CN116818084A - Acoustic wave sensor and system based on micro-nano optical fiber coupler - Google Patents
Acoustic wave sensor and system based on micro-nano optical fiber coupler Download PDFInfo
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- CN116818084A CN116818084A CN202310774542.3A CN202310774542A CN116818084A CN 116818084 A CN116818084 A CN 116818084A CN 202310774542 A CN202310774542 A CN 202310774542A CN 116818084 A CN116818084 A CN 116818084A
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Abstract
The invention discloses an acoustic wave sensor and a system based on a micro-nano optical fiber coupler. Comprises a substrate as a base of an acoustic wave sensor; comprises a gas cavity arranged on a substrate and provided with a relatively closed gas chamber inside; the micro-nano optical fiber coupler comprises an optical sensitive part, wherein the optical sensitive part is arranged in a gas cavity; the device comprises a vibrating membrane, a vibrating membrane and a vibrating membrane, wherein the vibrating membrane is arranged on one side surface of a gas cavity, and gas in the gas cavity is in direct contact with the vibrating membrane; the optical detection assembly comprises a laser light source, a photoelectric detector and an oscilloscope. One end of the micro-nano optical fiber coupler is connected with the laser light source, the other end of the micro-nano optical fiber coupler is connected with the photoelectric detector, and the photoelectric detector is electrically connected with the oscilloscope. The invention can realize rapid and accurate detection of sound waves, has the advantages of ultrahigh sensitivity, real-time response, compact structure, low cost and the like, and has application prospects in the fields of ultrasonic monitoring, industrial nondestructive detection, robot navigation and the like.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing, and particularly relates to an acoustic wave sensor based on a micro-nano optical fiber coupler and an acoustic wave detection system.
Background
An acoustic wave is a mechanical wave caused by the propagation of vibrations of a sounding body in a medium. The sound wave detection technology utilizes the physical characteristics of sound waves to carry out non-contact detection and measurement, thereby realizing the capture and analysis of characteristic parameters such as the shape, the distance, the speed, the quality and the like of a target object. The acoustic wave detection technology has the advantages of non-contact, abundant information, no harm to human bodies and environment and the like, so that the application scene is extremely abundant, and the acoustic wave detection technology is widely applied to the fields of material characteristic detection, medical diagnosis, industrial nondestructive detection, seismic survey, robot navigation and the like.
The electrical sensor for realizing high-sensitivity acoustic wave detection based on capacitance, resistance, piezoelectricity and the like achieves excellent performance, however, the problems of parasitic capacitance, electromagnetic interference and the like limit the application range of the electrical sensor to a certain extent. Different from the traditional electrical sensing device, the acoustic wave sensing technology based on the optical fiber, which is developed gradually in recent years, combines the unique advantages of the acoustic wave detection and analysis technology and the optical fiber sensing, takes light as an information carrier, not only can immunity electromagnetic interference, but also has the advantages of high response speed, low transmission loss, easiness in multiplexing and the like, and becomes a current research hot spot.
The micro-nano optical fiber is a novel optical fiber with the diameter being close to or smaller than the wavelength of transmitted light, and is favored in the field of optical sensing due to the characteristics of strong evanescent field, low bending loss, small size and the like. The micro-nano optical fiber coupler structure based on the optical near-field coupling effect is extremely sensitive to phase change, so that the micro-nano optical fiber coupler structure is a good choice for realizing high-sensitivity sensing.
How to realize effective conduction and efficient conversion of weak acoustic signals is a primary technical problem facing the technical field of acoustic detection. Meanwhile, in order to improve the measurement accuracy and the service life of the sensor device, the effective encapsulation of the core component of the sensor to isolate the external environment pollution is also a problem to be solved in the prior art.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide the acoustic wave sensor based on the micro-nano optical fiber coupler, which realizes the effective collection and amplification of weak acoustic wave signals by innovatively introducing a vibrating diaphragm and a gas cavity structure, and can realize the high-sensitivity and real-time detection of the weak acoustic wave signals based on the micro-nano optical fiber coupler structure with high sensitivity to optical phases, thereby solving the technical problems of low sensitivity or complex structure and weak anti-interference capability of the conventional acoustic wave sensor.
The technical scheme of the invention is as follows:
1. acoustic wave sensor based on micro-nano fiber coupler:
comprises a substrate as a base of an acoustic wave sensor;
comprises a gas cavity arranged on a substrate and provided with a relatively closed gas chamber inside;
the micro-nano optical fiber coupler comprises an optical sensitive part, wherein the optical sensitive part is arranged in a gas cavity;
comprises a vibrating membrane arranged on one side surface of a gas cavity, and gas in the gas cavity is in direct contact with the vibrating membrane.
The micro-nano optical fiber coupler is packaged in a closed gas cavity, and the vibrating membrane generates vibration after receiving an acoustic wave signal, so that gas in the closed gas cavity is correspondingly extruded or expanded, and the refractive index of the gas in the closed cavity is correspondingly changed, thereby affecting the splitting ratio of the coupler and changing the signal intensity of the output end of the coupler.
