A fiber optic ultrasonic endoscope with integrated side-to-side transmission and reception and its preparation method

Abstract

The present invention discloses a fiber-optic ultrasonic endoscope with integrated lateral transmission and reception and a preparation method, which belongs to the field of ultrasonic endoscopic imaging. It comprises a double-clad optical fiber, an excitation film, a dielectric mirror, and a sensing film. By etching part of the inner cladding of the optical fiber into a concave spherical surface and coating it with an excitation film, the excitation light transmitted in the inner cladding is absorbed and focused ultrasonic waves transmitted laterally are excited. By etching part of the inner cladding and the core of the optical fiber and preparing it into a Fabry-Perot (F-P) cavity. When the ultrasonic signal transmitted laterally into the ultrasonic endoscope acts on the sensing film of the cavity, the effective refractive index of the sensing film and the F-P cavity length change, and the signal light in the core demodulates this change to complete the detection of ultrasonic waves. The present invention etches the inner cladding and coats it with an excitation film to achieve the excitation of laterally focused ultrasonic waves, etches an F-P cavity on the side of the optical fiber to achieve the lateral detection of ultrasonic waves, and thus forms a fiber-optic ultrasonic endoscope with integrated lateral transmission and reception.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic endoscopic imaging, and more specifically, relates to a lateral transceiver integrated optical fiber ultrasonic endoscope and a preparation method thereof. Background Art

[0002] Ultrasound, due to its excellent directionality, strong penetrating power, and ability to easily generate concentrated sound energy, is now widely used in biomedical fields, particularly in endoscopic imaging. Fiber-optic ultrasound endoscopes leverage the properties of ultrasound to provide internal information about the object being examined, enabling adjustments to surgical strategies based on this information, improving surgical safety and success rates. The imaging principle is that an ultrasonic transducer emits an ultrasonic signal that propagates to a specific part of the object being examined. The signal is then reflected by the object and received by the transducer, which then demodulates the signal to obtain an image or structural information of the object being examined.

[0003] Compared with traditional piezoelectric ultrasonic devices, fiber optic ultrasonic endoscopes have the characteristics of small size, high sensitivity, good flexibility, and resistance to electromagnetic interference. Fiber optic ultrasonic endoscopes are composed of two types: fiber optic ultrasonic transmitters and ultrasonic detectors. The first type of ultrasonic transmitter is composed of light absorbing materials and thermal expansion materials. The main mechanism is thermal expansion after absorbing laser light. The light absorbing materials are currently mainly metal materials and carbon-based materials with high light absorption, such as gold, chromium, germanium, carbon black, carbon nanotubes, candle ash, etc. For thermal expansion materials, PDMS is widely used due to its high thermal expansion and transparency. The second type of ultrasonic detector obtains the ultrasonic signal to be measured by measuring the shape of the detector or the changes in its physical parameters caused by ultrasonic waves. At present, the main types of ultrasonic detectors are fiber grating type, Mach-Zehnder interferometer type, FP interferometer and microring resonator type.

[0004] Fiber-optic ultrasound endoscopes primarily image tissue laterally. However, the ultrasound transmitter in current fiber-optic endoscopes typically operates from the front end of the optical fiber, requiring additional components to steer the ultrasound for lateral imaging. Existing lateral ultrasound transmitters primarily transmit light within the fiber core, coupling the excitation light to the cladding through mechanical structural disruption or grating techniques. As a result, the excitation light energy is weak, resulting in a small ultrasound signal, which limits their application. Summary of the Invention

[0005] In response to the defects of the existing technology or the need for improvement, the purpose of the present invention is to provide a lateral transceiver integrated fiber optic ultrasonic endoscope and a preparation method, aiming to solve the problems of existing fiber optic endoscopes such as large size, small excitation ultrasonic signal, and complex system.

