MIM waveguide optical accelerometer based on cobweb-like sensitive structure

Abstract

The invention relates to the technical field of accelerometers, in particular to an MIM waveguide optical accelerometer based on a cobweb-like sensitive structure, which comprises a substrate, a metal filling layer is arranged on the upper surface of the substrate, two transversely arranged straight waveguide slots are formed in the surface of the metal filling layer in a hollowed-out manner, the head ends of the two straight waveguide slots are closed, and the head ends of the straight waveguide slots are closed. The head ends of the two straight waveguide slots are opposite to each other, the tail ends of the two straight waveguide slots penetrate through the side face of the metal filling layer, the surface of the metal filling layer is provided with a sensitive structure in a hollowed-out mode, and the sensitive structure is located between the two straight waveguide slots. And two coupling beams are respectively formed between the sensitive structure and the head ends of the two straight waveguide slots. The problems that a traditional electromechanical accelerometer is large in inter-axis crosstalk, low in sensitivity, poor in anti-interference capacity and difficult to achieve miniaturization are solved, and the accelerometer is suitable for the fields of aerospace, unmanned systems, precise navigation, structural health monitoring and the like.

Description

Technical Field

[0001] This invention relates to the field of accelerometer technology, specifically a MIM waveguide optical accelerometer based on a spider web-like sensitive structure. Background Technology

[0002] Accelerometers, as core sensors for measuring object acceleration, are widely used in aerospace, unmanned systems, precision navigation, and structural health monitoring. However, in practical applications, traditional electromechanical accelerometers (such as piezoresistive and capacitive accelerometers) generally suffer from problems such as large inter-axis crosstalk, low sensitivity, poor anti-interference ability, and difficulty in miniaturization due to their inherent structural limitations. Therefore, traditional electromechanical accelerometers exhibit significant limitations when facing application requirements for low crosstalk, high sensitivity, high anti-interference, and compact integration. Based on this, it is necessary to invent a MIM waveguide optical accelerometer based on a spiderweb-like sensing structure to solve the problems of large inter-axis crosstalk, low sensitivity, poor anti-interference ability, and difficulty in miniaturization of traditional electromechanical accelerometers. Summary of the Invention

[0003] To address the problems of large inter-axis crosstalk, low sensitivity, poor anti-interference ability, and difficulty in miniaturization of traditional electromechanical accelerometers, this invention provides a MIM waveguide optical accelerometer based on a spider web-like sensitive structure.

[0004] This invention is achieved using the following technical solution: A MIM waveguide optical accelerometer based on a spider web-like sensing structure includes a substrate; a metal filling layer is disposed on the upper surface of the substrate; The surface of the metal filler layer has two horizontally arranged straight waveguide slots. The beginning ends of the two straight waveguide slots are closed and face each other. The end ends of the two straight waveguide slots penetrate the side of the metal filler layer. The surface of the metal filling layer is also perforated with a sensitive structure; the sensitive structure is located between two straight waveguide slots, and two coupling beams are formed between the sensitive structure and the beginning of the two straight waveguide slots respectively.

[0005] Furthermore, the sensitive structure includes an annular waveguide slot, four waveguide cavities, and four bent waveguide slots, all hollowed out on the surface of the metal filling layer. Two coupling beams are formed between the beginning ends of the annular waveguide slot and the two straight waveguide slots, respectively. The four waveguide cavities are distributed circumferentially on the inner side of the annular waveguide slot, and all four waveguide cavities are connected to the annular waveguide slot. The four bent waveguide slots and the four waveguide cavities are staggered circumferentially, and each bent waveguide slot is connected to two adjacent waveguide cavities. The four bent waveguide slots and the four waveguide cavities together enclose a central mass block and four sensitive beams extending to the side of the central mass block. Two of the sensitive beams are arranged laterally, and the other two are arranged longitudinally. A distance is left between the lower surface of each sensitive beam and the upper surface of the substrate. The four bent waveguide slots, the four waveguide cavities, and the annular waveguide slots together enclose four peripheral mass blocks.

[0006] Furthermore, the substrate is a silicon substrate; the metal filling layer is a silver filling layer.

[0007] Furthermore, the annular waveguide slot is a regular hexagonal annular waveguide slot; the central mass block is a square central mass block.