The gas chamber of the gas chamber is only provided with two openings which are respectively covered by the vibrating membrane and the substrate, so that a relatively closed space is formed in the gas chamber and filled with gas.
Specifically, the gas cavity is a solid block with a through groove in the middle, and the upper end and the lower end of the through groove are used as openings.
The gas cavity can be made of PDMS, epoxy resin and other materials.
The micro-nano optical fiber coupler is arranged through the gas cavity, and the optical sensitive part is positioned in the middle of the gas cavity air chamber.
The micro-nano optical fiber coupler is provided with a tapered area part with a middle diameter thinner than other parts, and the tapered area part is used as an optical sensitive part.
The micro-nano optical fiber coupler is formed by arranging at least two tapered optical fibers in parallel and side by side, and tapered area parts of the tapered optical fibers are tightly connected and bonded into a whole.
Specifically, the micro-nano optical fiber coupler is manufactured by fusing and stretching two identical optical fibers after the two optical fibers are close together, and the tapered area parts of the two optical fibers are in close contact with each other to form an optical near-field coupling structure which is used as an optical sensitive part.
The refractive index of the substrate is lower than that of the tapered optical fiber in the micro-nano optical fiber coupler.
The substrate is made of quartz glass material with PDMS coated on the surface.
The vibrating diaphragm can convert external sound wave signals into self vibration so as to drive gas in a gas chamber of the gas chamber to vibrate.
The vibrating diaphragm is made of PET or PMMA materials.
2. Acoustic wave detection system based on micro-nano fiber coupler:
the sound wave sensor is included;
the device comprises at least one group of optical detection assemblies, wherein each group of optical detection assemblies comprises a laser light source, a photoelectric detector and an oscilloscope, one end of a micro-nano optical fiber coupler in the acoustic wave sensor is connected with the laser light source, the other end of the micro-nano optical fiber coupler is connected with the photoelectric detector, and the photoelectric detector is electrically connected with the oscilloscope.
One embodiment is to include a set of optical detection components connected to a single fiber input end and a single fiber output end of a micro-nano fiber coupler in an acoustic wave sensor.
One embodiment is to include two sets of optical detection components, and the micro-nano fiber coupler includes two optical fibers, the two sets of optical detection components are respectively connected to two optical fiber inputs and two optical fiber outputs of one micro-nano fiber coupler in the acoustic wave sensor.
The sound wave sensor and the sound wave detection system of the invention receive sound wave signals through the vibrating membrane covered on the surface of the gas cavity, vibrate and convert the sound wave signals into gas refractive index changes in the sealed gas cavity, thereby changing the optical coupling state of the optical near-field coupling structure in the micro-nano optical fiber coupler. The high sensitivity of the optical near-field coupling structure of the micro-nano optical fiber coupler to the environment refractive index is benefited, so that the sound wave finally causes the signal intensity of the output end of the micro-nano optical fiber coupler to change. The sensor can realize high-sensitivity and real-time detection of sound waves.
The vibration film of the invention vibrates after receiving the sound wave signals, so that the refractive index of the gas in the closed gas cavity is changed, the environment refractive index of the optical near-field coupling structure in the micro-nano optical fiber coupler is changed, the splitting ratio of the output end of the coupler is changed, and the sound wave can be detected by detecting the light intensity change of the output end of the micro-nano optical fiber coupler.
Compared with the prior art, the invention has the beneficial effects that:
the spectral effect of the micro-nano optical fiber coupler is highly sensitive to the environment refractive index of the micro-nano optical fiber optical near-field coupling region, so that the sensor has ultrahigh response sensitivity to acoustic wave signals, and can realize real-time detection of weak acoustic wave signals. In addition, the micro-nano optical fiber coupler sensing structure has strong flexibility, and the response sensitivity and the measuring range of the sensor to sound waves can be adjusted by adjusting the diameter and the coupling length of the two optical fibers in the coupling area.
The vibrating diaphragm can respond to weak sound wave signals in a wide frequency range and transmit the sound wave signals to the gas cavity, so that the sensor has sound wave response characteristics in the wide frequency range and can cover infrasound, audible sound and ultrasound. Meanwhile, the normal vibration damping of the vibrating diaphragm is obviously smaller than the tangential vibration damping, so that the sound wave sensor has obvious directivity, noise interference in a non-acquisition direction can be effectively reduced, and the signal-to-noise ratio of a sound wave signal to be detected is improved.
The vibrating diaphragm and the airtight gas cavity structure play roles in sound wave acquisition and amplification, and are beneficial to improving the sound wave response sensitivity of the device. Meanwhile, the sealed gas cavity realizes the encapsulation of the micro-nano optical fiber coupler, so that the optical sensitive part is prevented from being polluted by dust or moisture, the measurement errors caused by environmental factors such as air flow disturbance, humidity change and the like are reduced, and the robustness of the micro-nano optical fiber coupler to acoustic wave sensing is improved.
