of convenience, the schematic diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, 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", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. 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 in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which 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 illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

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

[0051] Embodiment 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 4Schematic diagram of the structure of the substrate layer 140 in the high-speed MEMS optical phase shifter 100, the high-speed MEMS optical phase shifter 100 includes: a silicon film, a substrate layer 140 and a displacement sensor, the silicon film includes a first plane area 110 and a second plane area 120, the first plane area 110, the second plane area 120 and the substrate layer 140 are all perpendicular to the first direction;

[0053] The first planar region 110 includes a vertical motion micromirror 111, an elastic beam 112, a driving comb tooth 114 and a first peripheral structure layer 113, wherein the elastic beam 112 is symmetrically distributed with the center of the vertical motion micromirror 111 as the center point, the vertical motion micromirror 111 is elastically connected to the first peripheral structure layer 113 through the elastic beam 112, and the driving comb tooth 114 is only fixedly connected 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 movable comb teeth 114 are arranged alternately 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 140;

[0055] The substrate layer 140 includes a flat plate driving electrode 141 and a third peripheral structure layer 142, wherein the third peripheral structure layer 142 is provided with a groove 143, and the flat plate driving electrode 141 is fixed to the bottom of the groove 143; the flat plate driving electrode 141 and the projection of the vertical motion micromirror 111 on the substrate layer 140 have an overlapping portion, and the groove 143 between the flat plate driving electrode 141 and the vertical motion micromirror 111 forms an air gap 130 to constitute an electrostatic flat plate driver, and 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 a total 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 state 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 prior art 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 the MEMS optical phase shifter in the prior art can overcome many problems of other optical phase shifters, the optical phase modulation speed of the MEMS optical phase shifter 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 the optical phase shift and the phase shift speed are mutually restricted, resulting in the existing MEMS optical phase shifter technology being unable to meet the needs of applications such as vector optical phased arrays for high-speed modulation, large phase shift, and arraying of MEMS phase shifters.

[0058] The present invention integrates an electrostatic plate and a vertical comb dual driver and a displacement sensor in a single chip through the MEMS process. By setting an electrostatic comb driver and an electrostatic plate driver to form a dual drive structure of 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 greatly increasing the drive voltage, so that the optical path of the incident light wave signal can be quickly changed to achieve optical phase shifting; at the same time, by combining the closed-loop feedback control and the bidirectional electrostatic drive driving mode, 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, the phase shift amount and the phase shift bandwidth meet the requirements of the application fields such as the vector optical phased array for high speed, large phase shift amount and arraying of MEMS phase shifters; in addition, since high-speed phase shifting can be achieved in the MEMS optical phase shifter, it is conducive to the realization of low-cost, low-power and small-volume high-speed optical phase shifting equipment; in addition, by integrating the displacement sensor in the MEMS optical phase shifter, the displacement sensor 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 setting of the displacement sensor, further realizing low-cost, low-power and small-volume high-speed optical phase shifting equipment, which is conducive to 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 driving movable comb teeth 114 of the first planar area 110 and the driving fixed comb teeth 121 of the second planar area 120 to form a vertical comb tooth driver with a vertical height difference.

[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-tooth driver have the same height without vertical height difference; after the electrostatic flat-plate driver applies the DC bias voltage V0, the vertical motion micromirror 111 generates a height difference between the driving fixed comb teeth 121 and the driving movable comb teeth 114 in the first direction under the downward pulling force of the DC bias voltage V0 of the electrostatic flat-plate driver, forming "vertical comb teeth caused by bias", and a driving voltage is applied to the electrostatic comb-tooth driver to provide a driving force for pulling up the vertical motion micromirror 111; the accelerated motion of the vertical motion micromirror 111 downward along the first direction is driven by the electrostatic flat-plate driver, and the accelerated motion of the vertical motion micromirror 111 upward along the first direction is driven by the combined driving force of the rebound force of the elastic beam 112 and the static straight comb-tooth 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 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, and its surface is coated with an optical high-reflection film, which is a composite film composed of Ti with a thickness of 50 nm and Au with a thickness of 200 nm, and has a high reflectivity of up to 98.5% for an operating wavelength in the 1550 nm band; the movement of the vertical motion micromirror 111 is an off-plane vertical movement perpendicular to the MEMS chip, and its movement mode is a quasi-static vertical movement, and its movement stroke is 1550 nm, so that the optical phase shift amount of the high-speed MEMS optical phase shifter 100 is 4π radians.