[0008] Compared with traditional electromechanical accelerometers, the MIM waveguide optical accelerometer based on a spiderweb-like sensing structure described in this invention achieves the measurement of x-axis and y-axis acceleration through a novel structure, thus possessing the following advantages: First, by incorporating a spiderweb-like design (imitating a spiderweb in the sensing structure), this invention ensures anisotropic strain distribution caused by acceleration in different directions within the sensing structure, significantly reducing inter-axis crosstalk and thus effectively meeting the application requirements for low crosstalk. Second, by utilizing the unique subwavelength confinement, localized field enhancement characteristics, and compact size advantages of the MIM (Metal-Insulator-Metal) waveguide structure, this invention offers advantages such as high sensitivity, strong anti-interference capability, and ease of miniaturization, thus effectively meeting the application requirements for high sensitivity, high anti-interference, and compact integration.

[0009] This invention effectively solves the problems of large inter-axis crosstalk, low sensitivity, poor anti-interference ability, and difficulty in miniaturization of traditional electromechanical accelerometers, and is applicable to aerospace, unmanned systems, precision navigation, structural health monitoring and other fields. Attached Figure Description

[0010] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0011] Figure 2 This is a three-dimensional structural diagram of the metal filling layer in this invention.

[0012] Figure 3 This is a schematic diagram of the planar structure of the metal filling layer in this invention.

[0013] Figure 4 This is a schematic diagram showing the formation of at least two Fano resonance peaks in the transmission spectrum.

[0014] In the figure: 1-substrate, 201-straight waveguide slot, 202-ring waveguide slot, 203-waveguide cavity, 204-bent waveguide slot, 205-coupled beam, 206-central mass block, 207-sensitive beam, 208-peripheral mass block. Detailed Implementation

[0015] A MIM waveguide optical accelerometer based on a spider web-like sensing structure includes a substrate 1; a metal filling layer is disposed on the upper surface of the substrate 1. The surface of the metal filler layer has two horizontally arranged straight waveguide slots 201. The beginning ends of the two straight waveguide slots 201 are closed and the beginning ends of the two straight waveguide slots 201 are directly opposite each other. The end ends of the two straight waveguide slots 201 penetrate the side of the metal filler layer. The surface of the metal filling layer is also perforated with a sensitive structure; the sensitive structure is located between two straight waveguide slots 201, and two coupling beams 202 are formed between the sensitive structure and the beginning of the two straight waveguide slots 201 respectively.

[0016] During operation, a light source is connected to the tail end of the first straight waveguide slot 201, and a photodetector and a host computer are connected to the tail end of the second straight waveguide slot 201.

[0017] The specific working process is as follows: The light source outputs light waves, which excite SPPs (Surface Plasmon Polaritons) on the side of the first straight waveguide slot 201. The SPPs propagate along the side of the first straight waveguide slot 201 and are coupled into the sensitive structure through the first coupling beam 202. Then, SPR (Surface Plasmon Resonance) occurs in the sensitive structure. The resonance energy generated by the SPR is coupled into the second straight waveguide slot 201 through the second coupling beam 202 and propagates along the side of the second straight waveguide slot 201 to the photodetector. The photodetector then converts the signal into an electrical signal, which is transmitted to the host computer and converted into a transmission spectrum. A Fano resonance peak is formed in the transmission spectrum.

[0018] When there is no acceleration input, the sensitive structure does not deform, and the Fano resonance peak does not shift. In this case, the output of the invention is zero. When there is acceleration input, the sensitive structure deforms under the action of acceleration, causing the Fano resonance peak to shift, and the amount of shift is related to the input acceleration. At this time, the host computer calculates the input acceleration in real time based on the Fano resonance peak shift.

[0019] The sensitive structure includes an annular waveguide slot 203, four waveguide cavities 204, and four bent waveguide slots 205, all perforated on the surface of the metal filling layer. Two coupling beams 202 are formed between the annular waveguide slot 203 and the two straight waveguide slots 201, respectively. The four waveguide cavities 204 are distributed circumferentially on the inner side of the annular waveguide slot 203, and all four waveguide cavities 204 are connected to the annular waveguide slot 203. The four bent waveguide slots 205 and the four waveguide cavities 204 are staggered circumferentially, and each bent waveguide slot 205... Each of the four waveguide slots 205 and the four waveguide cavities 204 are connected to the two adjacent waveguide cavities 204. The four bent waveguide slots 205 and the four waveguide cavities 204 together enclose the central mass block 206 and the four sensitive beams 207 extending on the side of the central mass block 206. Two of the sensitive beams 207 are arranged laterally and the other two are arranged longitudinally. There is a distance between the lower surface of each sensitive beam 207 and the upper surface of the substrate 1. The four bent waveguide slots 205, the four waveguide cavities 204 and the annular waveguide slot 203 together enclose the four peripheral mass blocks 208.