The invention has the advantages of ultra-high sensitivity, real-time response, compact structure, low cost and the like, and has wide application prospect in the fields of ultrasonic monitoring, industrial nondestructive testing, robot navigation and the like.
Drawings
In order to more clearly describe the technical solutions of the embodiments of the present invention, the following description is made with reference to the accompanying drawings of the related technical solutions of the embodiments of the present invention.
FIG. 1 is a schematic diagram of the general structure of an acoustic wave sensor based on a micro-nano fiber coupler according to the present invention;
FIG. 2 is a schematic diagram of an exploded view of an acoustic wave sensor based on a micro-nano fiber coupler according to the present invention;
FIG. 3 is a schematic top view of an acoustic wave detection system constructed from an acoustic wave sensor based on a micro-nano fiber coupler in an embodiment of the present invention;
FIG. 4 is a schematic side view of an acoustic wave detection system constructed from an acoustic wave sensor based on a micro-nano fiber coupler in an embodiment of the invention;
FIG. 5 is a schematic view of a structure of a fiber fixing jig for manufacturing a micro-nano fiber coupler according to an embodiment of the present invention;
FIG. 6 is a schematic view of a gas cavity mold according to the present invention;
FIG. 7 is a flow chart of a method of making a micro-nano fiber optic coupler based acoustic wave sensor in accordance with the present invention.
In the figure: the device comprises a 1-micro-nano optical fiber coupler, a 2-gas cavity, a 3-vibrating membrane, a 4-substrate, a 5= -laser light source, a 6-photoelectric detector and a 7-oscilloscope.
Detailed Description
The invention is further described below with reference to the drawings and examples.
As shown in fig. 1 and 2, the structure of the acoustic wave sensor in the embodiment includes:
comprises a substrate 4 as a base of the acoustic wave sensor;
comprising a gas chamber 2 arranged on a substrate 4, having a relatively closed gas chamber inside;
the micro-nano optical fiber coupler comprises a micro-nano optical fiber coupler 1, wherein the micro-nano optical fiber coupler is provided with an optical sensitive part, and the optical sensitive part is arranged in a gas chamber of a gas cavity 2 and is in direct contact with gas in the gas chamber;
comprising a diaphragm 3 arranged on one side surface of a gas chamber 2, and a gas in the gas chamber 2 is in direct contact. The diaphragm 3 is a diaphragm capable of converting external sound waves into self-vibrations and further driving gas vibrations in the gas chamber of the gas chamber 2, and the vibration of the diaphragm 3 can drive gas fluctuation movements in the gas chamber 2.
The gas cavity 2 is a solid block with a through groove which is vertically communicated in the middle, and the through groove is used as a gas chamber space of the gas cavity 2. Only two ports are arranged at two ends of the through groove and are respectively covered by the vibrating membrane 3 and the substrate 4, so that a relatively closed space is formed in the air chamber and filled with air.
In the specific implementation, the upper end face and the lower end face of the gas cavity 2 are respectively and tightly attached to the vibrating membrane 3 and the substrate 4 to form a closed space, and the gas is filled in the cavity.
The micro-nano optical fiber coupler 1 is arranged through the gas cavity 2 and the gas chamber thereof, and the optical sensitive part is positioned in the middle of the gas chamber of the gas cavity 2.
The micro-nano optical fiber coupler 1 has a tapered region part with a thinner and thinnest middle diameter, and the diameter of the tapered region part is thinner than that of other parts, so that the tapered region part is used as an optical sensitive part.
The substrate 4, the gas cavity 2 and the vibrating membrane 3 are bonded to form a closed gas chamber, and an optical near-field coupling structure formed by the tapered region of the micro-nano optical fiber coupler 1 is arranged in the closed gas chamber.
The micro-nano optical fiber coupler 1 is formed by arranging at least two tapered optical fibers in parallel and side by side, and tapered area parts of the tapered optical fibers are tightly attached into a whole. And, the refractive index of the substrate 4 should be lower than that of the tapered fiber in the micro-nano fiber coupler 1.
The micro-nano optical fiber coupler 1 is manufactured by fusing and stretching two identical common optical fibers with coating removed, wherein the two common optical fibers are abutted together, a tapered region part is formed at the taper part of the middle part of each optical fiber, the common optical fibers are processed into tapered optical fibers, and the tapered region parts of the two tapered optical fibers are tightly contacted with each other to form an optical near-field coupling structure as an optical sensitive part.
For preparing a tapered optical fiber, the tapered region is formed at the taper part of the middle part of the optical fiber by melting and stretching.
For preparing two tapered optical fibers, the two tapered optical fibers are manufactured through fusion drawing, tapered area parts are formed at the tapered parts of the middle parts of the two optical fibers, and the tapered area parts of the two tapered optical fibers are tightly attached together all the time when the two tapered optical fibers are fused and drawn.