[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 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 centrally symmetrically with the center point of the vertical motion micromirror 111 as the center of symmetry; the elastic beam 112 is a straight beam with a length of 300 μm, a width of 13 μm, and a height of 25 μm, which is symmetrically distributed around the vertical motion micromirror 111 and is made of the same silicon film as the vertical motion micromirror 111; a "chamfer" treatment is performed at the connection between the elastic beam 112 and the vertical motion micromirror 111 to reduce the maximum stress caused by the vertical motion, and at the same time, the dynamic deformation of the vertical motion micromirror 111 can also be reduced.

[0066] In this embodiment, Figure 2 As shown, the displacement sensor includes a sensing fixed comb tooth 151 and a sensing moving comb tooth 152, the sensing moving comb tooth 152 is fixedly connected to the vertical motion micromirror 111, the sensing fixed comb tooth 151 is fixedly connected to the second peripheral structure layer 122, and the sensing fixed comb teeth 151 and the sensing moving 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 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 respect to 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 a DC bias voltage V0, the heights of the movable comb teeth group and the fixed comb teeth group are consistent; after the electrostatic flat-plate driver applies a DC bias voltage V0, a ​​height difference is generated between the movable comb teeth group and the fixed comb teeth group, forming four groups of "bias-induced vertical comb teeth". Two groups of movable comb teeth and corresponding fixed comb teeth are electrostatically driven comb teeth groups consisting of driven fixed comb teeth 121 and driven movable comb teeth 114. The two groups of driven fixed comb teeth 121 are electrically interconnected. A driving voltage is applied to the 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 movable comb teeth and corresponding fixed comb teeth are capacitive sensing comb teeth groups consisting of sensing movable 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. The two groups of vertical comb teeth sensing capacitors are connected in parallel to each other to 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 packaging 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 symmetrically distributed 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 movable 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 movable 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, each group of dynamic comb teeth has 9 dynamic comb teeth, the total number of dynamic comb teeth is 36, each dynamic comb tooth has a length of 506 μm, an average width of 6.2 μm, a height of 25 μm, a rectangular shape, and is symmetrically distributed along the radial direction of the vertical motion micromirror 111, and is made of the same silicon film as the vertical motion micromirror 111.

[0074] In one embodiment, Figure 2As shown, the second plane region 120 includes 4 groups of second peripheral structure layers 122 and 4 groups of fixed comb teeth groups, the first plane region 110 includes 4 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 the air gap 130. Each group of fixed comb teeth groups has 9 fixed comb teeth, each fixed comb tooth has a length of 506 μm, a thinnest width of 1.7 μm, and a widest part of 47.08 μm, and the distribution shape of the fixed comb teeth group is a fan-shaped arc with a vertex angle of about 0.542° and a height of 25 μm. The gap angle between the fixed comb teeth is 1.146°, and the fixed comb teeth group and the vertical motion micromirror 111 are made of the same silicon film.

[0075] In one embodiment, the high-speed MEMS optical phase shifter 100 further includes a pad, which is 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 insulating grooves 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, the four groups of first peripheral structure layers 113 are bonded to the third peripheral structure layer 142 of the substrate layer 140 through gold-gold bonding, and two groups of first peripheral structure layers 113 also have ground pads 161, which are connected to the ground voltage source VGND. The first peripheral structure layers 113 are electrically isolated by etching insulating grooves 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 dynamic comb tooth group is connected to the vertical motion micromirror 111. The fixed comb tooth groups and the corresponding dynamic comb teeth are arranged alternately; each dynamic comb tooth is located in the middle of the fixed comb tooth gap, and the average spacing between the dynamic comb teeth and adjacent fixed comb teeth is 4 μm, and is 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 micrometers.

[0084] In one embodiment, Figure 3 As shown, the 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 adopts a dual power supply drive composed of a DC bias power supply V0 and a programmable analog power supply V1 to realize 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 driving electrode 141 constitute an electrostatic flat plate driver, and the flat plate electrode pad 162 is connected to a dual power supply drive composed of 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 polarities) to achieve downward electrostatic driving 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 1.55μm corresponding to the maximum optical phase shift of the high-speed MEMS optical phase shifter 100, that is, 0.775μm. In this embodiment, d0=0.85μm.