[0006] To achieve the above object, according to one aspect of the present invention, there is provided a lateral transceiver integrated fiber optic ultrasonic endoscope, comprising: a double-clad optical fiber, an excitation film, a dielectric mirror, and a sensing film;

[0007] The double-clad optical fiber includes a core, an inner cladding, and an outer cladding arranged from the inside out; the transmission mode of the core at the signal light wavelength is single mode, and is used for transmitting the signal light;

[0008] The inner cladding is multi-mode in transmission at the excitation light wavelength and is used for transmission of the excitation light; the signal light and the excitation light are bounded by the outer cladding; the inner cladding of the double-clad optical fiber, which is away from the optical fiber end face, is a concave spherical surface, and the excitation film is located on the surface of the concave spherical surface; the excitation film is coated on the surface of the concave spherical surface by a pulling method;

[0009] The inner cladding of the double-clad optical fiber, which is close to the end face of the optical fiber and in the same direction as the concave spherical surface, is recessed inwardly to the core to form an open microcavity;

[0010] The dielectric mirror and the sensing film are sequentially covered inside the microcavity to form an FP cavity;

[0011] When the fiber optic ultrasonic endoscope is used for lateral ultrasonic excitation, the excitation light is transmitted along the inner cladding of the double-clad optical fiber, and when the excitation light is transmitted to the excitation film, it is absorbed and generates a focused ultrasonic signal that propagates laterally;

[0012] When the fiber optic ultrasonic endoscope is used for lateral ultrasonic detection, the signal light is transmitted along the core of the double-clad optical fiber and reflected back to the double-clad optical fiber by the dielectric mirror as a detection signal. When the ultrasonic wave reflected by the object to be measured is transmitted laterally to the sensing film, the geometric displacement caused by the ultrasonic wave and the elastic-optic effect interact with each other, causing the FP cavity length and the effective refractive index of the sensing film to change, thereby changing the phase difference of the electric field between the two reflections of adjacent signal lights, thereby modulating the ultrasonic wave reflected by the object to be measured to the phase of the signal light reflected by the dielectric mirror, thereby changing the optical power of the signal light, and realizing lateral ultrasonic detection by detecting its optical power.

[0013] Preferably, the contact area between the excitation film and the excitation light is greater than 0.01 mm 2 , thereby increasing the sound pressure of the ultrasonic signal.

[0014] Preferably, the focal length of the concave spherical surface is 0.5 mm to 10 mm, and is used to excite laterally propagating ultrasonic waves and focus them on the object to be measured.

[0015] Preferably, the microcavity is precisely etched to a length of 5 μm to 200 μm using a femtosecond laser, so as to reduce the aperture size for detecting ultrasound and improve imaging resolution.

[0016] Preferably, the dielectric mirror is a dielectric thin film formed by alternately depositing two different inorganic materials with a refractive index of 1.2 to 2.5, and has a reflectivity of more than 97% for the wavelength of the signal light.

[0017] Preferably, the sensing film has an elastic coefficient greater than 10 -7 / RIU and a polymer material with a transmittance of more than 90% for the signal light wavelength, and a large elastic-optical coefficient is used to improve the sensitivity of ultrasonic detection.

[0018] Preferably, the signal light is a narrow linewidth laser, and the excitation light is a narrow pulsewidth pulse light or a modulated continuous light.

[0019] Preferably, the excitation film has a light absorption coefficient of more than 1.5 for the excitation light wavelength, and the specific surface area of ​​the light absorption material is 30m 2 g -1 The thermal expansion coefficient of the thermal expansion material is greater than 10 -4 / ℃, has rapid thermal diffusion and high thermal elastic expansion coefficient, and the light absorbing material and the thermal expansion material have a ratio of 1:2 to 1:10 with high photoacoustic conversion efficiency.

[0020] According to another aspect of the present invention, a method for preparing a lateral transceiver integrated fiber optic ultrasonic endoscope is provided, comprising the following steps:

[0021] In step S1, use a fiber stripper to remove the coating from a section of a double-clad optical fiber away from the fiber end face. Use a clean cloth dipped in alcohol and deionized water to wipe the bare fiber. A femtosecond pulse laser is then focused onto the top surface of the fiber. The platform is programmatically controlled to move in three dimensions until it scans the entire concave spherical surface at the preset focus. The resulting concave spherical surface is then cleaned with alcohol and deionized water.

[0022] S2, mixing the polymer obtained by mixing PDMS and a curing agent with carbon black according to a mass ratio, stirring the mixture evenly with a magnetic stirrer, and then placing the mixture in a vacuum drying oven to remove bubbles in the mixture.

[0023] S3, using a pulling machine to immerse the etched part of the optical fiber into a mixture of carbon black and PDMS, and slowly pull out the optical fiber, and then slowly move the optical fiber to a constant temperature drying oven to solidify to form an excitation film.

