Amplitude self-stabilizing electrostatic driving MEMS micromirror chip

Abstract

The invention relates to an amplitude self-stabilizing electrostatic driving MEMS (Micro Electro Mechanical System) micromirror chip, which comprises an outer frame, a reflecting mirror connected to the outer frame and capable of rotating, at least one adjustable capacitor arranged on the outer frame, at least one driving capacitor group connected in series with the adjustable capacitor, and at least one waveguide arranged at the edge of the reflecting mirror, the rotating shafts are used for connecting the outer frame with the reflecting mirror; through the cooperation of the driving capacitor group and other parts, the functions of displacement sensing of the reflector and self-adaptive adjustment of a control signal are realized, the closed-loop feedback control of the reflector can be realized only by inputting a fixed voltage signal into the driving circuit outside the chip, and the driving circuit has the characteristics of high integration level, compact structure and low requirement on the driving circuit, and is suitable for popularization and application. And the method is suitable for high-integration compact equipment.

Description

Technical Field

[0001] This invention relates to the field of MEMS micromirror chip technology, and in particular to an amplitude-self-stabilized electrostatically driven MEMS micromirror chip. Background Technology

[0002] MEMS (Micromirror Models) chips are chips that integrate micromechanical structures and circuits, fabricated using semiconductor processing technology. They mainly consist of a mirror, a driving element, and corresponding auxiliary structures. The mirror undergoes a specific displacement under the action of the driving element; this displacement can be used to change the reflection direction of a light beam incident on the mirror surface. MEMS chips can change the reflection direction of incident light beams and are widely used in projection, optical communication, optical computing, 3D imaging, and spectrometers. Electrostatic MEMS micromirrors use electrostatic driving technology to control the mirror. They are compact, simple to manufacture, and have low hysteresis, making them widely adopted. Control of electrostatic MEMS micromirrors is divided into open-loop and closed-loop types. Open-loop control is sufficient for applications where mirror displacement accuracy is not high or in switching applications; however, closed-loop control is required in fields such as projection and 3D imaging where mirror displacement is critical. Currently, closed-loop feedback methods for electrostatic MEMS micromirrors include external feedback and chip-integrated feedback. External feedback uses external components such as photodetectors to detect mirror displacement and provide feedback. This method is easy to implement, but involves many components, a complex system, and high installation difficulty. Chip-integrated feedback involves designing feedback elements within a chip to directly sense the displacement of the reflector and achieve feedback. This method is compact and the system is simple. Chip-integrated feedback mainly includes capacitive feedback, piezoresistive feedback, and piezoelectric feedback. For example, patent application CN110333598A discloses a method and circuit for obtaining the capacitive feedback signal of a micro-torsion mirror. This scheme uses capacitive feedback to sense the angle of the micro-torsion mirror, and improves the stability of the capacitive feedback signal through circuit design, making the circuit simpler. However, this type of feedback integrates the displacement sensing element into the micromirror chip. The obtained angular displacement signal still needs to be transmitted to the control circuit outside the micromirror chip for filtering, amplification, and other processing. Then, the processed angular displacement signal is fed back to the control signal to achieve closed-loop control of the reflector. The control circuit is still complex, difficult to implement, and large in size, making it difficult to apply in highly integrated and compact devices. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention aims to provide an amplitude-self-stabilized electrostatic drive MEMS micromirror chip. Through the cooperation of the drive capacitor bank and other components, the chip realizes the displacement sensing and adaptive adjustment function of the control signal of the reflector. The external drive circuit only needs to input a fixed voltage signal to realize the closed-loop feedback control of the reflector. It has the characteristics of high integration, compact structure, and low requirements for drive circuit, and is suitable for highly integrated compact devices.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A self-stabilized electrostatically driven MEMS micromirror chip includes an outer frame 500; a rotatable mirror 100 connected to the outer frame 500; at least one adjustable capacitor 200 disposed on the outer frame 500; at least one set of driving capacitors 400 connected in series with the adjustable capacitor 200; at least one waveguide 102 disposed on the edge of the mirror 100; and one or two pairs of rotating shafts 300 connecting the outer frame 500 and the mirror 100.

[0006] The adjustable capacitor 200 includes a positive electrode 201, a negative electrode 203, and a dielectric block 202. The positive electrode 201 and the negative electrode 203 are arranged opposite to each other, and the dielectric block 202 is arranged in the region between the positive electrode 201 and the negative electrode 203.

