High-Temperature Pressure Detection Method Based on Weak Measurement and Sapphire Microstructure Sensor

Abstract

This invention discloses a high-temperature pressure detection method based on weak measurement and a sapphire microstructure sensor, relating to the field of high-temperature environmental pressure detection. The method includes: S1, constructing a single-layer sapphire sensor with a microstructure unit array; S2, fixing the single-layer sapphire sensor in a high-temperature device, turning on the light source emission module, and adjusting the pre-selection module; S3, integrating the light intensity of incident light passing through the sapphire microstructure via the post-selection module, and deriving the relationship between pressure and center wavelength shift; S4, turning on the high-temperature pressure module, applying high temperature and pressure to the single-layer sapphire sensor, and recording the results; S5, changing the pressure value and performing multiple repeated measurements, calculating the average value based on the measurement results, and reversing the pressure value using the formula in S3. This invention combines a weak measurement method with sapphire material, achieving weak coupling between the probe device and sapphire through a quantum system, which can significantly improve the accuracy of pressure detection under extreme high temperatures.

Description

Technical Field

[0001] This invention relates to the field of high-temperature environmental pressure detection. More specifically, this invention relates to a high-temperature pressure detection method based on weak measurement and a sapphire microstructure sensor. Background Technology

[0002] As cutting-edge engineering exploration advances towards extreme conditions, the high-temperature and high-pressure resistance of materials provides more reliable guarantees for manufacturing development and operations in extreme environments. Meanwhile, precise measurement of physical properties under extreme conditions is crucial for optimizing structural design, enhancing reliability, improving control performance, and extending lifespan. High temperature and high pressure are among the extreme operating conditions typically encountered in aerospace, laser ignition, and semiconductor manufacturing. Taking aerospace as an example, the temperature from the intake to the exhaust of an aero-engine ranges from 300°C to 600°C, with the combustion chamber temperature reaching 1000°C; the combustion chamber temperature of hypersonic aircraft engines approaches 2000°C. Extreme high temperature and high pressure can cause mutual interference between components, resulting in combustion chamber structural vibration and fatigue, shortened service life, and even catastrophic accidents. Therefore, pressure sensing under high-temperature environments is crucial for detecting and improving system stability. However, traditional electrical high-temperature pressure sensors, such as those based on SOI (Silicon On Insulator) and silicon carbide (SiC), are limited by phenomena such as piezoresistive degradation, increased leakage current, ohmic contact failure, silicon creep, and large lattice mismatch under high-temperature environments, and their maximum operating temperature generally does not exceed 750℃. Therefore, new materials or measurement methods are urgently needed to overcome this technical bottleneck.

[0003] Sapphire, also known as Al2O3, is a high-refractive-index material with extremely high transmittance in the ultraviolet to infrared band (0.18 - 4.5 μm). It is commonly used as a key window material in defense and industrial fields. Its hardness (Mohs hardness 9) is second only to diamond, and it possesses excellent chemical stability and extremely high thermal stability (melting point 2050℃), maintaining good optical performance even at temperatures as high as 1500℃. Simultaneously, it has very high thermal conductivity; at 298 K, the thermal conductivity perpendicular to the C-axis is 30.3 W / (m·K), and the thermal conductivity parallel to the C-axis is 32.5 W / (m·K), effectively reducing heat accumulation and making it highly suitable for high-temperature environments. In addition to its superior physical properties, sapphire possesses numerous excellent mechanical characteristics: at room temperature, C-cut sapphire has a Young's modulus close to 400 GPa, a tensile strength of 275-400 MPa, a flexural strength of 450-895 MPa, a compressive strength of 2 GPa, a compressive modulus of 250 GPa, a shear modulus of 140-175 GPa, and a Poisson's coefficient of 0.27-0.30. These mechanical properties give sapphire exceptional resistance to thermal shock deformation. In summary, sapphire is an ideal material for high-temperature and high-pressure applications, making it highly suitable for fabricating the sensitive structures of high-temperature pressure sensors. High-temperature pressure sensors made of sapphire are suitable for pressure measurement in the high-temperature environments of power equipment such as aerospace engines and gas turbines.