[0024] In step S4, use a clean cloth dipped in alcohol and deionized water to wipe the portion of the fiber end face coated with the mixture to remove the mixture. Use fiber strippers to strip the coating layer of the double-clad fiber where the mixture has been removed. Use a clean cloth dipped in alcohol and deionized water to wipe the bare fiber. A femtosecond pulse laser is then used to etch a microcavity in the same direction as the concave spherical surface, ensuring that the etching depth of the microcavity exceeds the lower surface of the fiber core. The resulting microcavity structure is then cleaned with alcohol and deionized water.

[0025] S5, using vacuum evaporation coating method to alternately deposit multiple layers of silicon dioxide and titanium dioxide on the inner surface of the optical fiber microcavity as a dielectric mirror.

[0026] In step S6, under a microscope, the ultrafine optical fiber obtained by oxyhydrogen flame tapering is dip-coated with a small amount of a high-elastic-optical-coefficient polymer material. The fiber is then mounted on a three-dimensional displacement platform and slowly moved to the microcavity structure. The polymer material is then filled into the microcavity, ensuring that the polymer material is higher than the top surface of the fiber core. The fiber is then slowly moved into a constant-temperature drying oven to solidify and form a sensing film. The dielectric mirror and sensing film together form the FP cavity, completing the fabrication of the fiber-optic ultrasound endoscope.

[0027] S7. Finally, the excitation light and narrow-linewidth laser are input into the multi-mode input end and single-mode input end of the double-clad coupler respectively using an optical circulator, and the light is further coupled to the fiber optic ultrasonic endoscope. A lateral transceiver integrated fiber optic ultrasonic endoscope is constructed in conjunction with a three-dimensional rotation translation stage and a signal processing and control system.

[0028] Compared with the prior art, the above technical solutions proposed by the present invention can achieve the following

[0029] Beneficial effects:

[0030] 1. The present invention provides a fiber-optic ultrasonic endoscope that can realize lateral transmission and reception in an integrated manner using a single optical fiber. A single double-clad optical fiber is used to realize ultrasonic transmission and ultrasonic detection functions, thereby reducing the size of the fiber-optic ultrasonic endoscope to about 245 μm, which can meet the needs of medical endoscopic imaging.

[0031] 2. The present invention utilizes the inner cladding of the optical fiber to transmit the excitation light and perform lateral excitation. Compared with the core of the optical fiber transmitting the excitation light and performing lateral excitation, it has greater light energy, thereby increasing the sound pressure of the ultrasonic wave.

[0032] 3. The present invention utilizes femtosecond laser etching technology to precisely and programmatically etch the inner cladding into a concave spherical structure with a focal length of 0.5mm-10mm, which is commonly used in ultrasonic endoscopes. The sound beam at the focus is narrow, which can achieve an ultrasonic focusing effect, thereby improving the lateral resolution of imaging.

[0033] 4. The present invention utilizes femtosecond laser etching to create a short microcavity, which can reduce aperture size and improve imaging resolution. The microcavity structure, in contact with media such as blood and water, can directly detect lateral ultrasound signals, making it suitable for applications involving active lateral detection.

[0034] 5. The present invention forms an FP cavity by preparing a dielectric mirror and filling it with a polymer with a large elasto-optic coefficient, and utilizes the dual effects of the elasto-optic effect and the change in the geometric cavity length to achieve a highly sensitive ultrasonic detection function.

[0035] 6. The fiber optic ultrasonic endoscope and preparation method provided by the present invention have the advantages of high sensitivity, good stability, simple preparation, low cost, and ease of practical application, and can be widely used in the field of medical endoscopic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic structural diagram of the lateral transceiver integrated fiber optic ultrasonic endoscope provided by the present invention;

[0037] Figure 2 This is a schematic diagram of the manufacturing process of the lateral transceiver integrated fiber optic ultrasonic endoscope provided by the present invention;