[0007] The reflector 100 includes a mirror body 101, and a reflective layer 103 is disposed on the upper surface of the mirror body 101; at least one waveguide 102 is disposed on the edge of the mirror body 101, and the reflective layer 103 covers most of the surface area of ​​the mirror body 101, but does not cover the waveguide 102.

[0008] When there is a pair of rotating shafts, the two ends of the reflector 100 are connected to the outer frame 500 through the rotating shaft 300. At least one adjustable capacitor 200 is provided on the outer frame 500 and connected in series with the positive terminal 401 and the negative terminal 402 of the driving capacitor group 400. The positive terminal 401 of the driving capacitor group 400 is fixed on the reflector 100 or its rotating shaft 300, and the negative terminal 402 is fixed on the outer frame 500; or the negative terminal 402 is fixed on the reflector 100 or its rotating shaft 300, and the positive terminal 401 is fixed on the outer frame 500.

[0009] When there are two pairs of rotating shafts, it also includes a movable frame 600. The two ends of the reflector 100 are connected to the movable frame 600 through the rotating shaft 300, and the two ends of the movable frame 600 are connected to the outer frame 500 through the second rotating shaft 310. The rotating shaft 300 and the second rotating shaft 310 are perpendicular to each other. It also includes at least two sets of capacitor groups for providing electrostatic driving force, namely the driving capacitor group 400 and the second driving capacitor group 410.

[0010] The driving capacitor group 400 includes a positive electrode 401 and a negative electrode 402. The positive electrode 401 is fixed on the reflector 100 or its rotating shaft 300, and the negative electrode 402 is fixed on the movable frame 600; or the negative electrode 402 is fixed on the reflector 100 or its rotating shaft 300, and the positive electrode 401 is fixed on the movable frame 600.

[0011] The second driving capacitor group 410 includes a second positive electrode 411 and a second negative electrode 412. The second positive electrode 411 is fixed to the movable frame 600 or the second rotating shaft 310 connected thereto, and the second negative electrode 412 is fixed to the outer frame 500; or the second negative electrode 412 is fixed to the movable frame 600 or the second rotating shaft 310 connected thereto, and the second positive electrode 411 is fixed to the outer frame 500.

[0012] At least one adjustable capacitor 200 is provided on each of the movable frame 600 and the outer frame 500, and each group of driving capacitors 400 is connected in series with at least one adjustable capacitor 200.

[0013] When there are two pairs of rotating shafts, there are at least two waveguides 102, one of which is located at the edge of the mirror body 101; the other waveguide is also located at the edge of the mirror body 101 and is located in the area where the movable frame 600, the mirror body 101 and the first rotating shaft 300 are connected.

[0014] The driving capacitor group 400 is a parallel plate capacitor pair structure or a comb-tooth capacitor group structure with staggered arrangement.

[0015] When the driving capacitor group 400 is a parallel plate capacitor pair structure, it includes at least one positive electrode 401 and at least one negative electrode 402; the positive and negative electrodes are arranged opposite each other, and their projections perpendicular to the opposite surfaces have overlapping areas, and the distance between the positive and negative electrodes is not zero; the positive electrode 401 is disposed on the lower surface of the mirror body 101, and the negative electrode 402 is disposed below the positive electrode plate 201 and connected to the outer frame 500; the positive electrode 401 is connected to the negative electrode plate 203 of the adjustable capacitor 200, the positive electrode of the external power supply is connected to the positive electrode plate 201 of the adjustable capacitor 200, and the negative electrode of the external power supply is connected to the negative electrode 402 of the driving capacitor group 400; a dielectric block 202 is disposed between the positive electrode plate 201 and the negative electrode plate 203, which together constitute the first adjustable capacitor 200.

[0016] When the driving capacitor group 400 is a comb-tooth capacitor group structure, it has at least one set of positive comb teeth and at least one set of negative comb teeth, and only one pair of rotating shafts 300; specifically: the driving capacitor group 400 includes a positive electrode 401 and a negative electrode 402, and the comb teeth of the positive electrode 401 and the negative electrode 402 are arranged in a crisscross pattern; all the positive comb teeth 401 are connected to the negative electrode plate 203 of the adjustable capacitor 200, all the comb teeth of the negative electrode 402 are connected to the negative electrode of the external power supply, and the positive electrode of the external power supply is connected to the positive electrode plate 201 of the adjustable capacitor 200; a dielectric block 202 is provided between the positive electrode plate 201 and the negative electrode plate 203, which together constitute the first adjustable capacitor 200.

