Pulsed Laser Detection Device

Abstract

The present disclosure relates to the technical field of optical instruments, and specifically provides a pulsed laser detection device, including: a first housing, inside which a photoacoustic conversion module and an acoustic-electric conversion module are provided; a second housing, disposed inside the first housing, and the photoacoustic conversion module is provided inside the second housing, including: an input aperture, configured to limit the diameter or spatial range of the incident laser entering the acoustic cavity; a diaphragm, disposed inside the second housing, and enclosing an acoustic cavity with the side wall of the second housing and the input aperture; a scattering cone, disposed inside the acoustic cavity, and configured to block the incident laser from directly irradiating the diaphragm. In the pulsed laser detection device, the photoacoustic conversion module includes a scattering cone, and the scattering cone can scatter the incident laser into a wide-angle distribution, blocking it from directly irradiating the surface of the diaphragm, which greatly improves the damage threshold of the detection device and promotes the beam to undergo multiple reflections inside the acoustic cavity, increasing the absorption efficiency of the acoustic cavity for laser energy.

Description

Technical Field

[0001] The present disclosure relates to the technical field of optical instruments, and more particularly, to a pulsed laser detection device. Background Art

[0002] Under the irradiation of a continuous laser pulse, a substance can effectively absorb the incident light energy and convert it into heat energy. This conversion process is based on the interaction between electrons and photons inside the substance, where the energy carried by photons is absorbed by electrons, converted into the kinetic energy of electron motion, and then the light energy is converted into heat energy through a non-radiative relaxation process. The heat energy causes the substance to thermally expand. If the light intensity of the pulsed light changes with time, periodic temperature fluctuations are generated, triggering mechanical vibrations in the surrounding medium, such as tissue or air, to form acoustic wave signals. This phenomenon is called the photoacoustic effect, which is the result of the conversion between light energy, heat energy, and acoustic energy.

[0003] Currently, the photoelectric probes for detecting pulsed lasers are mainly based on the photoelectric effect. The photoelectric effect refers to that when photons in a laser beam irradiate the surface of a pulsed laser detection device with a specific energy, if the energy of the photons is greater than or equal to the work function of the material, it will cause the valence electrons in the material to absorb the energy of the photons and transition to the conduction band to become free electrons. These free electrons start to move under the action of an external electric field to form an electric current, which is a direct manifestation of the photoelectric effect. In practical applications, by analyzing the current signal, researchers can accurately obtain the time characteristics of the laser pulse, including information such as pulse width, waveform, and repetition frequency. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a pulsed laser detection device for solving the technical problems in the related art. The specific solutions are as follows:

[0005] An embodiment of the present disclosure provides a pulsed laser detection device, including: a first housing with a photoacoustic conversion module and an acoustic-electric conversion module disposed therein; a second housing disposed inside the first housing, and the second housing is provided with the photoacoustic conversion module, including: an input diaphragm disposed on the side wall of the second housing and configured to limit the diameter or spatial range of the incident laser entering the acoustic cavity; a diaphragm disposed inside the second housing, enclosing an acoustic cavity with the side wall of the second housing and the input diaphragm; a scattering cone disposed in the acoustic cavity and configured to block the incident laser from directly irradiating the diaphragm.

[0006] In some embodiments, the scattering cone scatters the incident laser into a wide-angle distribution and is configured to cause the incident laser to reflect multiple times in the acoustic cavity.

[0007] In some embodiments, the scattering cone is a cone or a multi-pyramid.

[0008] In some embodiments, the pulsed laser detection device further includes: a support frame disposed inside the acoustic cavity and configured to keep the scattering cone stable within the acoustic cavity.

[0009] In some embodiments, the scattering cone is made of optical glass or quartz.

[0010] In some embodiments, the first housing is a sound-insulating cover that is wide-spectrum light-transmissive and is configured to reduce the influence of external noise.

[0011] In some embodiments, the acoustic-electric conversion module includes: a back plate disposed on a side of the diaphragm away from the scattering cone and configured to jointly form a capacitive structure with the diaphragm.