[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 sets the displacement of the vertical motion micromirror 111 driven by the driver to be greater than half of the maximum optical phase shift that the vertical motion micromirror 111 can perform in the high-speed MEMS optical phase shifter 100, thereby ensuring that the two drivers can each drive the vertical motion micromirror 111 to shift to half of the maximum optical phase shift, and making the total displacement of the vertical motion micromirror 111 driven by the two drivers greater than the maximum optical phase shift allowed in the high-speed MEMS optical phase shifter 100, thereby making full use of the shiftable space in the high-speed MEMS optical phase shifter 100 and maximizing the range of the phase shift that can be achieved by the high-speed MEMS optical phase shifter 100. Specifically, the maximum optical phase shift that the vertical motion micromirror 111 can perform in the high-speed MEMS optical phase shifter 100 corresponds to the maximum distance that the vertical motion micromirror 111 can move in the air gap 130 in the first direction, which is approximately the difference between the thickness of the air gap 130 in the first direction and the thickness of the vertical motion 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 working bandwidth of the high-speed MEMS optical phase shifter 100, thereby ensuring that the output signal of the displacement sensor can timely feedback the real-time displacement of the high-speed MEMS optical phase shifter 100, so as to realize high-speed real-time feedback control of the driver, thereby ensuring the realization of the working 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 of a PID (Proportion Integral Differential) algorithm.

[0093] The present invention uses a PID algorithm to feedback control the driving state of the high-speed MEMS optical phase shifter 100, which can further improve the control accuracy and speed of the phase shift amount to ensure high speed and high precision of the optical phase shift.

[0094] In one embodiment, a PID closed-loop feedback control is used to control the vertical motion micromirror 111 to move vertically in a first direction and generate an optical phase shift. In the downward acceleration movement of the vertical motion micromirror 111 in the first direction, an electrostatic flat plate driver and the rebound force (upward) of the elastic beam 112 are used to provide acceleration; in the upward acceleration movement of the vertical motion micromirror 111, the upward driving force of the electrostatic comb driver is used to provide upward acceleration. At the same time, the rebound force (upward) of the elastic beam 112 exists as the driving force for the upward acceleration, and the downward driving force of the electrostatic flat plate driver can exist as a driving resistance for controlling the upward acceleration. The displacement sensor composed of the sensing fixed comb teeth 151 and the sensing moving comb teeth 152 provides a vertical displacement signal of the vertical motion micromirror 111 to the feedback control chip 609 in the PID closed-loop feedback control. Under the feedback control of the feedback control chip 609 on the electrostatic comb driver and the electrostatic flat plate driver, feedback control of the vertical displacement of the vertical motion micromirror 111, i.e., the optical phase shift, is realized. In this embodiment, the operating bandwidth of the displacement sensor is 500 kHz, which is 5 times the operating bandwidth of the high-speed MEMS optical phase shifter 100 , which is 100 kHz.

[0095] Embodiment 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 other features as the high-speed MEMS optical phase shifter 100 in Embodiment 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 71 is a top view of the second plane area 120 of the high-speed MEMS optical phase shifter 100, wherein the displacement sensor comprises an annular electrode 251 and the vertical motion micromirror 111, wherein the annular electrode 251 is fixed to the bottom of the groove 143 and surrounds the flat plate driving electrode 141, and there is electrical isolation between the annular electrode 251 and the flat plate driving electrode 141; the annular electrode 251 has an overlapping portion with the projection of the vertical motion micromirror 111 and / or 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 / or the elastic beam 112 forms an air gap 130 to constitute the displacement sensor.

[0098] The present invention arranges the annular electrode 251 around the flat-plate driving electrode 141, so that the annular electrode 251 can be prepared simultaneously during the patterning process of preparing the flat-plate driving electrode 141, thereby ensuring that the preparation efficiency of the integrated displacement sensor does not reduce the preparation efficiency of the high-speed MEMS optical phase shifter 100, and at the same time, the comb tooth group can be driven only as an electrostatic comb tooth driver without separating part of the comb tooth group for displacement sensing, thereby further improving the driving force, thereby further improving 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 as required and are within the protection scope 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 projections of the annular electrode 251, the vertical motion micromirror 111, and the elastic beam 112 on the substrate layer 140 all have overlapping parts, 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, Figure 5 As shown, the annular electrode 251 is also electrically connected to the corresponding annular electrode pad 252 to lead out the electrical connection to the required components.