In specific implementation, when the micro-nano optical fiber coupler 1 is manufactured, two tapered optical fibers can be prepared and obtained respectively, and then the tapered area parts of the two tapered optical fibers are connected together through micro-nano operation under microscope observation.
In particular embodiments, the optical near-field coupling structure/optical sensing portion of the micro-nano fiber coupler 1 is disposed above the substrate 4.
In a specific implementation, the optical fibers of the micro-nano optical fiber coupler 1 can be arranged in a straight line direction or in an S-shaped mode. As shown in fig. 3 and 4, in the implementation, the acoustic wave detection system formed by the acoustic wave sensor includes:
the acoustic wave sensor comprises the acoustic wave sensor;
the device comprises at least one group of optical detection assemblies, each group of laser light source 5, a photoelectric detector 6 and an oscilloscope 7, wherein the laser light source 5 is connected with one end of a micro-nano optical fiber coupler 1 in the acoustic wave sensor, the other end of the micro-nano optical fiber coupler 1 is connected with the photoelectric detector 6, and meanwhile the photoelectric detector 6 is electrically connected with the oscilloscope 7.
The laser light source 5 is used for sending laser light signals to the optical fiber of the micro-nano optical fiber coupler 1, the photoelectric detector 6 is used for detecting the light signals transmitted from the optical fiber of the micro-nano optical fiber coupler 1, the oscilloscope 7 is used for detecting the light intensity of the light signals transmitted from the photoelectric detector 6 and displaying the light intensity, and then the real-time acquisition and display of the signals can be realized finally.
Preferably, the input end of the micro-nano optical fiber coupler 1 is connected with a laser light source 5 with a narrow bandwidth, and the output end of the micro-nano optical fiber coupler 1 is connected with a photoelectric detector 6.
The laser source 5 is a narrow bandwidth laser source, and may specifically be a 1550nm laser source.
In a specific implementation, one set of optical detection components or two sets of optical detection components or more sets of optical detection components may be provided.
When a set of optical detection components is provided, the set of optical detection components is connected to the acoustic wave sensor wherein the input end of only one optical fiber of the micro-nano fiber coupler 1 and the output end of only one optical fiber, i.e. wherein the input end of only one optical fiber of the micro-nano fiber coupler 1 is connected to the laser light source 5 and the other end is connected to the photodetector 6. When two groups of optical detection assemblies are arranged, the two groups of optical detection assemblies are respectively connected to two ends of each of the two optical fibers of the micro-nano optical fiber coupler 1 in the acoustic wave sensor, namely, one group of optical detection assemblies is connected to two ends of one optical fiber of the micro-nano optical fiber coupler 1, and the other group of optical detection assemblies is connected to two ends of the other optical fiber of the micro-nano optical fiber coupler 1.
The detection process and principle in the specific implementation of the invention are as follows:
the surface of the closed gas cavity 2, which is opposite to the plane of the micro-nano optical fiber coupler 1, is covered with the vibrating membrane 3, and the vibrating membrane 3 can receive the sound wave signals to generate vibration and convert the received sound wave signals into the vibration of the gas in the gas cavity 2, so that the refractive index of the gas near the optical sensitive part of the micro-nano optical fiber coupler 1 is changed.
The vibration film 3 receives sound waves and converts the sound waves into vibration of the vibration film, so that the refractive index of gas in the communicated closed gas cavity 2 changes, the change of the refractive index of the gas influences optical signals transmitted in the optical fiber through an evanescent field of the sensitive part of the optical fiber, and the light splitting ratio output by the micro-nano optical fiber coupler 1 is changed.
Finally, the real-time detection of the sound wave signals can be realized by detecting the light intensity change of the output end of the micro-nano optical fiber coupler 1.
More specifically, when the optical signal passes through the tapering region of the tapering optical fiber of the micro-nano optical fiber coupler 1, the optical signal is outwards diffused to form an evanescent field outside the optical fiber, and the change of the refractive index of the gas caused by the vibration of the gas outside the optical fiber at the tapering region can influence the evanescent field and further influence the optical signal transmission through the tapering region, so that the optical signal finally output from the tapering optical fiber is changed.
The embodiment of the invention is as follows:
example 1
The acoustic wave sensor provided in this embodiment includes a micro-nano fiber coupler 1, a gas cavity 2, a diaphragm 3, and a substrate 4. The substrate 4 is used as a bottom surface, the vibrating membrane 3 is used as a top surface, the vibrating membrane 3 and the substrate 4 are respectively and closely arranged on the upper end surface and the lower end surface of the gas cavity 2 and are closely attached to form a gas chamber of a closed space, and the gas chamber is filled with gas.
The gas cavity 2 is arranged above the substrate 4, and the gas cavity 2 is internally provided with a relatively closed gas chamber, and the micro-nano optical fiber coupler 1 is provided with a tapered region part with a middle diameter thinner than other parts as an optical sensitive part, wherein the diameter of the tapered region part is thinner than that of the other parts, and the optical sensitive part is arranged in the gas cavity 2.
