An air pressure sensor based on an optical fiber ring resonator

Abstract

The present invention is a barometric pressure sensor based on an optical fiber ring resonator. The present invention relates to the technical field of optical sensing, and includes a voltage source, a light source, an optical fiber coupler, an optical fiber ring, a first gas chamber, a second gas chamber, an outer casing, a photodetector, and a processing system. The present invention includes an optical fiber ring resonator, which comprises an optical fiber ring, a sealed gas chamber, and an open gas chamber. When the barometric pressure of the measured environment changes, it will cause a change in the cavity length of the optical fiber ring resonator, thereby changing the free spectral range of the optical fiber ring resonator. Therefore, the present invention has the advantages of simple structure, anti-electromagnetic interference, good anti-corrosion performance, fast response speed, and high degree of intelligence and integration.

Description

Technical Field

[0001] The present invention relates to the technical field of optical sensing, and is a barometric pressure sensor based on an optical fiber ring resonator. Background Art

[0002] The barometric pressure sensor on the regenerated organic resin composite profile device can transmit the internal pressure change in real time, accurately grasp the pressure change of the internal waste gas, thereby reflecting the melting state of the material, so as to adjust the data parameters in time when an abnormality occurs and avoid unqualified profiles during extrusion molding. However, the barometric pressure sensor currently used on the regenerated organic resin composite profile device has low sensitivity, is easily corroded and damaged, and needs to be frequently replaced, which not only wastes manpower and material resources, but also delays the production progress of the profiles. Therefore, the pressure value change is currently judged by experience. A barometric pressure sensor with high sensitivity and corrosion resistance can effectively solve the above problems, can not only accurately and effectively feedback the pressure change, but also is beneficial to the later automation and intelligent transformation of the regenerated organic resin composite profile device.

[0003] At present, the physical and chemical properties of waste photoresist waste are tested and analyzed to study the structural characteristics and particle specific surface area of waste photoresist; automated equipment such as waste photoresist, automatic waste gas treatment equipment, resin surface activation equipment, and harmless treatment of waste resin are designed and developed during the WEEE plastic recycling process, and corresponding production lines are built; the production wastewater and waste gas generated during the composite material preparation process are treated. For VOCs in waste gas, based on the traditional photocatalytic oxidation technology, a low-temperature plasma device is developed, and the effects of parameters such as electron energy, electron density, gas temperature, and pollutant gas components on the reaction efficiency are studied to improve the catalytic activity; the photochemical coupling low-temperature plasma device is designed and manufactured to realize the integrated equipment and technology for waste gas treatment, and the harmless goal of secondary pollution generated during the whole process is achieved. A barometric pressure sensor is an instrument for measuring barometric pressure. The essence of barometric pressure is the collision of gas atoms or gas molecules against the container wall, reflecting the rarefaction degree of the gas, which is of great significance to people's life and production. Relative barometric pressure is calculated based on the local atmospheric pressure at that time and place, also known as gauge pressure. The most widely used at present is the mechanical barometric pressure sensor, which has the advantages of high mechanical strength, convenient production, and low cost, but the disadvantages are also very obvious. For example, it has low sensitivity, low degree of intelligence and integration. Especially in the biological and chemical fields, it can only be used to measure barometric pressure in a dry and non-corrosive environment, and it is difficult to meet the needs of modern industrial development.

[0004] A barometric pressure sensor is an instrument used to measure barometric pressure. The essence of barometric pressure is the collision of gas atoms or gas molecules against the container wall, which reflects the rarefaction degree of the gas and is of great significance to people's life and production. Currently, a widely used barometric pressure sensor is the mercury barometer, which measures by balancing the gravity of mercury and gas pressure. However, the accuracy of manual reading is very limited and it is easily affected by other factors in the environment. Another widely used barometric pressure sensor is the electronic barometer. Compared with the mercury barometer, it has higher sensitivity and better stability, but its disadvantages are also very obvious. For example, it is easily affected by electromagnetic interference, has complex preparation processes, high costs, poor adaptability, etc. Especially in the fields of biology and chemistry, its corrosion resistance is poor and it can only be used to measure the gas pressure in dry and non-corrosive environments, making it difficult to meet the needs of modern industrial development.

[0005] Optical fiber devices have the advantages of simple structure, small size, light weight, low loss, good spectral characteristics, high reliability, etc. Currently, optical fibers are increasingly widely used in the field of sensing, and the great advantages of optical fiber sensors are gradually emerging. For example, they have high sensitivity, anti-electromagnetic interference, little impact on the measured environment, fast response speed, high degree of intelligence and integration, etc. Especially, optical fiber sensors are suitable for working in harsh environments and can be used to measure environments with strong electromagnetic radiation, strong nuclear radiation, and strong corrosion in the fields of physics, biology, chemistry, etc. Summary of the Invention

[0006] In view of the above defects or improvement requirements of the prior art, a barometric pressure sensor based on an optical fiber ring resonator overcomes the problems of complex structure, susceptibility to electromagnetic interference, poor corrosion resistance, slow response speed, and low degree of intelligence and integration of current barometric pressure sensors.