[0012] Wherein, in response to the diaphragm being vibrated by sound waves, the capacitance between the diaphragm and the back plate changes to achieve acoustic-electric conversion.

[0013] In some embodiments, the acoustic-electric conversion module further includes: an insulating gasket disposed between the diaphragm and the back plate and configured to separate the diaphragm from the back plate to form the capacitive structure.

[0014] In some embodiments, the acoustic-electric conversion module further includes: a transistor disposed on the inner wall of the first housing; a signal amplifier disposed inside the second housing and connected to the transistor and configured to amplify the electrical signal.

[0015] In some embodiments, the pulsed laser detection device further includes: a refrigeration air pump disposed outside the first housing, and both ends of the refrigeration air pump respectively penetrate the first housing and the second housing to extend into the acoustic cavity and are configured to dissipate heat from the acoustic cavity.

[0016] Compared with the related art, the above solution of the embodiments of the present disclosure has at least the following beneficial effects: The pulsed laser detection device provided by the present disclosure includes a photoacoustic conversion module and an acoustic-electric conversion module, and the photoacoustic conversion module includes a scattering cone. The scattering cone is disposed inside the acoustic cavity and can scatter the incident laser into a wide-angle distribution, preventing it from directly irradiating the surface of the diaphragm. This greatly improves the damage threshold of the detection device and promotes the laser beam to undergo multiple reflections inside the acoustic cavity, increasing the absorption efficiency of the acoustic cavity for laser energy. This design significantly reduces the detection threshold of the pulsed signal on the premise of ensuring the improvement of the diaphragm damage threshold, improves the detection dynamic range, and enables the pulsed laser detection device to have advantages such as a high damage threshold, a wide wavelength response range, a large dynamic range, and low cost.

[0017] It should be understood that the above general description and the following detailed description are only exemplary and explanatory and should not limit the present disclosure. Description of the Drawings

[0018] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0019] Figure 1 Schematic structural diagram of a pulsed laser detection device shown according to an exemplary embodiment.

[0020] Reference numerals:

[0021] First housing 100;

[0022] Second housing 200, acoustic cavity 201, input aperture 210, diaphragm 220, scattering cone 230;

[0023] Insulating gasket 240, back plate 250, transistor 260;

[0024] Signal amplifier 300, refrigeration air pump 400; pulsed laser detection device 1000. Detailed implementation manners

[0025] In order to make the objectives, technical solutions, and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present disclosure, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0026] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The singular forms "a", "the", and "said" used in the embodiments of the present disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. "Plural" generally includes at least two, and other quantifiers are similar.

[0027] It should be understood that although terms such as first, second, and third may be used in the embodiments of the present disclosure for description, these descriptions should not be limited to these terms. These terms are only used to distinguish the objects to be described. For example, without departing from the scope of the embodiments of the present disclosure, the first can also be called the second, and similarly, the second can also be called the first. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] It should be understood that the term "and / or" used herein is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this text generally indicates that the associated objects before and after are in an "or" relationship. The singular forms of "a", "the", and "said" are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0029] Furthermore, it can be further understood that the orientation or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "front", "rear", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this embodiment 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 thus should not be construed as a limitation of the present invention.

[0030] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected to" 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 or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. 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 circumstances.

[0031] Depending on the context, the words "if" and "when" as used herein can be interpreted as "when...", "while...", "in response to determining", or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detected (stated condition or event)" can be interpreted as "when determined", "in response to determining", "when detecting (stated condition or event)", or "in response to detecting (stated condition or event)".

[0032] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a commodity or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of another identical element in the commodity or device comprising said element.