[0038] In all drawings, the same reference numerals are used to represent the same elements or structures, including: 1. double-clad optical fiber; 2. excitation light; 3. excitation film; 4. signal light; 5. dielectric mirror; 6. sensing film. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0040] Figure 1 FIG. 1 is a schematic diagram of the structure of the lateral transceiver integrated fiber optic ultrasonic endoscope of the present invention. Figure 1 As shown, the present invention proposes a lateral transceiver integrated fiber optic ultrasonic endoscope, comprising a double-clad optical fiber 1, an excitation film 3, a dielectric mirror 5, and a sensing film 6. The inner cladding of the double-clad optical fiber is used to transmit the excitation light 2, and the core is used to transmit the signal light 4. The portion of the inner cladding away from the end face of the optical fiber is etched into a concave spherical surface, and a mixture of carbon black and PDMS is applied to the concave spherical surface area by a pulling method as the excitation film 3. According to the photoacoustic effect, when the excitation light is transmitted to the concave spherical surface, a focused ultrasonic signal propagating laterally is generated. The portion of the inner cladding and the core near the end face of the optical fiber are etched into a microcavity, and the etching depth exceeds the lower surface of the core. A dielectric film with wavelength-selective transmittance is deposited on the inner surface of the microcavity as the dielectric mirror 5, and a polymer material is filled into the microcavity as the sensing film 6. The dielectric mirror 5 and the sensing film 6 constitute an FP cavity, which is subjected to the geometric displacement caused by the side-reflected ultrasonic signal and the interaction of the elasto-optical effect, causing the FP cavity length and the effective refractive index of the sensing film 6 to change, thereby changing the phase difference of the electric fields of two adjacent reflections of the signal light 4, thereby modulating the side-reflected ultrasonic signal to the phase of the signal light 4, resulting in a change in the intensity of the reflected light, and thus changing the optical power of the signal light 4.

[0041] Specifically, the fiber core has a diameter less than 10 microns, operates in a single-mode transmission mode, and transmits the signal light 4 within the fiber core. The inner cladding has a diameter greater than 10 microns, operates in a multimode transmission mode, and transmits the excitation light 2 within the inner cladding. Furthermore, the outer cladding is used to confine the excitation light 2 and the signal light 4.

[0042] Specifically, the core diameter is 9 microns, the inner cladding diameter is 105 microns, the outer cladding diameter is 125 microns, the input signal light 4 is a narrow linewidth laser, and the excitation light 2 is a pulse light or a modulated continuous light.

[0043] Specifically, the substrate of the excitation film 3 is precisely etched into a concave spherical surface with a preset focus by a programmed femtosecond laser to excite a focused ultrasonic signal that propagates laterally.

[0044] Specifically, the light absorbing material has a specific surface area of ​​30m 2 g -1 The carbon black has high light absorption at the excitation light wavelength, and the thermal elastic expansion coefficient of the polymer material is greater than 10 -4 / ℃, the excitation film 3 has high photoacoustic conversion efficiency and good adsorption properties with the concave spherical surface.

[0045] Specifically, the length of the optical fiber microcavity is 5um to 200um, and the dielectric mirror 5 is a dielectric film formed by alternating deposition of silicon dioxide and titanium dioxide, which has a reflectivity of more than 97% for the wavelength of the signal light 4 and has good adsorption properties with the optical fiber microcavity and the sensing film 6.

[0046] Specifically, the sensing film 6 has an elastic coefficient greater than 10 -7 / RIU and a polymer material with a transmittance of more than 90% for the signal light wavelength, which increases the response between ultrasound and the effective refractive index and improves the sensitivity of ultrasonic detection.

[0047] Furthermore, the present invention also proposes a method for preparing the above-mentioned lateral transceiver integrated fiber optic ultrasonic endoscope, such as Figure 2 As shown, the specific steps include:

[0048] In step S1, use a fiber stripper to remove the coating from a section of double-clad fiber 1, away from the fiber end face. Wipe the bare fiber with a clean cloth dipped in alcohol and deionized water. Then, focus a femtosecond pulse laser onto the fiber's top surface, and programmatically control the three-dimensional movement of the stage until it scans the entire concave spherical surface with a preset focal length of 2 mm. The resulting concave spherical structure is then cleaned with alcohol and deionized water.

[0049] S2, the next step is to prepare the excitation film 3, and mix the polymer with carbon black according to the mass ratio of PDMS and curing agent at 10:1, stir evenly with a magnetic stirrer, and then place it in a vacuum drying oven for 30 minutes to remove bubbles in the mixture.