[0007] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0008] The present invention provides a barometric pressure sensor based on an optical fiber ring resonator, and the present invention provides the following technical solutions:

[0009] A barometric pressure sensor based on an optical fiber ring resonator, the sensor includes: a voltage source, a light source, an optical fiber coupler, an optical fiber ring, a first gas chamber, a second gas chamber, an outer sleeve, a photodetector, and a processing system;

[0010] The optical output end of the light source is connected to the first optical input end of the fiber optic coupler. The fiber optic loop is connected to the second optical output end and the second optical input end of the fiber optic coupler. There are two unclosed parts in the fiber optic loop. An outer sleeve is outside the fiber optic loop and wraps the two unclosed parts of the fiber optic loop, so that a first gas chamber and a second gas chamber are formed at the two unclosed parts of the fiber optic loop. A small hole on the side of the outer sleeve communicates with the first gas chamber. The first optical output end of the fiber optic coupler is connected to the optical input end of the photodetector. The first electrical output end of the voltage source is connected to the voltage modulation input end of the light source. The second electrical output end of the voltage source is connected to the first electrical input end of the processing system. The electrical output end of the photodetector is connected to the second electrical input end of the processing system. The electrical output end of the processing system outputs a sensor output signal.

[0011] The fiber optic coupler 3, the fiber optic loop 4, the first gas chamber 5, and the second gas chamber 6 form a fiber optic ring resonator.

[0012] Preferably, the first gas chamber is open. The first gas chamber communicates with the external environment through the small hole on the side of the outer sleeve, and the gas flows freely between the first gas chamber and the external environment.

[0013] The second gas chamber is sealed. The second gas chamber is sealed inside the outer sleeve and is filled with gas. When the outer sleeve has no deformation, the air pressure in the second gas chamber is a known air pressure P.

[0014] Preferably, the voltage source outputs a periodic triangular wave voltage. The triangular wave voltage is applied to the voltage modulation input end of the light source to tune the frequency of the output light of the light source, and the tuning range of the output light frequency of the light source is greater than twice the free spectral range of the fiber optic ring resonator.

[0015] Preferably, the fiber optic loop is a fiber optic loop with two unclosed parts composed of three sections of optical fiber. The optical fiber of the fiber optic loop wrapped by the outer sleeve is fixed inside the outer sleeve.

[0016] Preferably, the fiber optic coupler, the fiber optic loop, the first gas chamber, and the second gas chamber form a fiber optic ring resonator.

[0017] Preferably, the processing system includes an acquisition circuit, a comparison and analysis circuit, and an output circuit.

[0018] The first electrical input terminal of the acquisition circuit is the first electrical input terminal of the processing system, the second electrical input terminal of the acquisition circuit is the second electrical input terminal of the processing system, and the electrical output terminal of the output circuit is the electrical output terminal of the processing system; the second electrical output terminal of the voltage source is connected to the first electrical input terminal of the acquisition circuit, the electrical output terminal of the photodetector is connected to the second electrical input terminal of the acquisition circuit, the first electrical output terminal of the acquisition circuit is connected to the first electrical input terminal of the comparison and analysis circuit, the second electrical output terminal of the acquisition circuit is connected to the second electrical input terminal of the comparison and analysis circuit, the electrical output terminal of the comparison and analysis circuit is connected to the electrical input terminal of the output circuit, and the electrical output terminal of the output circuit outputs the sensor output signal.

[0019] A pressure detection device, and the detection device is a pressure sensor based on an optical fiber ring resonator.

[0020] A measurement method for a pressure sensor based on an optical fiber ring resonator, and the method includes the following steps:

[0021] When the outer casing is not deformed, record the transmission spectrum of the optical fiber ring resonator and denote this transmission spectrum as "transmission spectrum Λ", obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "first free spectral range";

[0022] Place the first gas chamber in the measured environment so that the air pressure in the first gas chamber is equal to the air pressure in the measured environment. At this time, record the transmission spectrum of the optical fiber ring resonator and denote this transmission spectrum as "transmission spectrum Λ", then obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "second free spectral range", and classify it into the following three cases according to the magnitudes of the first free spectral range and the second free spectral range:

[0023] When the first free spectral range is equal to the second free spectral range, it is determined that the air pressure in the measured environment is equal to the known air pressure P;

[0024] When the first free spectral range is less than the second free spectral range, it is determined that the air pressure in the measured environment is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the second free spectral range and the first free spectral range;

[0025] When the first free spectral range is greater than the second free spectral range, it is determined that the air pressure in the measured environment is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the first free spectral range and the second free spectral range.

[0026] A computer-readable storage medium, on which a computer program is stored, and the program is executed by a processor to be used to implement a measurement method for a pressure sensor based on an optical fiber ring resonator.

[0027] A computer device includes a memory and a processor. A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a measurement method of a barometric pressure sensor based on an optical fiber ring resonator.