Specifically, the micro-nano optical fiber coupler 1 is formed by arranging two tapered optical fibers in parallel and side by side, and tapered area parts of the two tapered optical fibers are closely attached into a whole. And, the refractive index of the substrate 4 is lower than that of the tapered optical fiber in the micro-nano optical fiber coupler 1.
The optical fiber fixing fixtures 8 and 9 for preparing the micro-nano optical fiber coupler 1 formed by two tapered optical fibers are shown in fig. 5, wherein two arc-shaped guide rail grooves are respectively arranged on the optical fiber fixing fixtures 8 and 9. Two optical fibers 10 and 11 such as silica optical fibers with coating layers removed are fixed on the arc-shaped guide rail grooves, and the optical fibers 10 and 11 are contacted and attached in the middle areas of the optical fiber fixing fixtures 8 and 9. The middle region of the optical fibers is heated and the two optical fibers are fused and tapered, so that the part of the optical fibers in the middle of the optical fiber fixing fixtures 8 and 9 is gradually thinned to form a tapered region part. Because the fused biconical taper parts of the two optical fibers are attached side by side, the fused biconical taper parts of the two optical fibers form a tightly attached whole. The acoustic wave detection system provided in this embodiment includes the above-mentioned acoustic wave sensor and a set of optical detection assembly, and this set of optical detection assembly includes laser light source 5, photoelectric detector 6 and oscilloscope 7, and laser light source 5 with the input of only an optic fibre of the optical fiber coupler 1 that receives a little in the acoustic wave sensor receives, the output of only an optic fibre of optical fiber coupler 1 receives with photoelectric detector 6 and connects, and photoelectric detector 6 and oscilloscope 7 electricity are connected simultaneously.
The laser light source 5 is used for sending laser light signals to the optical fiber of the micro-nano optical fiber coupler 1, the photoelectric detector 6 is used for detecting the light signals transmitted from the optical fiber of the micro-nano optical fiber coupler 1, the oscilloscope 7 is used for detecting the light intensity of the light signals transmitted from the photoelectric detector 6 and displaying the light intensity, and then the real-time acquisition and display of the signals can be realized finally.
Preferably, the input end of the micro-nano optical fiber coupler 1 is connected with a laser light source 3 with a narrow bandwidth, and the output end of the micro-nano optical fiber coupler 1 is connected with a photoelectric detector 6.
In the present embodiment, the gas chamber 2 is made of PDMS, the substrate 4 is made of quartz glass coated with PDMS, the diaphragm 3 is made of PET, and the laser light source 5 is made of a narrow bandwidth laser light source having a wavelength of 1550nm, but is not limited thereto.
The acoustic wave sensor and the acoustic wave detection system based on the micro-nano optical fiber coupler are prepared according to the following method processes:
1. and (3) stripping coating layers of the two silica optical fibers with the same length, and then placing the two silica optical fibers on a guide rail groove of an optical fiber fixing clamp side by side for fixing, so that the tapered area areas of the two optical fibers which are heated and melted subsequently are ensured to be horizontal and contacted with each other, and the area of the two optical fibers from which the coating layers are stripped is heated and melted by using hydrogen flame.
One end of the same side of the two optical fibers is respectively connected with a 1550nm laser light source, and the other end of the same side of the two optical fibers is respectively connected with a photoelectric detector. The two photodetectors are electrically connected with the oscilloscope to read and display the transmittance of the two optical fibers in real time.
And judging the coupling state of the prepared micro-nano optical fiber coupler by observing the transmittance change of the two optical fibers.
Simultaneously stretching two optical fibers at constant speed along the two sides of the axial direction of the optical fibers,
when the transmittance of the two optical fibers is observed on the oscilloscope to obviously cross and oscillate in time sequence, the hydrogen flame is turned off, the optical fiber stretching is stopped, and the required micro-nano optical fiber coupler is obtained.
The silica fiber used in this example is SMF-28E type single mode fiber, the length of the stripped coating region is about 2cm, the diameter of the micro-nano fiber at the tapered region is about 1 μm, and the length of the coupling region is about 1cm.
2. The PDMS (polydimethylsiloxane) prepolymer and the curing agent are fully mixed into PDMS solution according to the volume ratio of 10:1, the PDMS solution with the volume of 1ml is evenly dripped on a quartz glass slide, and then the PDMS solution is heated at 80 ℃ for 10min to be cured into a film, so that the substrate covered with the PDMS film is obtained. The thickness of the PDMS film was about 500 μm.
3. Transferring the micro-nano optical fiber coupler onto a substrate covered with a PDMS film, so that the tapered region of the micro-nano optical fiber is tightly attached to the PDMS film and placed.
4. The PDMS solution was poured into a gas cavity mold as shown in fig. 6, which contains rectangular bosses inside the mold, the dimensions of which correspond to the dimensions of the gas cavity of the acoustic wave sensor. And after the PDMS solution is completely filled in the mold, heating at 80 ℃ for 10min to solidify the PDMS, and then stripping the PDMS from the mold to obtain the gas cavity. The height of the gas cavity is about 2mm.