[0017] When the driving capacitor 400 has a comb-tooth structure and includes two pairs of rotating shafts, it also includes a movable frame 600. The two outer ends of the movable frame 600 are connected to the outer frame 500 through the second rotating shaft 310. The movable frame 600 is connected to both ends of the reflector 100 through the rotating shaft 300. The rotating shaft 300 and the second rotating shaft 310 are perpendicular to each other. A waveguide 102 is provided on the mirror body 101. A second waveguide 112 is provided on the mirror body 101, the first rotating shaft 300, and the movable frame 600. An adjustable capacitor 200 is provided on the movable frame 600, and a second adjustable capacitor 210 is provided on the outer frame 500. The light emitted from the waveguide 102 illuminates the adjustable capacitor 200. The light emitted from the second waveguide 112 illuminates the second adjustable capacitor 210.

[0018] The dielectric block 202 is made of a material with an adjustable dielectric constant. The dielectric block 202 is composed of two or more materials, wherein the dielectric constant of at least one material increases with increasing optical power and continues to increase with increasing irradiation time; the dielectric constant of at least one material decreases with increasing optical power and continues to decrease with increasing irradiation time.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. A driving capacitor bank, a waveguide, and an adjustable capacitor are integrated into the MEMS galvanometer chip. The driving capacitor bank and the adjustable capacitor bank are connected in series to form a capacitive voltage divider circuit. The waveguide introduces a portion of the incident laser light into the dielectric block of the adjustable capacitor. The dielectric constant of this dielectric block changes under different light intensities, leading to a change in the capacitance of the adjustable capacitor, which in turn causes a change in the voltage across the driving capacitor bank and the adjustable capacitor. This method achieves feedback control of the galvanometer rotation angle.

[0021] 2. This feedback control is achieved entirely through the components inside the galvanometer chip. The external circuit only needs to provide a stable DC voltage input, without the need for a feedback control circuit, which greatly reduces the requirements and difficulty of the external circuit.

[0022] In summary, the waveguide and adjustable capacitor design of this invention eliminates the need for external feedback, and the driving circuit only needs to provide a fixed voltage to achieve closed-loop feedback control. The closed-loop feedback system inside the chip has fewer components, fewer signal conversion and transmission times, faster response speed, higher reliability, lower chip manufacturing cost, and a compact chip and circuit module structure, making it suitable for highly integrated miniaturized devices. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a self-stabilizing MEMS micromirror chip (with a set of driving capacitors in a comb-like structure and a set of rotating shafts).

[0024] Figure 2 This is a schematic diagram of a self-stabilizing electrostatically driven MEMS micromirror chip system.

[0025] Figure 3 This is a schematic diagram showing the relationship between the dielectric constant of the dielectric block and the rotation angle of the reflector.

[0026] Figure 4 This is a schematic diagram of the working process of a self-stabilizing MEMS micromirror chip.

[0027] Figure 5 This is a schematic diagram of the second structure of a self-stabilizing MEMS micromirror chip (the driving capacitor group is a parallel plate capacitor, and there is a set of rotating shafts).

[0028] Figure 6 This is a schematic diagram of the third structure of a self-stabilizing MEMS micromirror chip (with two sets of driving capacitors, a comb-tooth structure, and two sets of rotating shafts).

[0029] In the picture:

[0030] 100: Mirror, 101: Mirror body, 102: Waveguide, 103: Reflecting layer;

[0031] 200: Adjustable capacitor, 201: Positive electrode, 202: Dielectric block, 203: Negative electrode, 210: Second adjustable capacitor, 211: Second positive electrode, 212: Second dielectric block, 213: Second negative electrode;

[0032] 300: pivot, 310: second pivot;

[0033] 400: Drive capacitor bank, 401: Positive terminal, 402: Negative terminal, 410: Second drive capacitor bank, 411: Second positive terminal, 412: Second negative terminal;

[0034] 500: Outer frame;