[0050] S3: Use a pulling machine to immerse the etched part of the optical fiber into a mixture of carbon black and PDMS, let it stand for 2 minutes, and slowly pull out the optical fiber at a certain speed. Then, slowly move the optical fiber to a constant temperature drying oven for curing.

[0051] In step S4, use a clean cloth dipped in alcohol and deionized water to wipe the portion of the fiber end face coated with the mixture to remove the mixture. Use fiber strippers to strip the coating layer of the double-clad fiber where the mixture has been removed. Use a clean cloth dipped in alcohol and deionized water to wipe the bare fiber. A femtosecond pulse laser is then used to etch a microcavity in the same direction as the concave spherical surface, ensuring that the etching depth of the microcavity exceeds the lower surface of the fiber core. The resulting microcavity structure is then cleaned with alcohol and deionized water.

[0052] S5, using a vacuum evaporation coating method to alternately deposit multiple layers of silicon dioxide and titanium dioxide on the inner surface of the optical fiber microcavity to serve as a dielectric mirror 5.

[0053] To further illustrate, the dielectric mirror 5 is a dielectric film formed by alternating multiple layers of silicon dioxide and titanium dioxide. It is a periodically refractive index modulated structure that can produce high reflectivity for light of a specific wavelength. By designing the parameters of the dielectric film, it has a reflectivity of more than 97% for the wavelength of the signal light 4.

[0054] In step S6, a 10:1 ratio of PDMS and curing agent is mixed using a magnetic stirrer and then placed in a vacuum drying oven to remove any bubbles. Under a microscope, the ultrafine optical fiber obtained by oxyhydrogen flame tapering is dipped in a small amount of PDMS. The fiber is then mounted on a 3D displacement platform and slowly moved to the microcavity structure. The PDMS is then filled into the microcavity, ensuring that the PDMS is higher than the top surface of the fiber core. The fiber is then slowly moved to a constant temperature drying oven to solidify and form the sensing film 6. The dielectric mirror 5 and sensing film 6 together form the FP cavity.

[0055] S7. Finally, the excitation light and narrow-linewidth laser are input into the multi-mode input end and single-mode input end of the double-clad coupler respectively using an optical circulator, and the light is further coupled to the fiber optic ultrasonic endoscope. A lateral transceiver integrated fiber optic ultrasonic endoscope is constructed in conjunction with a three-dimensional rotation translation stage and a signal processing and control system.

[0056] When the excitation light 2 is input into the ultrasonic endoscope, it irradiates the concave spherical surface, causing the excitation film 3 to increase in temperature and undergo thermoelastic expansion in the lateral direction, compressing the surrounding medium and generating focused ultrasound waves that are transmitted laterally.

[0057] The ultrasonic wave generated by the ultrasonic endoscope is reflected by the object to be measured and carries the imaging information of the object to be measured. The ultrasonic wave is directly detected laterally by the sensing film 6. The geometric displacement caused by the reflected ultrasonic signal and the interaction of the elastic-optical effect cause the FP cavity length and the effective refractive index of the sensing film 6 to change. In turn, the phase difference between the two adjacent reflected electric fields changes, resulting in a change in the intensity of the reflected light. The ultrasonic signal is detected by using a tunable laser through bevel edge demodulation.

[0058] When the signal light 4 is input to the ultrasonic endoscope, multi-beam interference occurs due to the effect of the FP cavity formed by the dielectric mirror 5 and the sensor film 6, forming interference light that is transmitted in the opposite direction along the optical fiber core. The intensity of the interference light is:

[0059]

[0060] Among them I i is the intensity of the incident signal light 4, R is the reflectivity of the single-side surface of the dielectric mirror 5 at the wavelength of the signal light 4, δ=4πnh / λ is the optical path of the signal light 4 reflected once on the two side surfaces of the dielectric mirror 5, n is the refractive index of the material of the sensing film 6, and h is the physical length between the two side surfaces of the dielectric mirror 5.

[0061] The ultrasonic wave to be measured acts on the sensing film 6, thereby changing the physical length h between the two sides of the dielectric mirror 5. Furthermore, due to the photoelastic effect, the ultrasonic wave to be measured acts on the sensing film 6, thereby changing the effective refractive index n of the sensing film 6. This in turn changes the optical path of the signal light 4, and the intensity of the interference light is modulated through multi-beam interference.