[0028] The present invention has the following beneficial effects:

[0029] The present invention includes an optical fiber ring resonator, which includes an optical fiber ring, a sealed gas chamber, and an open gas chamber. When the barometric pressure of the measured environment changes, it will cause a change in the cavity length of the optical fiber ring resonator, thereby changing the free spectral range of the optical fiber ring resonator. Therefore, the present invention has the advantages of simple structure, anti-electromagnetic interference, good anti-corrosion performance, fast response speed, high degree of intelligence and integration. Description of the Drawings

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 It is a waveform diagram of the triangular wave voltage output by the voltage source;

[0033] Figure 3 It is a schematic diagram of the circuit structure of the processing system. Specific Embodiments

[0034] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The present invention is described in detail below in conjunction with specific embodiments. Specific Embodiment 1:

[0040] According to Figures 1 to 3 As shown, the specific optimized technical solution adopted by the present invention to solve the above technical problems is: The present invention relates to a barometric pressure sensor based on an optical fiber ring resonator.

[0041] The object of the present invention is achieved as follows: A barometric pressure sensor based on an optical fiber ring resonator, comprising: a voltage source 1, a light source 2, an optical fiber coupler 3, an optical fiber ring 4, a first gas chamber 5, a second gas chamber 6, an outer sleeve 7, a photodetector 8, and a processing system 9.

[0042] The optical output end of the light source 2 is connected to the first optical input end of the fiber optic coupler 3. The fiber optic loop 4 is connected to the second optical output end and the second optical input end of the fiber optic coupler 3. The fiber optic loop 4 is a fiber optic loop with two unclosed parts. The outer sleeve 7 is outside the fiber optic loop 4 and wraps the two unclosed parts of the fiber optic loop 4, so that a first gas chamber 5 and a second gas chamber 6 are formed at the two unclosed parts of the fiber optic loop 4. The small hole on the side of the outer sleeve 7 communicates with the first gas chamber 5. The first optical output end of the fiber optic coupler 3 is connected to the optical input end of the photodetector 8. The first electrical output end of the voltage source 1 is connected to the voltage modulation input end of the light source 2. The second electrical output end of the voltage source 1 is connected to the first electrical input end of the processing system 9. The electrical output end of the photodetector 8 is connected to the second electrical input end of the processing system 9. The electrical output end of the processing system 9 outputs a sensor output signal;

[0043] The fiber optic coupler 3, the fiber optic loop 4, the first gas chamber 5, and the second gas chamber 6 constitute a fiber optic ring resonator;

[0044] The outer sleeve 7 is elastic, and the elastic coefficient of the outer sleeve 7 is known;

[0045] The first gas chamber 5 is open. The first gas chamber 5 communicates with the external environment through the small hole on the side of the outer sleeve 7, and gas can flow freely between the first gas chamber 5 and the external environment;

[0046] The second gas chamber 6 is sealed. The second gas chamber 6 is sealed inside the outer sleeve 7. The second gas chamber 6 is filled with gas. When the outer sleeve 7 has no deformation, the air pressure in the second gas chamber 6 is a known air pressure P;

[0047] The fiber optic loop 4 is a fiber optic loop with two unclosed parts composed of three sections of optical fiber. The optical fiber of the fiber optic loop 4 wrapped by the outer sleeve 7 is fixed inside the outer sleeve 7;

[0048] The reflectivity of the inner surface of the outer sleeve 7 to the output light of the light source 2 is relatively large, so that the power of the output light at the first optical output end of the fiber optic coupler 3 meets the detection requirements of the photodetector 8;

[0049] The voltage source 1 outputs a periodic triangular wave voltage. The waveform of the triangular wave voltage is as shown in the appendix Figure 2 shown. The triangular wave voltage is applied to the voltage modulation input end of the light source 2 to tune the frequency of the output light of the light source 2, and the tuning range of the frequency of the output light of the light source 2 is greater than twice the free spectral range of the fiber optic ring resonator;

[0050] The output light of the light source 2 is continuous in time. The line width of the light is less than the line width of the transmission valley of the fiber optic ring resonator. The frequency of the light is determined by the voltage at the voltage modulation input end of the light source 2, and the relationship between the frequency of the light and the voltage at the voltage modulation input end of the light source 2 is a linear relationship;

[0051] The described processing system 9 consists of a collection circuit 9-1, a comparison and analysis circuit 9-2, and an output circuit 9-3;

[0052] The first electrical input terminal of the collection circuit 9-1 is the first electrical input terminal of the processing system 9, the second electrical input terminal of the collection circuit 9-1 is the second electrical input terminal of the processing system 9, and the electrical output terminal of the output circuit 9-3 is the electrical output terminal of the processing system 9; the second electrical output terminal of the voltage source 1 is connected to the first electrical input terminal of the collection circuit 9-1, the electrical output terminal of the photodetector 8 is connected to the second electrical input terminal of the collection circuit 9-1, the first electrical output terminal of the collection circuit 9-1 is connected to the first electrical input terminal of the comparison and analysis circuit 9-2, the second electrical output terminal of the collection circuit 9-1 is connected to the second electrical input terminal of the comparison and analysis circuit 9-2, the electrical output terminal of the comparison and analysis circuit 9-2 is connected to the electrical input terminal of the output circuit 9-3, and the electrical output terminal of the output circuit 9-3 outputs the sensor output signal.