5. And installing the PDMS gas cavity right above the micro-nano optical fiber coupler, ensuring that the coupling area of the micro-nano optical fiber coupler is completely positioned in the gas cavity, and simultaneously completely attaching the gas cavity to the contact plane of the substrate.
6. A PET (polyethylene terephthalate) film was used as the diaphragm, and the thickness was about 10. Mu.m. And flatly attaching the vibrating diaphragm to a plane of one side of the opening of the PDMS gas cavity opposite to the substrate, so as to ensure that the opening of the gas cavity is completely covered by the PET film, and the contact planes of the opening and the PET film are completely attached. Thus, the preparation of the acoustic wave sensor based on the micro-nano optical fiber coupler is completed. The single optical fiber input end of the micro-nano optical fiber coupler is connected with a 1550nm laser light source, the single optical fiber output end of the micro-nano optical fiber coupler is connected with a photoelectric detector, and the photoelectric detector is electrically connected with an oscilloscope and used for reading and displaying transmittance signals of the micro-nano optical fiber coupler in real time. When the vibration membrane vibrates due to the sound wave signals, the transmittance of the micro-nano optical fiber coupler correspondingly changes, so that the real-time detection of the sound wave signals is realized. Driving electroacoustic transducers with signal generators to generate 5Hz, 1×10 respectively 3 Hz、3×10 4 When the infrasonic wave, the sound wave and the ultrasonic wave are transmitted in the Hz mode, the sound wave sensor and the system can generate obvious response, and the oscillograph displays the sound wave signals with corresponding frequencies in real time.
Therefore, the acoustic wave sensor has the advantages of high sensitivity, strong robustness and the like.
Example 2
Unlike example 1, the gas chamber 2 was made of epoxy material, two tapered optical fibers were each provided with one optical detection assembly, and the photodetectors of each optical detection assembly shared a multichannel oscilloscope.
In the embodiment, the micro-nano optical fiber coupler 1 is formed by two tapered optical fibers, and the gas cavity 2 is formed by mixing epoxy resin A glue and epoxy resin B glue according to a volume ratio of 5:2, curing in a gas cavity mold and demolding. The diaphragm 3 is made of PET material, and the substrate 4 is made of quartz glass material covered with PDMS film. The single optical fiber input end of the micro-nano optical fiber coupler is connected with a 1550nm laser source, the two optical fiber output ends of the micro-nano optical fiber coupler are respectively connected with photoelectric detectors, and the two photoelectric detectors are electrically connected with a multichannel oscilloscope at the same time and used for reading and displaying transmittance signals of the micro-nano optical fiber coupler in real time. When the vibration membrane vibrates due to the sound wave signals, the light splitting ratio of the micro-nano optical fiber coupler changes, the transmittance of the two optical fiber output ends of the micro-nano optical fiber coupler correspondingly changes, and the real-time detection of the sound wave signals can be realized by reading the signal changes of the two output ends through the oscilloscope. Driving electroacoustic transducers with signal generators to generate 5Hz, 1×10 respectively 3 Hz、3×10 4 When the infrasonic wave, the sound wave and the ultrasonic wave are transmitted in the Hz mode, the sound wave sensor and the system can generate obvious response, and the oscillograph displays the sound wave signals with corresponding frequencies in real time.
In addition, since the two tapered fibers are arranged in a common path, the two fibers have the same response to ambient noise. Assuming that the transmittance of the two optical fiber output ends is T1 and T2 respectively, the attenuation or elimination of the environmental low-frequency noise can be realized through the data processing physical quantity (T1-T2)/(T1 + T2), so that the detection of the acoustic wave signal with lower detection limit is realized.
Example 3
Unlike embodiment 1, the vibration film 3 is made of PMMA, a plurality of tapering optical fibers are arranged in the micro-nano optical fiber coupler 1, an optical detection component is connected to the input end and the output end of each tapering optical fiber of the plurality of tapering optical fibers, and the photodetectors of the optical detection components share a multichannel oscilloscope. In this embodiment, the micro-nano optical fiber coupler 1 is composed of four tapered optical fibers, and the gas cavity 2 is made by curing and demolding PDMS in a gas cavity mold. The diaphragm 3 is made of PMMA, and the substrate 4 is made of quartz glass covered with a PDMS film. The 1550nm laser light source is connected to the input end of each optical fiber of the micro-nano optical fiber coupler, the photoelectric detectors are respectively connected to the output end of each optical fiber of the micro-nano optical fiber coupler, and the photoelectric detectors are electrically connected with the multichannel oscilloscope at the same time and used for reading and displaying the transmittance signals of the micro-nano optical fiber coupler in real time. When the vibration membrane vibrates due to the sound wave signals, the light splitting ratio of the micro-nano optical fiber coupler changes, the transmittance of each optical fiber output end of the micro-nano optical fiber coupler correspondingly changes, and the real-time detection of the sound wave signals can be realized by reading the signal changes of each output end through the oscilloscope. Driving electroacoustic transducers with signal generators to generate 5Hz, 1×10 respectively 3 Hz、3×10 4 When the infrasonic wave, the sound wave and the ultrasonic wave are transmitted in the Hz mode, the sound wave sensor and the system can generate obvious response, and the oscillograph displays the sound wave signals with corresponding frequencies in real time. Because the micro-nano optical fiber coupler consists of a plurality of tapered optical fibers, the tapered optical fibers are arranged in a common way, therebyThe output ends of the plurality of tapered optical fibers can be connected into different systems to realize synchronous detection of the acoustic wave signals.