[0033] In the related technologies of this field, the optoelectronic probes for detecting pulsed lasers mainly rely on the photoelectric effect. The photoelectric effect refers to the phenomenon that when photons in a laser beam irradiate the surface of a pulsed laser detection device with a specific energy, if the energy of the photons is greater than or equal to the work function of the material, the valence electrons in the material will absorb the energy of the photons and transition to the conduction band, becoming free electrons. These free electrons start to move under the action of an external electric field, forming an electric current, which is the direct manifestation of the photoelectric effect. In practical applications, by analyzing the current signal, researchers can accurately obtain the time characteristics of the laser pulse, including information such as pulse width, waveform, and repetition frequency. The pulsed laser detection devices using traditional detection technologies based on the photoelectric effect usually directly irradiate the incident laser on the diaphragm, resulting in a relatively low damage threshold of the pulsed laser detection device. It is prone to damage when detecting high-energy and high-power lasers. Moreover, the wavelength response range of a single probe is narrow, unable to meet the detection requirements of different wavelength laser sources. At the same time, the cost of such pulsed laser detection devices is relatively high, making it difficult to achieve large-scale applications.

[0034] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a pulsed laser detection device, including: a first housing, internally provided with a photoacoustic conversion module and a piezoelectric conversion module; a second housing, disposed inside the first housing, and the second housing is internally provided with the photoacoustic conversion module, including: an input aperture, disposed on the side wall of the second housing, configured to limit the diameter or spatial range of the incident laser entering the acoustic cavity; a diaphragm, disposed inside the second housing, and enclosing an acoustic cavity with the side wall of the second housing and the input aperture; a scattering cone, disposed inside the acoustic cavity, configured to block the direct irradiation of the incident laser on the diaphragm.

[0035] Based on the photoacoustic effect, the pulsed laser irradiates the scattering cone, and the scattering cone scatters the incident laser into a wide-angle distribution, causing the light beam to undergo multiple reflections in the acoustic cavity. During this process, the light energy is converted into heat energy, and the heat energy is transferred to the air, thereby generating a strong acoustic signal, realizing the conversion of heat energy into acoustic energy. This acoustic signal can reflect parameter information such as the pulse width and frequency of the laser pulse. The acoustic wave then drives the diaphragm to vibrate, and the capacitance between the diaphragm and the fixed electrode also changes with the sound, thereby generating an alternating voltage signal that changes with the acoustic wave, realizing the conversion of acoustic energy into electrical energy.

[0036] The optional embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0037] An embodiment of the present disclosure provides a pulsed laser detection device 1000, which mainly includes an input aperture 210, a first housing 100, a second housing 200, a sound cavity 201, a diaphragm 220, a scattering cone 230, an insulating gasket 240, a back plate 250, a transistor 260, a signal amplifier 300, and a refrigeration air pump 400. The first housing 100 is a sound-insulating cover that is transparent to a wide spectrum of light, configured to reduce the influence of external noise. The first housing 100 is internally provided with a photoacoustic conversion module and a photoacoustic-electric conversion module. The second housing 200 is disposed inside the first housing 100, and the second housing 200 is internally provided with the photoacoustic conversion module. The photoacoustic conversion module includes an input aperture 210, a diaphragm 220, and a scattering cone 230. The input aperture 210 and the diaphragm 220 form a sound cavity 201, and the scattering cone 230 is disposed in the sound cavity 201 and configured to block the incident laser from directly irradiating the diaphragm 220.

[0038] Based on the photoacoustic effect, when a pulsed laser irradiates the scattering cone 230, the scattering cone 230 scatters the incident laser into a wide-angle distribution, causing the light beam to undergo multiple reflections in the sound cavity 201. During this process, light energy is converted into heat energy, and the heat energy is transferred to the air, thereby generating a strong acoustic wave signal, realizing the conversion of heat energy into acoustic energy. This acoustic wave signal can reflect parameter information such as the pulse width and frequency of the laser pulse. The acoustic wave then drives the diaphragm 220 to vibrate, and the capacitance between the diaphragm 220 and the fixed electrode also changes with the sound, thereby generating an alternating voltage signal that changes with the acoustic wave, realizing the conversion of acoustic energy into electrical energy.

[0039] In some embodiments, the input aperture 210 is disposed on the side wall of the second housing 200 and configured to limit the diameter or spatial range of the incident laser entering the sound cavity 201. Specifically, the input aperture 210 can limit the diameter or spatial range of the laser beam entering the detection device, making the light beam more concentrated, reducing the influence of stray light, and improving the accuracy and precision of detection. In practical applications, by selecting an appropriate aperture size of the aperture, the light energy entering the device can be controlled, avoiding damage to the pulsed laser detection device 1000 due to excessive light energy or too weak a signal due to too low light energy, ensuring that the pulsed laser detection device 1000 operates within the optimal energy range, and improving the sensitivity and dynamic range of detection.