[0004] High-temperature pressure detection also faces the problem of significant noise interference. Improving the signal-to-noise ratio and achieving high-sensitivity detection are key issues that need to be addressed. Weak measurement is a technique for amplifying minute signals. Its concept originated from the exploration of quantum measurement theory and has received widespread attention since its proposal by Aharonov, Albert, and Vaidman in 1988. Its core principle is that the measured physical quantity induces a perturbation in the system, creating a weak coupling between the system and the detection device. This weak interaction results in a slight separation of orthogonal eigenstates in momentum space or coordinate space, rather than complete separation. Thus, after measurement, the system does not collapse into one of the eigenstates as in traditional quantum measurements. Weak measurement is essentially a physical process of separating the system's eigenstates. By projecting a measurement onto a post-selected state that is nearly orthogonal to the pre-selected state of the incident light, an observation value several times larger than the eigenvalue can be obtained. This process is called weak value amplification, and the amplification factor inherent in the outgoing pointer state is called the weak value. Meanwhile, since the selected states are nearly orthogonal, similar to polarization filtering systems in traditional optical systems, the interference from background noise can be greatly reduced. This characteristic of weak measurement makes its measurement accuracy 2-3 orders of magnitude higher than that of traditional interferometry.

[0005] In summary, traditional high-temperature pressure sensors are limited by problems such as piezoresistive degradation, increased leakage current, ohmic contact failure, silicon creep, and large lattice mismatch under high-temperature environments. Therefore, combining weak measurement methods with sapphire materials to achieve accurate sensing of pressure parameters under high-temperature environments has not yet been achieved in existing technologies. Summary of the Invention

[0006] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0007] To achieve these objectives and other advantages of the present invention, a high-temperature pressure detection method based on weak measurement is provided, comprising:

[0008] S1. Construct a single-layer sapphire sensor with a microstructure unit array;

[0009] S2. Fix the single-layer sapphire sensor in the high-temperature device, turn on the light source emission module, and adjust the pre-selection module so that the incident light that has completed the pre-selection is incident on the single-layer sapphire sensor and a weak interaction occurs.

[0010] S3. After the incident light passes through the sapphire microstructure, the light intensity is integrated by the selection module, and the following relationship between pressure and center wavelength shift is derived:

[0011]

[0012] In the above formula, P represents pressure. α represents the offset of the center wavelength on the spectrometer, and α is the sensitivity coefficient of the structural mechanical properties of sapphire. f 0 represents the initial volume fraction of sapphire. n 1 represents the refractive index of sapphire itself. n 2 represents the refractive index of the sapphire after laser processing modification. e For the previous selection angle, s For spectral width, L The thickness of the sapphire microstructure, l 0 represents the initial center wavelength of the light source. c The speed of light in a vacuum.

[0013] S4. Open the high-temperature and pressure module to apply high temperature and pressure to the single-layer sapphire sensor and record the results. ;

[0014] S5. Change the pressure value and repeat the measurement multiple times. Calculate the result based on the measurement. The average value is calculated, and the magnitude of the pressure value is derived from the formula in S3.

[0015] Preferably, in S2, the wave function Ⅲ of the pre-selected incident light after passing through the microstructure unit array is... It is characterized by the following formula:

[0016]

[0017] In the above formula, This represents the wave function II of the incident light after passing through the pre-selection module. , These represent the different spin modes of the photon, up and down. U This represents the weak interactions within the detection system. e Represents the natural constant. i Represents the imaginary unit. Indicates the pre-selection angle, and These are the two mutually perpendicular components of the incident light after it has been decomposed by the forward selection module.