[0062] The all-fiber ultrasonic endoscope proposed in the present invention can be used for ultrasonic excitation and detection in different media environments, such as water, air and other liquid environments.

[0063] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lateral transceiver integrated fiber optic ultrasonic endoscope, characterized in that: It includes a double-clad optical fiber (1), an excitation film (3), a dielectric mirror (5), and a sensing film (6); The inner cladding of the double-clad optical fiber (1) that is away from the optical fiber end face is a concave spherical surface, and the excitation film (3) is located on the surface of the concave spherical surface; the inner cladding of the double-clad optical fiber (1) that is close to the optical fiber end face and in the same direction as the concave spherical surface is recessed inwardly to the fiber core to form an open microcavity, and the dielectric mirror (5) and the sensing film (6) are sequentially covered inside the microcavity to form an FP cavity; When the fiber optic ultrasonic endoscope is used for lateral ultrasonic excitation, the excitation light is transmitted along the inner cladding of the double-clad optical fiber (1), and when the excitation light is transmitted to the excitation film (3), it is absorbed, generating a focused ultrasonic signal that propagates laterally; When the fiber optic ultrasonic endoscope is used for lateral ultrasonic detection, the signal light is transmitted along the core of the double-clad optical fiber (1) and reflected by the dielectric mirror (5); when the ultrasonic wave reflected by the object to be detected is laterally transmitted to the sensing film (6), the FP cavity length and the effective refractive index of the sensing film (6) are changed, thereby changing the phase difference of the electric field of two adjacent reflections of the signal light, thereby modulating the ultrasonic wave reflected by the object to be detected to the phase of the signal light reflected by the dielectric mirror (5), thereby changing the optical power of the signal light, and realizing lateral ultrasonic detection by detecting its optical power.

2. The lateral transceiver integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The contact area between the excitation film (3) and the excitation light is greater than 0.01 mm 2 .

3. The lateral transceiver integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The focal length of the concave spherical surface is 0.5 mm to 10 mm.

4. The lateral transceiver integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The excitation film (3) includes a specific surface area of ​​30m 2 g -1 The above light absorbing material and thermal expansion material, the excitation film (3) has a light absorption rate of more than 90% for the excitation light wavelength.

5. The lateral transceiver integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The etching depth of the microcavity exceeds the lower surface of the core of the double-clad optical fiber (1).

6. The lateral transmitting and receiving integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The dielectric mirror (5) is a dielectric thin film formed by alternately depositing two different inorganic materials with a refractive index of 1.2 to 2.5, and has a reflectivity of more than 97% for the wavelength of the signal light.

7. The lateral transmitting and receiving integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The sensing film (6) is a polymer material having a transmittance of more than 90% for the wavelength of the signal light.

8. The lateral transceiver integrated fiber optic ultrasonic endoscope according to claim 1, characterized in that: The dielectric mirror (5) and the sensing film (6) on the inner surface of the microcavity together form an FP cavity, so that the signal light is repeatedly reflected on the two reflection surfaces of the FP cavity and multi-beam interference occurs in the optical fiber core.

9. A method for preparing a lateral transceiver integrated fiber optic ultrasonic endoscope according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, stripping a coating layer of a double-clad optical fiber (1) away from the optical fiber end face, focusing a femtosecond pulse laser on the upper surface of the stripped optical fiber, and scanning the entire concave spherical surface of the preset focus; S2, mixing the polymer of PDMS and curing agent with carbon black according to the mass ratio, stirring evenly and removing bubbles in the mixture; S3, immersing the etched portion of the optical fiber into the mixture and solidifying it to form an excitation film (3); S4, stripping a coating layer of a section of the double-clad optical fiber (1) near the optical fiber end face, etching a microcavity in the same direction as the concave spherical surface using a femtosecond pulse laser, and ensuring that the etching depth of the microcavity exceeds the lower surface of the optical fiber core; S5, alternately depositing multiple layers of silica and titania onto the inner surface of the optical fiber microcavity as a dielectric mirror (5); S6, dip-coating the ultra-fine optical fiber obtained by oxyhydrogen flame taper with a polymer material having a large elastic-optical coefficient, moving it to the microcavity and filling the polymer material in the microcavity, ensuring that the height of the polymer material is higher than the upper surface of the fiber core, and solidifying it to form a sensing film (6), forming an ultrasonic detection area.

Images