[0035] 600: Movable frame. Detailed Implementation

[0036] The structural and working principles of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] like Figure 1 A structure for an amplitude-stabilized electrostatically driven MEMS micromirror chip includes a reflector 100, with both ends of the reflector 100 connected to an outer frame 500 via a pivot 300. The reflector can rotate around the pivot. A pair of adjustable capacitors 200 are disposed on the outer frame 500 and connected in series with a driving capacitor group 400. The driving capacitor group 400 has an alternating comb structure, including comb teeth as positive electrodes 401 and comb teeth as negative electrodes 402. The positive electrodes 401 are fixedly connected to the pivot 300, and the negative electrodes 402 are fixedly connected to the outer frame 500. All comb teeth of the positive electrodes 401 are connected to the negative electrode 203 of the adjustable capacitors 200, and all comb teeth of the negative electrodes 402 are connected to the negative terminal of an external power supply. The positive terminal of the external power supply is connected to the positive electrode 201 of the adjustable capacitors 200.

[0039] The reflector 100 includes a mirror body 101, a reflective layer 103 is disposed on the upper surface of the mirror body 101, and a waveguide 102 is disposed on the edge of the mirror body 101, the reflective layer 103 does not cover the waveguide 102.

[0040] The adjustable capacitor 200 includes a positive electrode 201, a negative electrode 203, and a dielectric block 202 disposed between the positive electrode 201 and the negative electrode 203.

[0041] The waveguide 102 is disposed at the edge of the mirror 101. The reflective layer 103 covers most of the surface area of ​​the mirror 101, but does not cover the waveguide 102. When a light beam shines on the mirror, most of the incident light is reflected by the reflective layer 103. The light beam that shines on the waveguide 102 is redirected and propagates along a direction parallel to the surface of the mirror. It exits from the side of the waveguide 102 and shines on the outer frame 500, and then on the dielectric block 202 of the adjustable capacitor 200.

[0042] The dielectric block 202 is made of a material with an adjustable dielectric constant, which changes under the influence of light. The dielectric block 202 is composed of two materials: the dielectric constant of material A increases with increasing light power and, within a certain range, continues to increase with increasing irradiation time; the dielectric constant of material B decreases with increasing light power and, within a certain range, continues to decrease with increasing irradiation time.

[0043] Since the waveguide 102 is located at the edge of the mirror 101, its position changes as the mirror 103 rotates. With a fixed incident light power, the light power emitted from the waveguide 102 to the dielectric block 202 changes with the rotation angle of the mirror.

[0044] The working principle of this embodiment is as follows:

[0045] like Figure 2 When the micromirror chip is working, an external power supply is applied to the circuit connecting the driving capacitor bank 400 and the adjustable capacitor 200 in series. The driving capacitor bank 400 generates an electrostatic force Fes due to the voltage across it, causing the reflector 100 to rotate around the axis 300. A laser beam is incident on the surface of the reflector 100 at a specific angle and is mostly reflected. The light rays hitting the waveguide 102 are redirected and propagate parallel to the mirror surface, eventually illuminating the dielectric block 202 of the adjustable capacitor. The dielectric block 202 is fixed in position, but the waveguide 102 rotates with the reflector 100. Therefore, the area where the light-emitting surface of the waveguide 102 overlaps with the dielectric block 202 changes with the rotation angle. The larger the area where the light-emitting surface of the waveguide 102 overlaps with the dielectric block 202, the greater the optical power received by the dielectric block 202, and vice versa.

[0046] Still as Figure 2 The adjustable capacitor has a capacitance of Ct, and the driving capacitor bank has a capacitance of Cd. The adjustable capacitor and the driving capacitor bank are connected in series, and the total voltage applied across this series circuit is U. Then we have...

[0047] U = U d +U d

[0048] in

[0049]

[0050] The mirror 100 is subjected to electrostatic driving force Fes generated by Ud during rotation, as well as damping force and reaction force generated by shaft deformation. For ease of analysis, the various reaction forces, including damping force, are collectively referred to as reaction force Frep.

[0051] The entire self-stabilizing process is as follows Figure 3 , Figure 4 As shown.