[0018] Preferably, in S3, the process for obtaining the relationship between pressure and center wavelength shift is as follows:

[0019] S30, Wave function IV of the selected module after incident light passes through. It is characterized by the following formula:

[0020]

[0021] In the above formula, dThis represents the full width at half maximum (FWHM) of the light source. oh Represents angular frequency. t Indicates the total time delay;

[0022] S31, based on The light intensity is expressed by the following formula. Integrate points:

[0023]

[0024] In the above formula, oh 0 indicates the initial center of the spectrum;

[0025] S32, Light intensity based on integration A new center for calculating the spectrum ;

[0026] S33, based on Calculate the shift in the spectrum and according to and The relationship was derived. With time delay t Relational expression:

[0027]

[0028] S34, because Equivalent birefringence dependent on sapphire microstructure And its physical length L, therefore when the thickness L When the pressure remains constant, the center wavelength offset is used as the basis for the calculation. With time delay t relational expressions and The expression can obtain the pressure. P and center wavelength offset The relational expression.

[0029] Preferably, in S33, The expression is as follows:

[0030]

[0031] In the above formula, n e and n o These represent the refractive indices of unusual and ordinary light, respectively.

[0032] A sapphire microstructure sensor includes: a sapphire substrate and an array of microstructure units disposed inside the sapphire substrate.

[0033] Preferably, each microstructure unit in the microstructure unit array is a subwavelength periodic grating.

[0034] Preferably, each periodic grating is configured to use nanowires with a period of 300 nm;

[0035] The length and width of a single nanowire are 50µm and 170nm, respectively, and the aspect ratio of a single nanowire is 300.

[0036] Preferably, the sapphire substrate has a thickness of 500µm and a surface roughness of less than 0.5nm;

[0037] The sapphire substrate is made of double-sided polished c-phase sapphire, and the refractive index of the sapphire substrate at a wavelength of 515 nm is 1.7682.

[0038] The present invention has at least the following beneficial effects:

[0039] Firstly, this invention addresses the problem of high-temperature pressure detection failure by innovatively achieving rapid coupling of pressure parameters through sapphire microstructures and utilizing a weak measurement method to achieve ultra-sensitive detection of high-temperature pressure, significantly improving the accuracy of pressure detection under high-temperature environments. Specifically, this invention combines a weak measurement method with sapphire material, achieving weak coupling between the probe device and sapphire through a quantum system. Leveraging the weak value amplification function unique to weak measurement technology and the extreme high-temperature and high-pressure resistance of sapphire, precise sensing of pressure parameters under high-temperature environments can be achieved, significantly improving the accuracy of pressure detection under extreme high temperatures.

[0040] Secondly, the sapphire microstructure described in this invention is simple to use, reusable, and adaptable to various high-temperature and pressure detection systems. It is easy to operate, requires only micron-level processing precision, has a mature production process, low cost, and can achieve large-scale production, thus possessing good commercial application potential.

[0041] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the sapphire microstructure sensor of the present invention;

[0043] Figure 2 This is a schematic diagram of the high-temperature pressure detection system of the present invention;

[0044] Figure 3 This is an example of the initial center wavelength distribution of a sapphire microstructure sensor after calibration, as shown in this embodiment of the invention.

[0045] Figure 4 This is a graph showing the relationship between the shift of the spectrometer's center wavelength and pressure in an embodiment of the present invention;

[0046] Among them, dielectric substrate 1-1, nanograting unit 1-2, light source emission module (SLD) 2-1, front polarizer 2-2, quarter-wave plate (QWP) 2-3, Soleil-Babinet phase compensator (SBC) 2-4, sapphire microstructure sensor 2-5, high temperature and high pressure cavity 2-6, back polarizer 2-7, spectrometer 2-8, optical window I 2-9, fixing bracket 2-10, and optical window II 2-11. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0048] like Figure 1 The diagram shows a schematic of a sapphire microstructure sensor. The sapphire microstructure sensor includes a dielectric substrate (also called a base) 1-1 and nanograting units 1-2 embedded within it. Specifically, the substrate 1-1 can be a sapphire substrate with a thickness of 500 μm.