[0104] Embodiment 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 other features as the high-speed MEMS optical phase shifter 100 in Embodiment 1, except that:

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

[0107] The present invention forms a Wheatstone bridge circuit by setting a strain varistor 351 and a reference resistor 352. When the elastic beam 112 is strained with the displacement of the vertically moving micromirror 111, the resistance value of the strain varistor 351 will change. When the input electrical signal 355 of the Wheatstone bridge circuit remains unchanged, the changed resistance value of the strain varistor 351 will cause the output electrical signal 356 of the Wheatstone bridge circuit to change. By calculating the change amount of the output electrical signal 356, the change amount of the resistance value of the strain varistor 351 can be obtained. The stress change of 12 is linearly related to the displacement of the vertical motion micromirror 111, so that 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 varistor 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, lightweight and low power consumption of the high-speed MEMS optical phase shifter 100.

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

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

[0110] In one embodiment, the strain varistor 351 and the reference resistor 352 are connected via a metal lead 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 varistor 351 and the reference resistor 352 may be adjusted according to the needs of the Wheatstone bridge circuit.

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

[0113] Embodiment 4:

[0114] This embodiment provides a high-speed MEMS optical phase shifter array 400, which includes n high-speed MEMS optical phase shifters 100 described in any one of Embodiments 1-3 arranged in an array, 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 configuring the high-speed MEMS optical phase shifters 100 in Examples 1-3, which is helpful to meet the application requirements of optical devices requiring 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, Fig.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 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, Fig.11 As shown, the four high-speed MEMS optical phase shifters 100 are arranged as 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 according to requirements.

[0122] Embodiment 5:

[0123] This embodiment provides a high-speed MEMS optical phase shifter packaging structure 600, wherein the high-speed MEMS optical phase shifter packaging structure 600 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 Embodiments 4;

[0124] like Fig.12 As shown, the high-speed MEMS optical phase shifter packaging structure 600 also 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 flat plate driver of the high-speed MEMS optical phase shifter 100, and is used to drive the electrostatic comb driver and the electrostatic flat plate driver of the high-speed MEMS optical phase shifter 100 (provide driving power for the electrostatic comb driver and the electrostatic flat 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 flat 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 sensor detection circuit chip 608, and the input / output connector 604, and is used to receive the sensing electrical signal of the sensor 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 Embodiment 1-2 is a capacitance detection chip, and the sensing detection circuit chip 608 electrically connected to the displacement sensor in Embodiment 3 is a resistance detection chip.

[0127] In one embodiment, Fig.12As shown, the high-speed MEMS optical phase shifter packaging structure 600 also 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 flat plate driver, the sensor detection circuit chip 608 for processing the sensing electric signal of the displacement sensor, and the feedback control chip 609 for receiving the sensing electric signal and the phase control information transmitted by the external control system and calculating the vertical displacement of the vertical motion micromirror 111 and providing it to the control electric drive chip 607 to realize the electrostatic drive, and is connected to the input / output connector 604 for transmitting the electric signal;

[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 plate 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 or / and the high-speed MEMS optical phase shifter 100 to the periphery of the high-speed MEMS optical phase shifter array 400 chip, so as to facilitate subsequent packaging and wiring.

[0132] In one embodiment, Fig.12 As shown, the packaging cavity 606 of the packaging structure is a cavity formed by wrapping an upper cover plate 601 and a packaging shell 602, and the upper cover plate 601 and the packaging shell 602 are made of aluminum alloy; the packaging structure includes a high-speed MEMS optical phase shifter chip 500 composed of a high-speed MEMS optical phase shifter 100 or / and a high-speed MEMS optical phase shifter array 400; on the bottom plate of the packaging 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 sequence 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 flat cable 611, and 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 wiring under the PCB board 610. The size of the PCB board 610 is 25mm*12mm. Fig.12 As shown, the MEMS optical phase shifter array chip is adhered to the upper surface of the PCB board 610 through the thermal conductive adhesive 613, and is electrically connected and transmits signals to the PCB board 610 through the bonding wires 614; the input / output connector 604 is flip-chip welded on the upper surface of the PCB board 610.

