Tunable pressure sensor with equilateral triangle resonant cavity embedded with ellipse

Abstract

The equilateral triangle resonant cavity tunable pressure sensor with an embedded ellipse belongs to the field of micro-nano optoelectronic technology; the pressure sensor comprises a base layer (1), a rectangular metal layer (2), a straight waveguide (3), an equilateral triangle resonant cavity (4) and an elliptical metal block (5); the base layer (1) is located at the bottom, the rectangular metal layer (2) and the straight waveguide (3) are arranged closely in sequence and closely attached to the base layer (1), the equilateral triangle resonant cavity (4) is located on the rectangular metal layer (2), the elliptical metal block (5) is located on the equilateral triangle resonant cavity (4), and the center of the circle coincides with the center of gravity of the equilateral triangle resonant cavity (4); the equilateral triangle resonant cavity tunable pressure sensor with an embedded ellipse has the technical advantages of simple structure, small size, tunable sensing characteristics and high sensitivity.

Description

Technical Field

[0001] The invention discloses a tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse, and belongs to the technical field of micro-nano optoelectronics. Background Art

[0002] Surface plasmon is an electromagnetic evanescent wave that propagates along the interface between metal and dielectric and decays exponentially in the direction perpendicular to the interface. It has the properties of breaking through the traditional diffraction limit and electric field constraint.

[0003] As a typical surface plasmon-based waveguide structure, the metal-dielectric-metal structure has the characteristics of high light confinement and easy manufacturing. Therefore, the metal-dielectric-metal structure based on surface plasmon has been used in different photonic components, such as optical switches, wavelength division multiplexers, filters, etc.

[0004] At present, different sensors of metal-medium-metal structure based on surface plasmon are designed to sense the concentration of surrounding media, ambient temperature and refractive index changes, and on this basis, sensors with high sensitivity and quality factor are designed. If they are used for pressure sensing, they can break through the problems of traditional pressure sensors with complex structure, large size and non-tunable measurement range that affect their application scope. Summary of the invention

[0005] In order to achieve the above purpose, the present invention discloses a tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse. The pressure sensor has a simple structure and a small size. The transmission characteristics of the sensor can be changed by changing the deflection angle of the liquid crystal, thereby achieving tunable measurement range.

[0006] The object of the present invention is achieved in that:

[0007] The tunable pressure sensor of an equilateral triangle resonant cavity with an embedded ellipse is composed of a base layer, a rectangular metal layer, a straight waveguide, an equilateral triangle resonant cavity and an elliptical metal block; the base layer is located at the bottom, the rectangular metal layer and the straight waveguide are arranged closely in sequence and closely attached to the top of the base layer, the equilateral triangle resonant cavity is located on the rectangular metal layer, the elliptical metal block is located on the equilateral triangle resonant cavity, and the center of the circle coincides with the center of gravity of the equilateral triangle resonant cavity.

[0008] In the above-mentioned tunable pressure sensor with an equilateral triangle resonant cavity and an embedded ellipse, the base layer is made of silicon material, and the rectangular metal layer and the elliptical metal block are made of silver material.

[0009] The above equilateral triangular resonant cavity tunable pressure sensor with an embedded ellipse has a size of 1160nm×530nm×50nm, a width of the straight waveguide of w=50nm, and only TM waves propagate inside. The side length of the equilateral triangular resonant cavity is q=484nm. The short axis a=15nm and the long axis b=65nm of the elliptical metal block. The distance c=10nm from the upper edge of the rectangular metal layer to the equilateral triangular resonant cavity and the distance g=10nm from the equilateral triangular resonant cavity to the straight waveguide.

[0010] The above equilateral triangle resonant cavity with an embedded ellipse is a tunable pressure sensor, wherein the straight waveguide and the equilateral triangle resonant cavity are realized by hollowing out a rectangular metal layer; the straight waveguide is filled with air; and the equilateral triangle resonant cavity is filled with liquid crystal.

[0011] Beneficial effects:

[0012] First, the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse of the present invention only includes five components: a base layer, a rectangular metal layer, a straight waveguide, an equilateral triangle resonant cavity and an elliptical metal block. Compared with traditional pressure sensors, it has the technical advantage of a simple structure.

[0013] Second, the tunable pressure sensor of the equilateral triangle resonant cavity with an embedded ellipse of the present invention has the size of each component at the nanometer level, and has the technical advantage of being small in size compared to traditional pressure sensors.

[0014] Third, the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse of the present invention can change the transmission characteristics of the sensor by changing the deflection angle of the liquid crystal. Compared with traditional pressure sensors, it has the technical advantage of tunable sensing characteristics.

[0015] Fourthly, the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse of the present invention can achieve a sensitivity of 2.23nm / MPa, which has a technical advantage of high sensitivity compared with traditional pressure sensors.

[0016] Fifth, the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse of the present invention can be applied to the field of highly integrated photonic chips in the future due to its simple structure, small size, tunable sensing characteristics and high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the tunable pressure sensor of the equilateral triangle resonant cavity with an embedded ellipse according to the present invention.

[0018] Figure 2 This is the transmittance curve when the short axis of the elliptical metal block changes.

[0019] Figure 3 It is the transmittance curve when the pressure at the bottom of the equilateral triangle resonant cavity changes.

[0020] Figure 4 It is the transmittance curve when the deflection direction of the liquid crystal changes.