[0020] During operation, at least two Fano resonance peaks are formed in the transmission spectrum, one corresponding to the x-axis and the other to the y-axis, such as... Figure 4 As shown.

[0021] When there is no acceleration input in the x-axis direction, the two longitudinally arranged sensitive beams 207 do not deform, and the corresponding Fano resonance peak does not shift. At this time, the output of this invention in the x-axis direction is zero. When there is acceleration input in the x-axis direction, the two longitudinally arranged sensitive beams 207 bend and deform under the action of acceleration, causing the corresponding Fano resonance peak to shift, and the amount of shift is related to the acceleration input in the x-axis direction. At this time, the host computer calculates the acceleration input in the x-axis direction in real time based on the Fano resonance peak shift.

[0022] When there is no acceleration input in the y-axis direction, the two laterally positioned sensitive beams 207 do not deform, and the corresponding Fano resonance peak does not shift. At this time, the output of this invention in the y-axis direction is zero. When there is acceleration input in the y-axis direction, the two laterally positioned sensitive beams 207 bend and deform under the action of acceleration, causing the corresponding Fano resonance peak to shift, and the amount of shift is related to the acceleration input in the y-axis direction. At this time, the host computer calculates the acceleration input in the y-axis direction in real time based on the Fano resonance peak shift.

[0023] The substrate 1 is a silicon substrate; the metal filling layer is a silver filling layer.

[0024] The annular waveguide slot 203 is a regular hexagonal annular waveguide slot; the central mass block 206 is a square central mass block.

[0025] In specific implementation, the thickness of the metal filling layer is 50nm; the width of the straight waveguide slot 201 is 50nm; the width of the narrowest part of the coupling beam 202 is 10nm; the side length of the regular hexagonal annular waveguide slot is 400nm; the side length of the square central mass block is 200nm; and the length of the sensitive beam 207 is 180nm and the width is 30nm.

[0026] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A MIM waveguide optical accelerometer based on a spider web-like sensing structure, characterized in that: Includes a substrate (1); the upper surface of the substrate (1) is provided with a metal filler layer; The surface of the metal filler layer has two horizontally arranged straight waveguide slots (201) cut out; the beginning ends of the two straight waveguide slots (201) are closed and the beginning ends of the two straight waveguide slots (201) face each other; the end ends of the two straight waveguide slots (201) penetrate the side of the metal filler layer. The surface of the metal filling layer is also perforated with a sensitive structure; the sensitive structure is located between two straight waveguide slots (201), and two coupling beams (202) are formed between the sensitive structure and the beginning of the two straight waveguide slots (201).

2. The MIM waveguide optical accelerometer based on a spiderweb-like sensing structure according to claim 1, characterized in that: The sensitive structure includes an annular waveguide slot (203) hollowed out on the surface of the metal filling layer, four waveguide cavities (204), and four bent waveguide slots (205); two coupling beams (202) are respectively formed between the beginning ends of the annular waveguide slot (203) and the two straight waveguide slots (201); the four waveguide cavities (204) are distributed circumferentially on the inner side of the annular waveguide slot (203), and all four waveguide cavities (204) are connected to the annular waveguide slot (203); the four bent waveguide slots (205) and the four waveguide cavities (204) are staggered circumferentially, and each bent waveguide slot (205) All are connected to the two adjacent waveguide cavities (204); the four bent waveguide slots (205) and the four waveguide cavities (204) together enclose to form a central mass block (206) and four sensitive beams (207) extending on the side of the central mass block (206); two of the sensitive beams (207) are arranged laterally, and the other two are arranged longitudinally; there is a distance between the lower surface of each sensitive beam (207) and the upper surface of the substrate (1); the four bent waveguide slots (205), the four waveguide cavities (204), and the annular waveguide slots (203) together enclose to form four peripheral mass blocks (208).

3. The MIM waveguide optical accelerometer based on a spiderweb-like sensing structure according to claim 1, characterized in that: The substrate (1) is a silicon substrate; the metal filling layer is a silver filling layer.

4. The MIM waveguide optical accelerometer based on a spiderweb-like sensing structure according to claim 2, characterized in that: The annular waveguide slot (203) is a regular hexagonal annular waveguide slot; the central mass block (206) is a square central mass block.

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