[0135] In one embodiment, Fig.12 As shown, a dual-fiber collimator 605 is mounted on the upper cover plate 601, corresponding to the vertical motion micromirror 111 in the high-speed MEMS optical phase shifter 100. The upper cover plate 601 is used to carry the dual-fiber collimator 605, and is made of the same material as the package shell 602. A hole corresponding to the vertical motion micromirror 111 is made thereon, 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 optical fiber 615 provides the high-speed MEMS optical phase shifter 100 with an optical signal input from the outside, and the rod lens C-Lens 617 collimates the optical signal input from the input optical fiber 615; the dual-fiber collimator is precisely adjusted by the precision optical adjustment frame, so that the input optical signal is reflected by the vertical motion micromirror 111, and the optical signal insertion loss emitted to the output optical fiber 616 is minimized, and the insertion loss is generally within the range of 0.2-0.3dB, and the output optical fiber 616 outputs the output optical signal after the phase shift by the vertical motion micromirror 111. The specific installation method is: insert the pre-made dual-fiber collimator 605 into the corresponding hole, and fix it on the upper cover plate 601 with adhesive after precise adjustment and alignment. Specifically, it is first quickly fixed by ultraviolet glue, and then strengthened by thermal curing agent; in the high-speed MEMS optical phase shifter array 400 chip, each dual-fiber collimator 605 needs to be assembled one by one with the corresponding high-speed MEMS optical phase shifter 100 in sequence.

[0136] In one embodiment, Fig.12As shown, when the high-speed MEMS optical phase shifter chip 500 in the high-speed MEMS optical phase shifter packaging structure 600 includes a 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, and the dual-fiber collimator 605 array includes dual-fiber collimators 605 corresponding to each high-speed MEMS optical phase shifter 100, and 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] Embodiment 6:

[0138] This embodiment provides an optical device, which includes a high-speed MEMS optical phase shifter device composed 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 that require 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 and its array, packaging structure and optical device of the present invention can respectively drive the displacement of the vertical motion micromirror in two opposite directions through the dual-drive structure formed by the electrostatic comb teeth and the electrostatic plate, thereby realizing high-speed optical phase shifting under a simple structure; at the same time, through the cooperation of closed-loop feedback control and the dual-drive structure, the control accuracy of the phase shift amount of the phase shifter is improved; in addition, high-speed phase shifting is realized by the MEMS phase shifter, which is conducive to realizing a low-cost, low-power, and small-volume high-speed phase shifting device; finally, by integrating a displacement sensor in the MEMS phase shifter, a low-cost, low-power, and small-volume high-speed phase shifting device is further realized.

[0142] Therefore, the present invention effectively overcomes various shortcomings in 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 familiar with 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still 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 comprises: a silicon film, a substrate layer and a displacement sensor, the silicon film comprises a first plane region and a second plane region, the first plane region, the second plane region and the substrate layer are all perpendicular to a first direction; The first plane area includes a vertical motion micromirror, an elastic beam, a driving comb tooth and a first peripheral structure layer, 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 through the elastic beam, and the driving comb tooth is only fixedly connected to the vertical motion micromirror; the second plane area includes driving fixed comb teeth and a second peripheral structure layer, the driving fixed comb teeth are fixedly connected to the second peripheral structure layer; the driving fixed comb teeth and the driving movable comb teeth are arranged alternately 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, 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, 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 a total structure layer; The displacement sensor is used to sense the displacement of the vertical motion 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 vertical motion micromirror along the first direction.

2. The high-speed MEMS optical phase shifter according to claim 1, characterized in that: 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 corresponding to each other to form the displacement sensor.

3. The high-speed MEMS optical phase shifter according to claim 1, characterized in that: The displacement sensor comprises a ring-shaped electrode and the vertical motion micromirror, wherein the ring-shaped electrode is fixed at the bottom of the groove and surrounds the flat-plate driving electrode, and 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, and 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, characterized in that: The displacement sensor includes a strain varistor and a reference resistor, wherein the strain varistor is located on the elastic beam, and the reference resistor is located on the overall structural layer. The strain varistor 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, characterized in that: 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, characterized in that: 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, 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, characterized in that: 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 flat plate driver of the high-speed MEMS optical phase shifter, and is used to drive the electrostatic comb driver and the electrostatic flat 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, and calculate the driving signal required for the vertical motion micromirror to perform vertical displacement and provide it to the electric drive chip, so as 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 comprises a high-speed MEMS optical phase shifter device consisting of the high-speed MEMS optical phase shifter described in any one of claims 1-6, the high-speed MEMS optical phase shifter array described in any one of claims 7-8, or / and the high-speed MEMS optical phase shifter packaging structure described in claim 9.

Images