[0049] In this embodiment, the substrate 1 is a square (equilateral rectangle) with a side length of 100 μm. Sapphire microstructure periodicity. nm. The equivalent birefringence of the microstructure can be expressed by the following formula:

[0050] (1)

[0051] (2)

[0052] in, n e and n o These represent the refractive indices of unusual and ordinary light, respectively. This indicates the change in volume fraction ratio with pressure, and P represents pressure, α represents the sensitivity coefficient of sapphire's structural mechanical properties, and , f 0 represents the initial volume fraction of sapphire, and f 0 = 0.5 n 1. n 2 represents the refractive index of sapphire before and after laser modification, and n 1 = 1.7682, n 2 = 1.7000.

[0053] like Figure 2The schematic diagram shown illustrates the high-temperature pressure testing process for sapphire based on a weak measurement method. It includes, sequentially placed along the same optical axis, a light source emission module (SLD) 2-1, a pre-selection polarizer 2-2, a quarter-wave plate (QWP) 2-3 (wherein, the pre-selection polarizer 2-2 and the quarter-wave plate (QWP) 2-3 constitute the pre-selection module), a Soleil-Babinet phase compensator (SBC) 2-4, a sapphire microstructure sensor 2-5 (including a mounting bracket 2-10), a high-temperature and high-pressure chamber 2-6 (including optical window I 2-9 and optical window II 2-11), a post-selection module 2-7, and a spectrometer 2-8. The spectral range of the light source emission module and the spectral range of the spectrometer detection module should encompass and exceed the operating frequency range of the sapphire microstructure sensor.

[0054] First, fix the sapphire microstructure sensor on the sample holder, turn on the light source emission module 2-1, and observe the spectrum of the light source. g ( oh It exhibits a Gaussian distribution. g ( oh The following is represented:

[0055] (3)

[0056] in, s Indicates spectral width, and , d This represents the full width at half maximum (FWHM) of the light source. l 0 represents the initial center wavelength of the light source. , oh Represents angular frequency. oh 0 represents the initial center of the spectrum, and , c The speed of light in a vacuum.

[0057] Before adjustment, select linear polarizer 2-2 so that the angle between its polarization direction and the horizontal direction is [value missing]. ,in, e Let be the first selected angle, and Adjust the quarter-wave plate 2-3 so that the angle between its fast axis and the horizontal direction is... The incident light is decomposed into mutually perpendicular components. and After the preselected state preparation is completed, its wavefunction I is expressed as follows:

[0058] (4)

[0059] In the above formula, i Represents the imaginary unit. t This indicates the total system time delay;

[0060] After the initial selection is completed, the wave function II of the system can be expressed as follows:

[0061] (5)

[0062] In the above formula, Represents the energy eigenstate, e For the previous selection angle,

[0063] When incident light is incident orthogonally onto the sapphire microstructure sensor 2-5, a weak interaction occurs. The process of the weak interaction U is characterized by the following equation:

[0064] (6)

[0065] In the above formula, H Let Hamiltonian represent the system (here, the system is a two-level system), and , x P Represents momentum space coordinates. A Indicates polarization observable measurement, It is the interaction time.

[0066] The wave function Ⅲ after passing through the sapphire microstructure can be expressed by the following formula:

[0067] (7)

[0068] in, and These represent the different spin modes of the photon, and , t This represents the total time delay, and , x Indicates location.