[0053] When measuring the air pressure of the measured environment in the present invention, the first gas chamber 5 should be placed in the measured environment so that the air pressure in the first gas chamber 5 is equal to the air pressure of the measured environment;

[0054] (2) When the air pressure of the measured environment is equal to the known air pressure P, the air pressure in the first gas chamber 5 is equal to the air pressure in the second gas chamber 6. Compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, the length of the second gas chamber 6 remains unchanged, the cavity length of the fiber optic ring resonator remains unchanged, and at this time, the free spectral range of the fiber optic ring resonator remains unchanged;

[0055] (3) When the air pressure of the measured environment is greater than the known air pressure P, the air pressure in the first gas chamber 5 is greater than the air pressure in the second gas chamber 6. Compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, the length of the second gas chamber 6 decreases, the cavity length of the fiber optic ring resonator decreases, and at this time, the free spectral range of the fiber optic ring resonator increases;

[0056] (4) When the air pressure of the measured environment is less than the known air pressure P, the air pressure in the first gas chamber 5 is less than the air pressure in the second gas chamber 6. Compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, the length of the second gas chamber 6 increases, the cavity length of the fiber optic ring resonator increases, and at this time, the free spectral range of the fiber optic ring resonator decreases. Specific Embodiment 2:

[0058] Combined with Figure 1 、 Figure 2 、 Figure 3 To illustrate this embodiment, this embodiment consists of a voltage source 1, a light source 2, a fiber optic coupler 3, a fiber optic ring 4, a first gas chamber 5, a second gas chamber 6, an outer sleeve 7, a photodetector 8, and a processing system 9;

[0059] The optical output end of the light source 2 is connected to the first optical input end of the fiber optic coupler 3. The fiber optic loop 4 is connected to the second optical output end and the second optical input end of the fiber optic coupler 3. The fiber optic loop 4 is a fiber optic loop with two unclosed parts. The outer sleeve 7 is outside the fiber optic loop 4 and wraps the two unclosed parts of the fiber optic loop 4, so that a first gas chamber 5 and a second gas chamber 6 are formed at the two unclosed parts of the fiber optic loop 4. The small hole on the side of the outer sleeve 7 communicates with the first gas chamber 5. The first optical output end of the fiber optic coupler 3 is connected to the optical input end of the photodetector 8. The first electrical output end of the voltage source 1 is connected to the voltage modulation input end of the light source 2. The second electrical output end of the voltage source 1 is connected to the first electrical input end of the processing system 9. The electrical output end of the photodetector 8 is connected to the second electrical input end of the processing system 9. The electrical output end of the processing system 9 outputs a sensor output signal.

[0060] The fiber optic coupler 3, the fiber optic loop 4, the first gas chamber 5, and the second gas chamber 6 constitute a fiber optic ring resonator.

[0061] The outer sleeve 7 is elastic, and the elastic coefficient of the outer sleeve 7 is known.

[0062] The first gas chamber 5 is open. The first gas chamber 5 communicates with the external environment through the small hole on the side of the outer sleeve 7, and gas can flow freely between the first gas chamber 5 and the external environment.

[0063] The second gas chamber 6 is sealed. The second gas chamber 6 is sealed inside the outer sleeve 7. The second gas chamber 6 is filled with gas. When the outer sleeve 7 has no deformation, the air pressure in the second gas chamber 6 is a known air pressure P.

[0064] The fiber optic loop 4 is a fiber optic loop with two unclosed parts composed of three sections of optical fiber. The optical fiber of the fiber optic loop 4 wrapped by the outer sleeve 7 is fixed inside the outer sleeve 7.

[0065] The reflectivity of the inner surface of the outer sleeve 7 to the output light of the light source 2 is relatively large, so that the power of the output light at the first optical output end of the fiber optic coupler 3 meets the detection requirements of the photodetector 8.

[0066] The voltage source 1 outputs a periodic triangular wave voltage. The waveform of the triangular wave voltage is as shown in the appendix Figure 2 shown. The triangular wave voltage is applied to the voltage modulation input end of the light source 2 to tune the frequency of the output light of the light source 2, and the tuning range of the frequency of the output light of the light source 2 is greater than twice the free spectral range of the fiber optic ring resonator.

[0067] The output light of the light source 2 is continuous in time. The line width of the light is less than the line width of the transmission valley of the fiber optic ring resonator. The frequency of the light is determined by the voltage at the voltage modulation input end of the light source 2, and the relationship between the frequency of the light and the voltage at the voltage modulation input end of the light source 2 is a linear relationship.

[0068] The described processing system 9 consists of a collection circuit 9-1, a comparison and analysis circuit 9-2, and an output circuit 9-3;

[0069] The first electrical input terminal of the collection circuit 9-1 is the first electrical input terminal of the processing system 9, the second electrical input terminal of the collection circuit 9-1 is the second electrical input terminal of the processing system 9, and the electrical output terminal of the output circuit 9-3 is the electrical output terminal of the processing system 9; The second electrical output terminal of the voltage source 1 is connected to the first electrical input terminal of the collection circuit 9-1, the electrical output terminal of the photodetector 8 is connected to the second electrical input terminal of the collection circuit 9-1, the first electrical output terminal of the collection circuit 9-1 is connected to the first electrical input terminal of the comparison and analysis circuit 9-2, the second electrical output terminal of the collection circuit 9-1 is connected to the second electrical input terminal of the comparison and analysis circuit 9-2, the electrical output terminal of the comparison and analysis circuit 9-2 is connected to the electrical input terminal of the output circuit 9-3, and the electrical output terminal of the output circuit 9-3 outputs a sensor output signal.