Example 4
Unlike example 1, the gas chamber 2 was made of an epoxy resin material, and the diaphragm 3 was made of a PMMA material. Two tapered optical fibers are arranged in the micro-nano optical fiber coupler 1, and the tapered area part of the prepared micro-nano optical fiber coupler 1 is arranged on a substrate in a gas cavity in an S-shaped mode. The two tapered optical fibers are connected with an optical detection assembly, and the photoelectric detectors of the optical detection assemblies share a multichannel oscilloscope.
In the embodiment, the gas cavity 2 is prepared by mixing epoxy resin A glue and epoxy resin B glue according to the volume ratio of 5:2, solidifying in a gas cavity mould and demoulding. The diaphragm 3 is made of PMMA, and the thickness of the PMMA film is 10 μm. The substrate 4 is made of quartz glass material covered with a PDMS film. The micro-nano optical fiber coupler 1 consists of two tapered optical fibers, and the tapered area part of the micro-nano optical fiber coupler is arranged on a substrate connected with a gas cavity in an S-shaped mode, so that the action area of an optical sensitive part is increased, and the detection of sound wave signals with higher sensitivity can be realized. The single optical fiber input end of the micro-nano optical fiber coupler is connected with a 1550nm laser source, the two optical fiber output ends of the micro-nano optical fiber coupler are respectively connected with photoelectric detectors, and the two photoelectric detectors are electrically connected with a multichannel oscilloscope at the same time and used for reading and displaying transmittance signals of the micro-nano optical fiber coupler in real time. When the vibration membrane vibrates due to the sound wave signals, the light splitting ratio of the micro-nano optical fiber coupler changes, the transmittance of the two optical fiber output ends of the micro-nano optical fiber coupler correspondingly changes, and the real-time detection of the sound wave signals can be realized by reading the signal changes of the two output ends through the oscilloscope. Driving electroacoustic transducers with signal generators to generate 5Hz, 1×10 respectively 3 Hz、3×10 4 When the infrasonic wave, the sound wave and the ultrasonic wave are transmitted in the Hz mode, the sound wave sensor and the system can generate obvious response, and the oscillograph displays the sound wave signals with corresponding frequencies in real time. In addition, since the two tapered fibers are arranged in a common path, the two fibers have the same response to ambient noise.Assuming that the transmittance of the two optical fiber output ends is T1 and T2 respectively, the attenuation or elimination of the environmental low-frequency noise can be realized through the data processing physical quantity (T1-T2)/(T1 + T2), so that the detection of the acoustic wave signal with lower detection limit is realized.
A flow chart of a method for preparing the acoustic wave sensor based on the micro-nano optical fiber coupler is shown in fig. 7.
The foregoing detailed description is provided to illustrate the present invention and not to limit the invention, and any modifications and changes made to the present invention within the spirit of the present invention and the scope of the appended claims fall within the scope of the present invention.
The foregoing description is only of the preferred embodiments of the invention, and all changes and modifications that come within the meaning and range of equivalency of the structures, features and principles of the invention are therefore intended to be embraced therein.
Claims (10)
1. An acoustic wave sensor based on a micro-nano optical fiber coupler is characterized in that:
comprises a substrate (4) as a base of the acoustic wave sensor;
comprises a gas cavity (2) arranged on a substrate (4) and having a relatively closed gas chamber inside;
comprises a micro-nano optical fiber coupler (1) with an optical sensitive part, wherein the optical sensitive part is arranged in a gas cavity (2);
comprising a diaphragm (3) arranged on one side surface of a gas chamber (2), the gas in the gas chamber (2) being in direct contact.
2. The acoustic wave sensor based on the micro-nano fiber coupler according to claim 1, wherein: the gas chamber of the gas cavity (2) is only provided with two openings, and the two openings are respectively covered by the vibrating membrane (3) and the substrate (4), so that a relatively closed space is formed in the gas chamber and filled with gas.
3. The acoustic wave sensor based on the micro-nano fiber coupler according to claim 1, wherein: the micro-nano optical fiber coupler (1) is arranged through the gas cavity (2) and enables the optical sensitive part to be positioned in the middle of the gas chamber of the gas cavity (2).