[0069] After further selection by modules 2-7, the weakly coupled information is amplified, resulting in the post-selected wavefunction IV. as follows:

[0070] (8)

[0071] Light intensity after selection (light intensity) The probability amplitude of the wave function is characterized by the following formula:

[0072] (9)

[0073] The result after integration:

[0074] (10)

[0075] As can be seen from the preceding derivation, the spectrum of the function after the last choice... for:

[0076] (11)

[0077] Then, calculate the new center of the spectrum according to the following formula. :

[0078] (12)

[0080] In the above formula, This represents the spectrum of the function after selection;

[0081] In this way, the shift in the spectrum can be obtained. :

[0082] (13)

[0083] Then based on the center wavelength offset and spectral shift Relationship:

[0084] (14)

[0085] The center wavelength offset can be obtained. The expression:

[0086] (15)

[0087] Taking a first-order approximation of formula (15) yields the center wavelength shift. With time delay t The relationship is as follows:

[0088] (16)

[0089] Next, build pressure. P offset from center wavelength Relationship:

[0090] because Equivalent birefringence dependent on sapphire microstructure And its physical length L (also known as microstructure thickness).

[0091] (17)

[0092] In the above formula, This indicates the time delay introduced by stress birefringence;

[0093] When the pressure changes, assuming the thickness LWithout changing, the following pressure can be obtained from formulas (1) and (2) and formulas (16) and (17). P and center wavelength offset Relationship:

[0094] (18)

[0095] Final center wavelength The movement was detected by spectrometer 2-8 to observe two asymmetric peaks.

[0096] Example:

[0097] 1. This embodiment uses the high-precision detection of high temperature and pressure by the detection system as an example to describe the present invention in detail. The detection system includes a superluminescent diode (SLD830S-A20, Thorlabs Inc.) with a center wavelength of 830 nm, a Gaussian filter, a linear polarizer P1 (i.e., a pre-select polarizer), a quarter-wave plate QWP, a Soleil-Babinet phase compensator, a linear polarizer P2 (i.e., a post-select module), and a spectrometer, all placed sequentially on the same optical axis. The spectral range of the superluminescent diode and the spectrometer includes and is greater than the operating frequency range of the sapphire sensor.

[0098] Figure 3 It is a symmetrical double peak after calibration with a Soleil-Babinet phase compensator, corresponding to the initial state of the device. Figure 4 This image shows the pressure detection results of a sapphire microstructure sensor under high-temperature conditions. In this embodiment, the dielectric substrate 1-1 of the terahertz chip sensor is made of c-phase sapphire with a thickness of 500 μm; it is a square with sides of 100 × 100 µm, featuring a periodic grating structure with a period of 300 nm. The length and width of a single nanowire are approximately 50 µm and 170 nm, respectively, with an aspect ratio close to 300. The nanograting structure is fabricated inside the substrate using a femtosecond laser direct-writing process. All the above parameters were designed and fabricated based on the spectral response characteristics of sapphire at 830 nm.

[0099] The light source emission module (SLD) 2-1 outputs a signal with a center wavelength of 830nm, and the spectrometer 2-8 detects wavelengths ranging from 600 to 1700nm.

[0100] The first step is to take a clean and intact sapphire microstructure sensor, such as... Figure 1 As shown, the sample was fixed on the sample holder as required, and the equipment was calibrated to its initial state using a Soleil-Babinet phase compensator. The center wavelength shift was measured using spectrometer 2-8. ,at this time The spectrometer displays symmetrical double peaks, such as Figure 3 As shown.

[0101] The second step is to open the high temperature and pressure module 2-6, apply high temperature and pressure to the sapphire microstructure sensor 2-5, record the spectral data of the spectrometer 2-8, and obtain the offset value of the center wavelength of the spectrometer.

[0102] The third step involves changing the pressure value and repeating the second step multiple times to obtain multiple spectral data points containing sample information through repeated measurements.

[0103] The fourth step is to calculate the center wavelength offset based on the measurement results from the third step. And the magnitude of the pressure value can be deduced from the formula.

[0104] The above solution is merely an illustration of a preferred example and is not limited thereto. When implementing this invention, appropriate substitutions and / or modifications can be made according to the user's needs.