[0040] In some embodiments, the input aperture 210 can block the parts of the light beam with uneven intensity or poor quality, and only allow the central part of the light beam with better quality to pass through, thereby improving the quality of the light beam entering the detection device and enhancing the reliability and stability of the detection result.

[0041] In some embodiments, the diaphragm 220 is disposed inside the second housing 200. By receiving optical signals or thermal signals to adjust the vibration frequency and amplitude of the diaphragm 220, it is possible to generate a modulation signal with a specific frequency for the reflected or scattered laser, so as to calibrate the detection device, test, or study the characteristics of the interaction between the laser and the target, providing a reference and basis for actual target detection.

[0042] In some embodiments, the diaphragm 220 is a semi-permanent polarization dielectric formed by processing a polymer, such as plastic. It is essentially a pre-polarized dielectric. During the manufacturing process, the diaphragm 220 material is "permanently" charged under the action of a strong external electric field, forming a fixed electric field. This electric field enables the diaphragm 220 to still work properly without an external power supply.

[0043] In some embodiments, the diaphragm 220 can be a poled material with stable electrical properties, capable of maintaining charge for a long time to ensure the stable performance of the detection device. At the same time, since the charge of the poled diaphragm is fixed, its sensitivity is relatively high, capable of capturing weak acoustic signals. The diaphragm 220 also has good elasticity and temperature resistance, enabling the diaphragm 220 to effectively respond to acoustic changes and work in a variety of environments.

[0044] In some embodiments, the diaphragm 220, the side wall of the second housing 200, and the input aperture 210 enclose to form an acoustic cavity 201. A scattering cone 230 is disposed in the acoustic cavity 201, configured to block the incident laser from directly irradiating the diaphragm 220. A support frame is also disposed in the acoustic cavity 201. Specifically, the scattering cone 230 is positioned in front of the diaphragm 220 by the support frame, scattering the incident laser into a wide-angle distribution, blocking it from directly irradiating the surface of the diaphragm 220, and causing the light beam to undergo multiple reflections in the acoustic cavity 201, increasing the absorption efficiency of the inner wall of the acoustic cavity 201 and the gas for the laser energy, and keeping the scattering cone 230 stable in the acoustic cavity 201.

[0045] In some embodiments, the scattering cone 230 is a multi-pyramid, made of optical glass or quartz, and is used to scatter the incident laser according to the shape and angle of the scattering cone 230, thereby changing the propagation path of the light and making the incident laser evenly scattered in multiple directions.

[0046] In some embodiments, the scattering cone 230 is preferably a cone, made of optical glass or quartz, and is configured to scatter the incident laser into a wide-angle distribution so that the incident laser undergoes multiple reflections in the acoustic cavity 201.

[0047] In some embodiments, the scattering cone 230 is provided with an optical window at the cone tip or other parts. The optical window is a transparent component, usually made of optical materials with high transparency and low scattering, such as optical glass, quartz, etc., and is used to guide or reflect the scattered laser. Due to the use of materials with high transparency and low scattering, the optical window can minimize the additional scattering and absorption of the scattered light, ensure that the intensity and characteristics of the scattered light are not affected, and thus improve the accuracy of laser detection.

[0048] In some embodiments, the acoustic-electric conversion module includes a back plate 250, which is disposed on the side of the diaphragm 220 away from the scattering cone 230 and is configured to jointly form a capacitive structure with the diaphragm 220. Wherein, in response to the diaphragm 220 being vibrated by sound waves, the capacitance between the diaphragm 220 and the back plate 250 changes to achieve acoustic-electric conversion.