[0052] When Fes = Frep, the reflector 100 rotates at a defined maximum angle, considered a stable state. At this point, the maximum angle is θc, and the optical power emitted from the waveguide 102 to the dielectric block of the adjustable capacitor 200 is Pc. At this time, the rate of increase of the dielectric constant of material A in the dielectric block 202 is equal to the rate of decrease of the dielectric constant of material B, and the total dielectric constant of the dielectric block 202 remains fixed. Therefore, the capacitance value of the adjustable capacitor remains fixed at Cc. When the reaction force of the reflector 100 decreases due to factors such as ambient temperature, but the driving force Ud remains unchanged, the maximum angle increases to θc + δθ. Since the light intensity distribution emitted from the waveguide 102 is Gaussian or quasi-Gaussian (strong at the center, gradually weakening towards the sides), and the waveguide 102 is located at the edge of the mirror body 101 of the reflector 100, when the angle of the reflector 100 increases, the angle of the waveguide 102 also increases, and the optical power emitted to the dielectric block 202 of the adjustable capacitor 200 decreases. Then the rate of increase of the dielectric constant of A is less than the rate of decrease of the dielectric constant of B, such as Figure 3 As the total dielectric constant of the dielectric block decreases, the capacitance of the adjustable capacitor continues to decrease, the voltage across the adjustable capacitor continues to increase, the voltage across the driving capacitor bank continues to decrease, and the electrostatic force Fes on the reflector continues to decrease until the maximum rotation angle of the reflector returns to θc. At this point, the rate of increase of the dielectric constant of A is equal to the rate of decrease of the dielectric constant of B. The total dielectric constant of the dielectric block no longer changes, and the capacitance of the adjustable capacitor Ct also no longer changes (from the initial Cc to Cc-δC and remains stable). Then, the voltage across the driving capacitor remains fixed, and the driving force Fes and the reaction force Frep reach a new stable state of equality. The reflector returns to the maximum rotation angle θc and rotates stably.

[0053] When the maximum rotation angle of the reflector decreases from θc to θc-δθ, the reverse process of the above change occurs, and the maximum rotation angle of the reflector also returns to θc.

[0054] Example 2

[0055] like Figure 5 Another structure of an amplitude-self-stabilized electrostatically driven MEMS micromirror chip includes a reflector 100 and an outer frame 500, wherein the reflector 100 and the outer frame 500 are connected by a pivot 300.

[0056] The reflector 100 includes a mirror body 101, and a reflective layer 103 is disposed on the upper surface of the mirror body 101; a waveguide 102 is disposed on the edge of the mirror body 101, and the reflective layer 103 does not cover the waveguide 102.

[0057] The reflector 100 has a positive electrode 401 on the lower surface of its mirror body 101, and its outer frame is a groove-shaped structure with a negative electrode 402 at the bottom. The positive electrode 401 and negative electrode 402 together constitute the driving capacitor 400. The positive electrode 401 is connected to the negative electrode 203 of the adjustable capacitor 200. The positive terminal of the external power supply is connected to the positive electrode 201 of the adjustable capacitor 200, and the negative terminal of the external power supply is connected to the negative electrode 402 of the driving capacitor group 400. When the external power supply is turned on, a voltage is generated between the positive and negative plates of the driving capacitor group, thereby generating an electrostatic force that drives the reflector to rotate around its axis. A dielectric block 202 is disposed between the positive electrode 201 and the negative electrode 203 of the adjustable capacitor 200, together forming the adjustable capacitor 200.

[0058] The working principle and process of this embodiment are the same as those of embodiment 1. The difference lies in the structural form of the driving capacitor group 400: that is, the driving capacitor group of embodiment 1 is a comb-shaped capacitor group with intersecting arrangement, while the driving capacitor group of embodiment 2 is a plate capacitor structure with the positive and negative terminals arranged opposite each other. The projections of the two terminals perpendicular to the opposite plane have overlapping areas, and the distance between the positive and negative terminals is not zero.

[0059] Example 3

[0060] like Figure 6 A third structure for an amplitude-self-stabilized electrostatically driven MEMS micromirror chip includes a mirror body 100 and a movable frame 600; the mirror body 100 and the movable frame 600 are connected by a pair of rotating shafts 300; the movable frame is connected to the outer frame 500 by a pair of second rotating shafts 310. The rotating shafts 300 and the second rotating shafts 310 are perpendicular to each other.

[0061] The reflector 100 includes a mirror body 101, and a reflective layer 103 is disposed on the upper surface of the mirror body 101; a waveguide 102 is disposed on the edge of the mirror body 101, and the reflective layer 103 does not cover the waveguide 102.

[0062] It also includes a second waveguide 112, which is disposed on one of the mirror body 101, the movable frame 600 and the rotating shaft 300 connecting the two.