[0105] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Other modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A high-temperature pressure detection method based on weak measurement, characterized in that, include: S1. Construct a single-layer sapphire sensor with a microstructure unit array; S2. Fix the single-layer sapphire sensor in the high-temperature device, turn on the light source emission module, and adjust the pre-selection module so that the incident light that has completed the pre-selection is incident on the single-layer sapphire sensor and a weak interaction occurs. S3. After the incident light passes through the sapphire microstructure, the light intensity is integrated by the selection module, and the following relationship between pressure and center wavelength shift is derived: In the above formula, P represents pressure. α represents the offset of the center wavelength on the spectrometer, and α is the sensitivity coefficient of the structural mechanical properties of sapphire. f 0 represents the initial volume fraction of sapphire. n 1 represents the refractive index of sapphire itself. n 2 represents the refractive index of the sapphire after laser processing modification. ε For the previous selection angle, σ For spectral width, L The thickness of the sapphire microstructure, λ 0 represents the initial center wavelength of the light source. c The speed of light in a vacuum; S4. Open the high-temperature and pressure module to apply high temperature and pressure to the single-layer sapphire sensor and record the results. ; S5. Change the pressure value and repeat the measurement multiple times. Calculate the result based on the measurement. The average value is calculated, and the magnitude of the pressure value is derived from the formula in S3.

2. The high-temperature pressure detection method based on weak measurement as described in claim 1, characterized in that, In S2, the wave function Ⅲ of the pre-selected incident light after passing through the microstructure unit array is completed. It is characterized by the following formula: In the above formula, This represents the wave function II of the incident light after passing through the pre-selection module. , These represent the different spin modes of the photon, up and down. U This represents the Hamiltonian of the detection system. e Represents the natural constant. i Represents the imaginary unit. Indicates the pre-selection angle, and These are the two mutually perpendicular components of the incident light after it has been decomposed by the forward selection module.

3. The high-temperature pressure detection method based on weak measurement as described in claim 2, characterized in that, In S3, the process for obtaining the relationship between pressure and center wavelength shift is as follows: S30, Wave function IV of the selected module after incident light passes through. It is characterized by the following formula: In the above formula, d This represents the full width at half maximum (FWHM) of the light source. ω Represents angular frequency. τ Indicates a time delay. g ( ω () represents the spectrum of the light source; S31, based on The light intensity is expressed by the following formula. Integrate points: In the above formula, ω 0 indicates the initial center of the spectrum; S32, Light intensity based on integration A new center for calculating the spectrum ; S33, based on Calculate the shift in the spectrum and according to and The relationship was derived. With time delay τ Relational expression: S34, because Equivalent birefringence dependent on sapphire microstructure And its physical length L, therefore when the thickness L When the pressure remains constant, the center wavelength offset is used as the basis for the calculation. With time delay τ relational expressions and The expression can obtain the pressure. P and center wavelength offset The relational expression.

4. The high-temperature pressure detection method based on weak measurement as described in claim 1, characterized in that, In S33, The expression is as follows: In the above formula, n e and n o These represent the refractive indices of unusual and ordinary light, respectively.

5. A sapphire microstructure sensor, applied in the high-temperature pressure detection method based on weak measurement as described in any one of claims 1-4, characterized in that, include: It includes a sapphire substrate and an array of microstructure units disposed inside the sapphire substrate.

6. The sapphire microstructure sensor as described in claim 5, characterized in that, Each microstructure unit in the array of microstructure units is a subwavelength periodic grating.

7. The sapphire microstructure sensor as described in claim 5, characterized in that, Each periodic grating is configured to use nanowires with a period of 300 nm; The length and width of a single nanowire are 50µm and 170nm, respectively, and the aspect ratio of a single nanowire is 300.

8. The sapphire microstructure sensor as described in claim 5, characterized in that, The sapphire substrate has a thickness of 500µm and a surface roughness of less than 0.5nm; The sapphire substrate is made of double-sided polished c-phase sapphire, and the refractive index of the sapphire substrate at a wavelength of 515 nm is 1.7682.

Images