[0070] The working principle of the present invention:

[0071] The described optical fiber coupler 3, optical fiber loop 4, first gas chamber 5, and second gas chamber 6 form an optical fiber ring resonator, and the cavity length of the optical fiber ring resonator is equal to the sum of the lengths of the optical fiber loop 4, the first gas chamber 5, and the second gas chamber 6; The voltage source 1 outputs a periodic triangular wave voltage, and the waveform of the triangular wave voltage is as shown in the appendix Figure 2 shown. The voltage source 1 outputs this triangular wave voltage and loads it onto the voltage modulation input terminal of the light source 2 to tune the frequency of the output light of the light source 2. At the same time, the voltage source 1 also sends this triangular wave voltage into the processing system 9. The output light of the light source 2 enters the optical fiber ring resonator through the optical fiber coupler 3. Since the reflectivity of the inner surface of the outer sleeve 7 to the output light of the light source 2 is relatively large, the power of the output light at the first optical output terminal of the optical fiber coupler 3 meets the detection requirements of the photodetector 8. Therefore, light can pass through the optical fiber loop 4, the first gas chamber 5, and the second gas chamber 6. In this way, the light is transmitted through the optical fiber ring resonator and then output by the optical fiber coupler 3 and enters the photodetector 8. The photodetector 8 converts the optical signal into a voltage signal and sends it into the processing system 9. The processing system 9 performs voltage signal acquisition, data analysis, and finally outputs a sensor output signal. The sensor output signal includes the magnitude of the air pressure;

[0072] When light enters the fiber optic ring resonator, there is light of certain specific optical wavelengths that satisfy the condition that the phase when traveling around the fiber optic ring resonator for one week is an integer multiple of 2π. These optical wavelengths are called the "resonant wavelengths" of the fiber optic ring resonator. The optical frequencies corresponding to the resonant wavelengths of the fiber optic ring resonator are called the "resonant frequencies" of the fiber optic ring resonator. The frequency intervals between any two adjacent resonant frequencies of the fiber optic ring resonator are equal, and this frequency interval is called the "free spectral range" of the fiber optic ring resonator. Light with an optical frequency equal to the resonant frequency of the fiber optic ring resonator resonates in the fiber optic ring resonator, and the transmittance of the light is minimized during resonance. Therefore, the transmission spectrum of the fiber optic ring resonator is a transmission valley with equal frequency intervals, and this frequency interval is the free spectral range of the fiber optic ring resonator;

[0073] The voltage source 1 outputs a periodic triangular wave voltage and loads it onto the voltage modulation input terminal of the light source 2 to tune the frequency of the output light of the light source 2. Since the output light of the light source 2 is continuous in time, the line width of the light is less than the line width of the transmission valley of the fiber optic ring resonator, the frequency of the light is determined by the voltage at the voltage modulation input terminal of the light source 2, and the relationship between the frequency of the light and the voltage at the voltage modulation input terminal of the light source 2 is a linear relationship. Therefore, the transmission spectrum of the fiber optic ring resonator can be obtained. At the same time, since the periodic triangular wave voltage output by the voltage source 1 enables the tuning range of the frequency of the output light of the light source 2 to be greater than twice the free spectral range of the fiber optic ring resonator, the light source 2 outputs at least two lights with optical frequencies equal to the resonant frequencies of the fiber optic ring resonator. Since the transmittance of the light with an optical frequency equal to the resonant frequency of the fiber optic ring resonator is minimized, the transmission spectrum of the fiber optic ring resonator contains at least two transmission valleys. Since the relationship between the frequency of the output light of the light source 2 and the voltage at the voltage modulation input terminal of the light source 2 is a linear relationship, the frequency intervals between any two adjacent transmission valleys in the transmission spectrum of the fiber optic ring resonator are equal, and this frequency interval is the free spectral range of the fiber optic ring resonator;

[0074] When measuring the air pressure of the measured environment in the present invention, the first gas chamber 5 needs to be placed in the measured environment. Since the first gas chamber 5 is open, the first gas chamber 5 is connected to the external environment through the small holes on the side of the outer sleeve 7, and gas can flow freely between the first gas chamber 5 and the external environment. Therefore, the air pressure in the first gas chamber 5 is equal to the air pressure of the measured environment. Since the second gas chamber 6 is sealed and the second gas chamber 6 is sealed inside the outer sleeve 7 and the second gas chamber 6 is filled with gas, when the outer sleeve 7 has no deformation, the air pressure in the second gas chamber 6 is a known air pressure P. Therefore, according to the magnitudes of the air pressure of the measured environment and the known air pressure P, it is divided into the following three cases:

[0075] ①When the air pressure of the measured environment is equal to the known air pressure P, since the air pressure in the first gas chamber 5 is equal to the air pressure of the measured environment and the air pressure in the second gas chamber 6 is equal to the known air pressure P, the air pressure in the first gas chamber 5 is equal to the air pressure in the second gas chamber 6. Since the optical fiber wrapped by the outer sleeve 7 in the optical fiber loop 4 is fixed inside the outer sleeve 7, the outer sleeve 7 is elastic and the elastic coefficient of the outer sleeve 7 is known. Therefore, compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, and the length of the second gas chamber 6 remains unchanged. In this way, the cavity length of the optical fiber ring resonator remains unchanged, and at this time, the free spectral range of the optical fiber ring resonator remains unchanged;

[0076] ②When the air pressure of the measured environment is greater than the known air pressure P, since the air pressure in the first gas chamber 5 is equal to the air pressure of the measured environment and the air pressure in the second gas chamber 6 is equal to the known air pressure P, the air pressure in the first gas chamber 5 is greater than the air pressure in the second gas chamber 6. Since the optical fiber wrapped by the outer sleeve 7 in the optical fiber loop 4 is fixed inside the outer sleeve 7, the outer sleeve 7 is elastic and the elastic coefficient of the outer sleeve 7 is known. Therefore, compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, and the length of the second gas chamber 6 decreases. In this way, the cavity length of the optical fiber ring resonator decreases, and at this time, the free spectral range of the optical fiber ring resonator increases;

[0077] ③When the air pressure of the measured environment is less than the known air pressure P, since the air pressure in the first gas chamber 5 is equal to the air pressure of the measured environment and the air pressure in the second gas chamber 6 is equal to the known air pressure P, the air pressure in the first gas chamber 5 is less than the air pressure in the second gas chamber 6. Since the optical fiber wrapped by the outer sleeve 7 in the optical fiber loop 4 is fixed inside the outer sleeve 7, the outer sleeve 7 is elastic and the elastic coefficient of the outer sleeve 7 is known. Therefore, compared with when the outer sleeve 7 has no deformation, the length of the first gas chamber 5 remains unchanged, and the length of the second gas chamber 6 increases. In this way, the cavity length of the optical fiber ring resonator increases, and at this time, the free spectral range of the optical fiber ring resonator decreases;

[0078] When measuring the air pressure of the environment to be measured, the specific measurement process of the present invention is as follows: (1) When the outer casing 7 is not deformed, record the transmission spectrum of the fiber optic ring resonator, and denote this transmission spectrum as "transmission spectrum Λ". Then, obtain the frequency interval of the transmission valleys in the transmission spectrum Λ, and denote this frequency interval as "the first free spectral range"; (2) Place the first gas chamber 5 in the environment to be measured so that the air pressure in the first gas chamber 5 is equal to the air pressure of the environment to be measured. At this time, record the transmission spectrum of the fiber optic ring resonator, and denote this transmission spectrum as "transmission spectrum Λ". Then, obtain the frequency interval of the transmission valleys in the transmission spectrum Λ, and denote this frequency interval as "the second free spectral range". According to the magnitudes of the first free spectral range and the second free spectral range, it is divided into the following three cases: ① If the first free spectral range is equal to the second free spectral range, it is determined that the air pressure of the environment to be measured is equal to the known air pressure P; ② If the first free spectral range is less than the second free spectral range, it is determined that the air pressure of the environment to be measured is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the second free spectral range and the first free spectral range; ③ If the first free spectral range is greater than the second free spectral range, it is determined that the air pressure of the environment to be measured is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the first free spectral range and the second free spectral range;

[0079] When measuring the air pressure of the environment to be measured, the photodetector 8 converts the optical signal into a voltage signal and sends it to the processing system 9. The specific measurement process of the processing system 9 is as follows: (1) When the outer casing 7 is not deformed, the processing system 9 collects the voltage signal and records it as the transmission spectrum Λ. Then, obtain the frequency interval of the transmission valleys in the transmission spectrum Λ, and denote this frequency interval as the free spectral range 1; (2) Place the first gas chamber 5 in the environment to be measured so that the air pressure in the first gas chamber 5 is equal to the air pressure of the environment to be measured. At this time, the processing system 9 collects the voltage signal and records it as the transmission spectrum Λ. Then, obtain the frequency interval of the transmission valleys in the transmission spectrum Λ, and denote this frequency interval as the free spectral range 2. According to the magnitudes of the free spectral range 1 and the free spectral range 2, it is divided into the following three cases: ① If the free spectral range 1 is equal to the free spectral range 2, it is determined that the air pressure of the environment to be measured is equal to the known air pressure P; ② If the free spectral range 1 is less than the free spectral range 2, it is determined that the air pressure of the environment to be measured is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the free spectral range 2 and the free spectral range 1; ③ If the free spectral range 1 is greater than the free spectral range 2, it is determined that the air pressure of the environment to be measured is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the free spectral range 1 and the free spectral range 2; Finally, the processing system 9 outputs the sensor output signal, and the sensor output signal includes the magnitude of the air pressure;

[0080] The working principle of the processing system 9:

[0081] The voltage source 1 outputs a periodic triangular wave voltage, and the waveform of the triangular wave voltage is as shown in the appendix Figure 2As shown, the voltage source 1 outputs this triangular wave voltage and sends it into the acquisition circuit 9-1. At the same time, the photodetector 8 converts the optical signal into a voltage signal and sends it into the acquisition circuit 9-1. Then, the specific measurement process is as follows: (1) When there is no deformation in the outer sleeve 7, the acquisition circuit 9-1 acquires the triangular wave voltage sent by the voltage source 1. At the same time, the acquisition circuit 9-1 acquires the voltage signal sent by the photodetector 8 and records it as the transmission spectrum Λ. Then, the acquisition circuit 9-1 sends the triangular wave voltage and the transmission spectrum Λ into the comparison and analysis circuit 9-2 respectively. The comparison and analysis circuit 9-2 compares the triangular wave voltage and the transmission spectrum Λ. Within the time range of any rising edge or falling edge of the triangular wave voltage, the transmission spectrum Λ is intercepted. Then, the frequency interval of the transmission valley is obtained from the intercepted part of the transmission spectrum Λ, and this frequency interval is recorded as the free spectral range 1; (2) Place the first gas chamber 5 in the environment to be measured so that the air pressure in the first gas chamber 5 is equal to the air pressure in the environment to be measured. At this time, the acquisition circuit 9-1 acquires the triangular wave voltage sent by the voltage source 1. At the same time, the acquisition circuit 9-1 acquires the voltage signal sent by the photodetector 8 and records it as the transmission spectrum Λ. Then, the acquisition circuit 9-1 sends the triangular wave voltage and the transmission spectrum Λ into the comparison and analysis circuit 9-2 respectively. The comparison and analysis circuit 9-2 compares the triangular wave voltage and the transmission spectrum Λ. Within the time range of any rising edge or falling edge of the triangular wave voltage, the transmission spectrum Λ is intercepted. Then, the frequency interval of the transmission valley is obtained from the intercepted part of the transmission spectrum Λ, and this frequency interval is recorded as the free spectral range 2. At this time, the comparison and analysis circuit 9-2 is divided into the following three situations according to the magnitudes of the free spectral range 1 and the free spectral range 2: ① If the free spectral range 1 is equal to the free spectral range 2, it is determined that the air pressure in the environment to be measured is equal to the known air pressure P; ② If the free spectral range 1 is less than the free spectral range 2, it is determined that the air pressure in the environment to be measured is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the free spectral range 2 and the free spectral range 1; ③ If the free spectral range 1 is greater than the free spectral range 2, it is determined that the air pressure in the environment to be measured is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the free spectral range 1 and the free spectral range 2; Finally, the comparison and analysis circuit 9-2 sends the air pressure information of the environment to be measured into the output circuit 9-3, and the output circuit 9-3 outputs the sensor output signal, and the sensor output signal includes the magnitude of the air pressure. Specific Embodiment Three:

[0083] The present invention provides a barometric pressure detection device, and the detection device is a barometric pressure sensor based on an optical fiber ring resonator. Specific Embodiment Four:

[0085] The present invention provides a measurement method for a barometric pressure sensor based on an optical fiber ring resonator, and the method includes the following steps:

[0086] When the outer casing has no deformation, record the transmission spectrum of the fiber optic ring resonator and denote this transmission spectrum as "transmission spectrum Λ", obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "first free spectral range";

[0087] Place the first gas chamber in the environment to be measured so that the air pressure in the first gas chamber is equal to the air pressure in the environment to be measured. At this time, record the transmission spectrum of the fiber optic ring resonator and denote this transmission spectrum as "transmission spectrum Λ", then obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "second free spectral range". According to the magnitudes of the first free spectral range and the free spectral range 2, it is divided into the following three cases:

[0088] When the first free spectral range is equal to the second free spectral range, it is determined that the air pressure in the environment to be measured is equal to the known air pressure P;

[0089] When the first free spectral range is less than the second free spectral range, it is determined that the air pressure in the environment to be measured is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the second free spectral range and the first free spectral range;

[0090] When the first free spectral range is greater than the second free spectral range, it is determined that the air pressure in the environment to be measured is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the first free spectral range and the second free spectral range. Specific Embodiment Five:

[0092] A computer-readable storage medium, on which a computer program is stored, and the program is executed by a processor to be used for implementing a measurement method of a barometric pressure sensor based on a fiber optic ring resonator. Specific Embodiment Six:

[0094] A computer device, including a memory and a processor, a computer program is stored in the memory, and when the processor runs the computer program stored in the memory, the processor executes a measurement method of a barometric pressure sensor based on a fiber optic ring resonator.