[0063] It also includes a driving capacitor group 400 and a second driving capacitor group 410. Both driving capacitor groups have a comb-tooth structure. When there are two or more driving capacitor groups 400, for the first driving capacitor group 400, all the comb teeth of its positive terminals 401 are connected to the negative terminal 203 of the first adjustable capacitor 200, and all the comb teeth of its negative terminals 402 are connected to the negative terminal of the external power supply; the positive terminal 201 of the first adjustable capacitor 200 is connected to the positive terminal of the external power supply. For the second driving capacitor group 410, all the comb teeth of its second positive terminals 411 are connected to the second negative terminal 213 of the second adjustable capacitor 210, and all the comb teeth of its second negative terminals 411 are connected to the negative terminal of the external power supply; the second positive terminal 211 of the second adjustable capacitor 210 is connected to the positive terminal of the external power supply.

[0064] An adjustable capacitor 200 is provided on the movable frame 600, and a second adjustable capacitor 210 is provided on the outer frame 500. Light emitted from the first waveguide 102 illuminates the adjustable capacitor 200; light emitted from the second waveguide 112 illuminates the second adjustable capacitor 210.

[0065] Working principle of this embodiment:

[0066] The basic principle is the same as in Embodiment 1. The difference is that when the micromirror chip is working, an external power supply is applied to both ends of the circuit in series between the driving capacitor group 400 and the adjustable capacitor 200, and to both ends of the circuit in series between the second driving capacitor group 410 and the second adjustable capacitor 210. The reflector rotates around the axis of rotation under the drive of the driving capacitor group; at the same time, the reflector 100, together with the movable frame 600, rotates around the second axis of rotation 310 under the drive of the second driving capacitor group.

[0067] It should be noted that the driving capacitor group 400 and the second driving capacitor group can be driven by independent external power supplies, that is, they can work independently; the reflector 100 can rotate around the pivot 300 alone, or the reflector together with the movable frame 600 can rotate around the pivot 310 alone, or the reflector 100 can rotate around the pivot 300 while the reflector together with the movable frame 600 rotates around the pivot 310.

[0068] Waveguide 102 and adjustable capacitor 200 together provide angle feedback for the rotation of mirror 100 around axis 300; second waveguide 112 and second adjustable capacitor 210 together provide angle feedback for the rotation of mirror 100 together with movable frame 600 around axis 310. That is, the mirror in this embodiment has two rotation directions, which can realize closed-loop control of rotation in two directions.

Claims

1. An amplitude-self-stabilized electrostatically driven MEMS micromirror chip, comprising an outer frame (500); a rotatable reflector (100) connected to the outer frame (500); characterized in that, At least one adjustable capacitor (200) is disposed on the outer frame (500); at least one set of driving capacitors (400) connected in series with the adjustable capacitor (200); at least one waveguide (102) disposed on the edge of the reflector (100); and one or two pairs of rotating shafts (300) connecting the outer frame (500) and the reflector (100).

2. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, The adjustable capacitor (200) includes a positive electrode (201), a negative electrode (203), and a dielectric block (202). The positive electrode (201) and the negative electrode (203) are arranged opposite to each other, and the dielectric block (202) is arranged in the region between the positive electrode (201) and the negative electrode (203).

3. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, The reflector (100) includes a mirror body (101), and a reflective layer (103) is provided on the upper surface of the mirror body (101). At least one waveguide (102) is provided on the edge of the mirror body (101), and the reflective layer (103) covers most of the surface area of ​​the mirror body (101), but does not cover the waveguide (102).

4. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, When there is a pair of rotating shafts, the two ends of the reflector (100) are connected to the outer frame (500) through the rotating shaft (300). At least one adjustable capacitor (200) is provided on the outer frame (500) and is connected in series with the positive terminal (401) and negative terminal (402) of the driving capacitor group (400). The positive terminal (401) of the driving capacitor group (400) is fixed on the reflector (100) or its rotating shaft (300), and the negative terminal (402) is fixed on the outer frame (500); or the negative terminal (402) is fixed on the reflector (100) or its rotating shaft (300), and the positive terminal (401) is fixed on the outer frame (500).

5. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, When there are two pairs of rotating shafts, it also includes a movable frame (600), the two ends of the reflector (100) are connected to the movable frame (600) through the rotating shaft (300), and the two ends of the movable frame (600) are connected to the outer frame (500) through the second rotating shaft (310); the rotating shaft (300) and the second rotating shaft (310) are perpendicular to each other; it also includes at least two sets of capacitor groups for providing electrostatic driving force, namely the driving capacitor group (400) and the second driving capacitor group (410); The driving capacitor group (400) includes a positive electrode (401) and a negative electrode (402). The positive electrode (401) is fixed on the reflector (100) or its rotating shaft (300), and the negative electrode (402) is fixed on the movable frame (600); or the negative electrode (402) is fixed on the reflector (100) or its rotating shaft (300), and the positive electrode (401) is fixed on the movable frame (600). The second driving capacitor group (410) includes a second positive electrode (411) and a second negative electrode (412); the second positive electrode (411) is fixed on the movable frame (600) or the second rotating shaft (310) connected thereto, and the second negative electrode (412) is fixed on the outer frame (500); or the second negative electrode (412) is fixed on the movable frame (600) or the second rotating shaft (310) connected thereto, and the second positive electrode (411) is fixed on the outer frame (500); At least one adjustable capacitor (200) is provided on each of the movable frame (600) and the outer frame (500), and each group of driving capacitors (400) is connected in series with at least one adjustable capacitor (200).

6. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, When there are two pairs of rotating shafts, there are at least two waveguides (102), one of which is located at the edge of the mirror body (101); the other waveguide is also located at the edge of the mirror body (101) and is located in the area where the movable frame (600), the mirror body (101) and the first rotating shaft 300 are connected.

7. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 1, characterized in that, The driving capacitor group (400) is a parallel plate capacitor pair structure or an interleaved comb-tooth capacitor group structure. When the driving capacitor group (400) is a parallel plate capacitor pair structure, it includes at least one positive electrode (401) and at least one negative electrode (402); the positive and negative electrodes are arranged opposite each other, and their projections perpendicular to the opposite surfaces have overlapping areas, and the distance between the positive and negative electrodes is not zero; the positive electrode (401) is disposed on the lower surface of the mirror body (101), and the negative electrode (402) is disposed below the positive electrode plate (201) and connected to the outer frame (500); the positive electrode (401) is connected to the negative electrode plate (203) of the adjustable capacitor (200), the positive electrode of the external power supply is connected to the positive electrode plate (201) of the adjustable capacitor (200), and the negative electrode of the external power supply is connected to the negative electrode (402) of the driving capacitor group (400); a dielectric block (202) is disposed between the positive electrode plate (201) and the negative electrode plate (203), which together constitute the first adjustable capacitor (200); When the driving capacitor group (400) is a comb-tooth capacitor group structure, it has at least one set of positive comb teeth and at least one set of negative comb teeth, and only one pair of rotating shafts (300); specifically: the driving capacitor group (400) includes a positive electrode (401) and a negative electrode (402), and the comb teeth of the positive electrode (401) and the negative electrode (402) are arranged in a cross pattern; all the comb teeth (401) of the positive electrode are connected to the negative electrode plate (203) of the adjustable capacitor (200), all the comb teeth of the negative electrode (402) are connected to the negative electrode of the external power supply, and the positive electrode of the external power supply is connected to the positive electrode plate (201) of the adjustable capacitor (200); a dielectric block (202) is provided between the positive electrode plate (201) and the negative electrode plate (203) to jointly form the first adjustable capacitor (200).

8. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 7, characterized in that, When the driving capacitor (400) has a comb-tooth structure and includes two pairs of rotating shafts, it also includes a movable frame (600). The two outer ends of the movable frame (600) are connected to the outer frame (500) through the second rotating shaft (310). The movable frame (600) is connected to the two ends of the reflector (100) through the rotating shaft (300). The rotating shaft (300) and the second rotating shaft (310) are perpendicular to each other. A waveguide (102) is provided on the mirror body (101). A second waveguide (112) is provided on the mirror body (101), the first rotating shaft (300) and the movable frame (600). An adjustable capacitor (200) is provided on the movable frame (600), and a second adjustable capacitor (210) is provided on the outer frame (500). The light emitted from the waveguide (102) illuminates the adjustable capacitor (200). The light emitted from the second waveguide (112) illuminates the second adjustable capacitor (210).

9. The amplitude-self-stabilized electrostatically driven MEMS micromirror chip according to claim 7, characterized in that, The dielectric block (202) is a material with an adjustable relative permittivity. The dielectric block (202) is composed of two or more materials, wherein the permittivity of at least one material increases with increasing optical power and continues to increase with increasing irradiation time; the permittivity of at least one material decreases with increasing optical power and continues to decrease with increasing irradiation time.

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