4. A micro-nano fiber coupler based acoustic wave sensor according to claim 1 or 3, wherein: the micro-nano optical fiber coupler (1) is provided with a tapered area part with a middle diameter thinner than other parts, and the tapered area part is used as an optical sensitive part.
5. The acoustic wave sensor based on the micro-nano fiber coupler according to claim 1, wherein: the micro-nano optical fiber coupler (1) is formed by arranging at least two tapered optical fibers in parallel and side by side, and tapered area parts of the tapered optical fibers are tightly attached into a whole.
6. The acoustic wave sensor based on the micro-nano fiber coupler according to claim 1, wherein: the refractive index of the substrate (4) is lower than that of the tapered optical fiber in the micro-nano optical fiber coupler (1).
7. The acoustic wave sensor based on the micro-nano fiber coupler according to claim 1, wherein: the vibrating membrane (3) can convert an external sound wave signal into self vibration so as to drive gas in the gas chamber of the gas cavity (2) to vibrate.
8. An acoustic wave detection system based on a micro-nano optical fiber coupler is characterized in that:
comprising the acoustic wave sensor of claim 1;
the device comprises at least one group of optical detection assemblies, each group of optical detection assemblies comprises a laser light source (5), a photoelectric detector (6) and an oscilloscope (7), one end of a micro-nano optical fiber coupler (1) in the acoustic wave sensor is connected with the laser light source (5), the other end of the micro-nano optical fiber coupler (1) is connected with the photoelectric detector (6), and meanwhile the photoelectric detector (6) is electrically connected with the oscilloscope (7).
9. The acoustic wave detection system based on the micro-nano fiber coupler according to claim 8, wherein:
each comprises a group of optical detection components, and the optical detection components are connected to a single optical fiber input end and a single optical fiber output end of a micro-nano optical fiber coupler (1) in the acoustic wave sensor.
10. The acoustic wave detection system based on the micro-nano fiber coupler according to claim 8, wherein:
the micro-nano optical fiber coupler comprises two groups of optical detection assemblies, wherein the micro-nano optical fiber coupler (1) comprises two optical fibers, and the two groups of optical detection assemblies are respectively connected to two optical fiber input ends and two optical fiber output ends of one micro-nano optical fiber coupler (1) in the acoustic wave sensor.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118010670A (en) * | 2024-02-01 | 2024-05-10 | 武汉理工大学 | An infrared micro-nano optical fiber sensor |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110187868A1 (en) * | 2007-08-27 | 2011-08-04 | Canon Kabushiki Kaisha | Acoustic-wave sensor, acoustic-wave sensor array, and ultrasonic imaging apparatus |
| CN102879082A (en) * | 2012-09-29 | 2013-01-16 | 华中科技大学 | Acoustic frequency detector and acoustic frequency detecting system with multi-mode coupler |
| US20140352442A1 (en) * | 2013-06-03 | 2014-12-04 | Macau University Of Science And Technology | Vibration Detection System Based on Biconical Tapered Fiber and the Method thereof |
| CN106019478A (en) * | 2016-05-12 | 2016-10-12 | 西安交通大学 | High-sensitivity pyrometric cone coupling micro-nano optical fiber ultrasonic detection system and coupler manufacturing method thereof |
| CN110220584A (en) * | 2019-06-06 | 2019-09-10 | 中国科学院电子学研究所 | Optics acoustic sensor and optics sonic transducer including it |
| CN115153469A (en) * | 2022-07-22 | 2022-10-11 | 东北石油大学 | Human body multi-parameter monitoring device based on self-mixing interference and micro-nano optical fiber |
-
2023
- 2023-06-28 CN CN202310774542.3A patent/CN116818084A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110187868A1 (en) * | 2007-08-27 | 2011-08-04 | Canon Kabushiki Kaisha | Acoustic-wave sensor, acoustic-wave sensor array, and ultrasonic imaging apparatus |
| CN102879082A (en) * | 2012-09-29 | 2013-01-16 | 华中科技大学 | Acoustic frequency detector and acoustic frequency detecting system with multi-mode coupler |
| US20140352442A1 (en) * | 2013-06-03 | 2014-12-04 | Macau University Of Science And Technology | Vibration Detection System Based on Biconical Tapered Fiber and the Method thereof |
| CN106019478A (en) * | 2016-05-12 | 2016-10-12 | 西安交通大学 | High-sensitivity pyrometric cone coupling micro-nano optical fiber ultrasonic detection system and coupler manufacturing method thereof |
| CN110220584A (en) * | 2019-06-06 | 2019-09-10 | 中国科学院电子学研究所 | Optics acoustic sensor and optics sonic transducer including it |
| CN115153469A (en) * | 2022-07-22 | 2022-10-11 | 东北石油大学 | Human body multi-parameter monitoring device based on self-mixing interference and micro-nano optical fiber |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118010670A (en) * | 2024-02-01 | 2024-05-10 | 武汉理工大学 | An infrared micro-nano optical fiber sensor |
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