[0095] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Furthermore, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined. Any process or method description represented in a flowchart or described in other ways herein can be understood to represent a module, segment, or part of code including one or more N executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a manner that is not in the order shown or discussed, including in a substantially simultaneous manner according to the functions involved or in the reverse order, which should be understood by those skilled in the art to which the embodiments of the present invention pertain. The logic and / or steps represented in a flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion (electronic device) having one or N wirings, a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM).In addition, a computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory. It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0096] Those of ordinary skill in the art can understand that all or part of the steps carried by the method of the above embodiments can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments. In addition, in each of the embodiments of the present invention, the functional units can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0097] The above is only a preferred embodiment of a fiber optic ring resonator-based pressure sensor. The protection scope of a fiber optic ring resonator-based pressure sensor is not limited to the above embodiments. Any technical solution within this concept belongs to the protection scope of the present invention. It should be noted that for those skilled in the art, several improvements and changes made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A barometric pressure sensor based on an optical fiber ring resonator, characterized in that: The sensor includes: a voltage source, a light source, an optical fiber coupler, an optical fiber loop, a first gas chamber, a second gas chamber, an outer jacket, a photodetector, and a processing system; The light output end of the light source is connected to the first light input end of the optical fiber coupler. The optical fiber loop is connected to the second light output end and the second light input end of the optical fiber coupler. The optical fiber loop has two unclosed portions. The outer jacket is outside the optical fiber loop and wraps the two unclosed portions of the optical fiber loop, such that a first gas chamber and a second gas chamber are formed at the two unclosed portions of the optical fiber loop. A small hole on the side of the outer jacket communicates with the first gas chamber. The first light output end of the optical fiber coupler is connected to the light input end of the photodetector. The first electrical output end of the voltage source is connected to the voltage modulation input end of the light source. The second electrical output end of the voltage source is connected to the first electrical input end of the processing system. The electrical output end of the photodetector is connected to the second electrical input end of the processing system. The electrical output end of the processing system outputs the sensor output signal; The outer jacket is elastic, and the elastic coefficient of the outer jacket is known; The reflectivity of the inner surface of the outer jacket to the output light of the light source is relatively large, such that the power of the output light at the first light output end of the optical fiber coupler meets the detection requirements of the photodetector; The output light of the light source is continuous in time. The linewidth of the light is less than the linewidth of the transmission valley of the optical fiber ring resonator. The frequency of the light is determined by the voltage at the voltage modulation input end of the light source, and the relationship between the frequency of the light and the voltage at the voltage modulation input end of the light source is a linear relationship; The first gas chamber is open. The first gas chamber communicates with the external environment through the small hole on the side of the outer jacket, and gas flows freely between the first gas chamber and the external environment; The second gas chamber is sealed. The second gas chamber is sealed inside the outer jacket. The second gas chamber is filled with gas. When the outer jacket is not deformed, the air pressure in the second gas chamber is a known air pressure P; The optical fiber loop is an optical fiber loop with two unclosed portions composed of three sections of optical fiber. The optical fiber of the optical fiber loop wrapped by the outer jacket is fixed inside the outer jacket; The optical fiber coupler, the optical fiber loop, the first gas chamber, and the second gas chamber constitute an optical fiber ring resonator.

2. The sensor according to claim 1, characterized in that: The voltage source outputs a periodic triangular wave voltage. The triangular wave voltage is applied to the voltage modulation input end of the light source to tune the frequency of the output light of the light source, and the tuning range of the output light of the light source is greater than twice the free spectral range of the optical fiber ring resonator.

3. The sensor according to claim 1, wherein: The processing system includes an acquisition circuit, a comparison and analysis circuit, and an output circuit; The first electrical input end of the acquisition circuit is the first electrical input end of the processing system. The second electrical input end of the acquisition circuit is the second electrical input end of the processing system. The electrical output end of the output circuit is the electrical output end of the processing system. The second electrical output end of the voltage source is connected to the first electrical input end of the acquisition circuit. The electrical output end of the photodetector is connected to the second electrical input end of the acquisition circuit. The first electrical output end of the acquisition circuit is connected to the first electrical input end of the comparison and analysis circuit. The second electrical output end of the acquisition circuit is connected to the second electrical input end of the comparison and analysis circuit. The electrical output end of the comparison and analysis circuit is connected to the electrical input end of the output circuit. The electrical output end of the output circuit outputs the sensor output signal.

4. A barometric pressure detection device, characterized in that: The detection device is a kind of air pressure sensor based on an optical fiber ring resonator as described in any one of claims 1-3.

5. A measurement method for a barometric pressure sensor based on an optical fiber ring resonator, the method being implemented based on the barometric pressure sensor based on an optical fiber ring resonator according to claim 1, characterized in that: The method includes the following steps: When the outer casing has no deformation, record the transmission spectrum of the optical fiber ring resonator and denote this transmission spectrum as "transmission spectrum Λ", obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "first free spectral range"; Place the first gas chamber in the environment to be measured so that the air pressure in the first gas chamber is equal to the air pressure in the environment to be measured. At this time, record the transmission spectrum of the optical fiber ring resonator and denote this transmission spectrum as "transmission spectrum Λ", then obtain the frequency interval of the transmission valleys in the transmission spectrum Λ and denote this frequency interval as "second free spectral range". According to the magnitudes of the first free spectral range and the second free spectral range, it is divided into the following three cases: When the first free spectral range is equal to the second free spectral range, it is determined that the air pressure in the environment to be measured is equal to the known air pressure P; When the first free spectral range is less than the second free spectral range, it is determined that the air pressure in the environment to be measured is greater than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the second free spectral range and the first free spectral range; When the first free spectral range is greater than the second free spectral range, it is determined that the air pressure in the environment to be measured is less than the known air pressure P, and the magnitude of the air pressure is obtained from the difference between the first free spectral range and the second free spectral range.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by a processor to implement the measurement method as described in claim 5.

7. A computer device, characterized in that, It includes a memory and a processor. A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes the measurement method as described in claim 5.

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