[0021] In the figure: 1 substrate layer, 2 rectangular metal layer, 3 straight waveguide, 4 equilateral triangle resonant cavity, 5 elliptical metal block. DETAILED DESCRIPTION

[0022] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings. Specific implementation method 1

[0024] The structural diagram of the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse in this specific embodiment is as follows: Figure 1 As shown, the pressure sensor consists of a base layer 1, a rectangular metal layer 2, a straight waveguide 3, an equilateral triangle resonant cavity 4 and an elliptical metal block 5; the base layer 1 is located at the bottom, the rectangular metal layer 2 and the straight waveguide 3 are arranged closely in sequence and closely attached to the base layer 1, the equilateral triangle resonant cavity 4 is located on the rectangular metal layer 2, and the elliptical metal block 5 is located on the equilateral triangle resonant cavity 4, and the center of the circle coincides with the center of gravity of the equilateral triangle resonant cavity 4. Specific implementation method 2

[0026] The tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse in this specific implementation is further defined on the basis of the first specific implementation: the base layer 1 is made of silicon material, and the rectangular metal layer 2 and the elliptical metal block 5 are made of silver material. Specific implementation method three

[0028] The tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse under this specific implementation is further defined on the basis of specific implementation method one or specific implementation method two: the size of the rectangular metal layer 2 is 1160nm×530nm×50nm, the width w of the straight waveguide 3 is 50nm, only TM waves propagate inside, the side length q of the equilateral triangle resonant cavity 4 is 484nm, the short axis a of the elliptical metal block 5 is 15nm, the long axis b is 65nm, the distance c from the upper edge of the rectangular metal layer 2 to the equilateral triangle resonant cavity 4 is 10nm, and the distance g from the equilateral triangle resonant cavity 4 to the straight waveguide 3 is 10nm. Specific implementation method four

[0030] The tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse under this specific implementation is further defined on the basis of specific implementation one, specific implementation two or specific implementation three: the straight waveguide 3 and the equilateral triangle resonant cavity 4 are realized by hollowing out the rectangular metal layer 2; the straight waveguide 3 is filled with air; and the equilateral triangle resonant cavity 4 is filled with liquid crystal. Specific implementation method five

[0032] In the tunable pressure sensor with an equilateral triangle resonant cavity embedded with an ellipse in this specific embodiment, a simulation test is performed on the short axis a of the elliptical metal block 5. When the length of the short axis changes from 15nm to 35nm, the change of the transmittance curve is as follows: Figure 2 As shown, it can be seen that in the range of 1000nm to 1700nm, as a increases, the transmittance of the resonance peak decreases to a certain extent, and a red shift occurs, while the waveform remains basically unchanged. Specific implementation method 6

[0034] The tunable pressure sensor of the equilateral triangle resonant cavity with an embedded ellipse in this specific embodiment simulates the pressure on the bottom side of the equilateral triangle resonant cavity 4. When the pressure changes from 0MPa to 20MPa, the change of the transmittance curve is as follows: Figure 3 As shown, it can be seen that in the range of 1000nm to 1700nm, with the increase of pressure, the transmittance of the resonance peak increases slightly, and a blue shift phenomenon occurs at the same time, and the waveform remains basically unchanged; based on Figure 3 , and according to the fact that sensitivity is equal to the rate of change of wavelength offset with pressure change, it can be obtained that the sensitivity of the pressure sensor is 2.23nm / MPa. Specific implementation method 6

[0036] The tunable pressure sensor of the equilateral triangle resonant cavity with an embedded ellipse in this specific implementation is used to simulate the deflection angle of the liquid crystal. When the deflection angle of the liquid crystal changes from 0° to 90°, the change of the transmittance curve is as follows: Figure 4 As shown, it can be seen that in the range of 1000nm to 1700nm, as the deflection angle of the liquid crystal increases, the transmittance of the resonance peak decreases, and an obvious red shift phenomenon occurs, while the waveform remains basically unchanged; since the deflection direction of the liquid crystal can be changed by adding alternating current to the triangular resonant cavity, the sensing characteristics of the pressure sensor can be tuned when the structural parameters are fixed.

Claims

1. An equilateral triangular resonant cavity tunable pressure sensor with an embedded ellipse, comprising a base layer (1), a rectangular metal layer (2), a straight waveguide (3), an equilateral triangular resonant cavity (4) and an elliptical metal block (5); the base layer (1) is located at the bottom, the rectangular metal layer (2) and the straight waveguide (3) are arranged closely in sequence and closely attached to the base layer (1), the equilateral triangular resonant cavity (4) is located on the rectangular metal layer (2), the elliptical metal block (5) is located on the equilateral triangular resonant cavity (4), and the center of the circle coincides with the center of gravity of the equilateral triangular resonant cavity (4); It is characterized in that The base layer (1) is made of silicon material, and the rectangular metal layer (2) and the elliptical metal block (5) are made of silver material; The size of the rectangular metal layer (2) is 1160nm×530nm×50nm, the width of the straight waveguide (3) is w=50nm, only TM waves propagate inside, the side length of the equilateral triangle resonant cavity (4) is q=484nm, the short axis a=15nm and the long axis b=65nm of the elliptical metal block (5), the distance c=10nm from the upper edge of the rectangular metal layer (2) to the equilateral triangle resonant cavity (4), and the distance g=10nm from the equilateral triangle resonant cavity (4) to the straight waveguide (3).

2. The tunable pressure sensor with an equilateral triangle resonant cavity and an embedded ellipse according to claim 1, characterized in that: The straight waveguide (3) and the equilateral triangle resonant cavity (4) are realized by performing a hollowing operation on the rectangular metal layer (2); the interior of the straight waveguide (3) is filled with air; and the interior of the equilateral triangle resonant cavity (4) is filled with liquid crystal.

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