[0049] The back plate 250 is a fixed electrode, made of a metal material, such as aluminum, copper, etc. The back plate 250 is located behind the diaphragm 220, and the surface of the back plate 250 may be provided with through holes, configured to achieve pressure balance with the external environment. When the diaphragm 220 vibrates due to sound waves, the air pressure in front of the back plate 250 will change. The through holes allow air to flow, thereby reducing the influence of the pressure change in front of the back plate 250 on the performance of the sensor and ensuring the sensitivity and response speed of the diaphragm 220.

[0050] In some embodiments, the acoustic-electric conversion module further includes: an insulating gasket 240, which is disposed between the diaphragm 220 and the back plate 250 and is configured to separate the diaphragm 220 from the back plate 250 to form the capacitive structure.

[0051] The insulating gasket 240 separates the diaphragm 220 from the back plate 250, making the two present a capacitive structure. The output signal of this structure has a relatively high output impedance.

[0052] In some embodiments, the acoustic-electric conversion module further includes: a transistor 260 and a signal amplifier 300. The transistor 260 is disposed on the inner wall of the first housing 100 and can be used as an impedance matching stage to ensure that the signal can be effectively transmitted to the subsequent circuit, reducing signal loss and distortion. The signal amplifier 300 is disposed inside the second housing 200 and is connected to the transistor 260, configured to amplify the signal from the transistor 260.

[0053] In some embodiments, the acoustic cavity 201 is further connected to an external refrigeration air pump 400. The refrigeration air pump 400 can be a low-speed circulating refrigeration air pump 400, configured to dissipate heat and cool the interior of the acoustic cavity 201, and is applicable to application scenarios that require a relatively high detection power. Specifically, the refrigeration air pump 400 is disposed outside the first housing 100. Both ends of the refrigeration air pump 400 penetrate through the first housing 100 and the second housing 200 respectively to extend into the acoustic cavity 201, and is configured to dissipate heat from the acoustic cavity 201.

[0054] In some embodiments, the gas inside the refrigeration air pump 400 can be replaced according to the incident laser wavelength to enhance the photoacoustic conversion effect and improve the detection sensitivity. To prevent noise from affecting the detection result, a low-speed gas circulation mode is adopted. For example, when the incident laser is a 10 μm long wave, the gas inside the refrigeration air pump 400 can be replaced with CO2. This gas has a significant absorption band in the long wave band, which can improve the light absorption efficiency of the gas.

[0055] In some embodiments, the working process of the pulsed laser detection device 1000 provided by the present disclosure is as follows: The incident laser first passes through the apertures of the incident light apertures through the first housing 100 and the second housing 200, and then projects onto the surface of the scattering cone 230. The scattering cone 230 reflects the light at a wide angle to the inner wall of the second housing 200, and after multiple scatterings, the acoustic cavity 201 absorbs the light energy carried by the incident laser, and converts this energy into heat energy through the photo-thermal effect, thereby inducing a sharp fluctuation in the air temperature inside the acoustic cavity 201. This rapid change in temperature excites the generation of sound waves. During the propagation of the sound waves in the acoustic cavity 201, they interact with the diaphragm 220, causing the diaphragm 220 to generate periodic vibrations, changing the plate spacing of the capacitor structure formed between it and the back plate 250, and further affecting the capacitance value of this capacitor. This dynamic change in capacitance converts the sound wave signal into a measurable electrical signal. The initial impedance of the capacitor structure formed by the diaphragm 220 and the back plate 250 is too large and is not suitable for direct output, so impedance conversion needs to be performed via the transistor 260. Finally, the electrical signal is sent into the signal amplifier 300 for gain processing to enhance the intensity and signal-to-noise ratio of the signal.

[0056] The present disclosure also has other working modes. When detecting a laser with a relatively high power, the external low-speed circulating refrigeration air pump 400 can be turned on to dissipate heat from the acoustic cavity 201, greatly improving the power limit of the laser that can be detected. And when detecting pulsed lasers in certain bands, the gas inside the low-speed circulating refrigeration air pump 400 can be replaced, thereby improving the light absorption efficiency of the gas and further improving the photoacoustic efficiency.

[0057] Compared with traditional detection technologies based on the photoelectric effect, the innovative solution proposed in the present invention exhibits several remarkable advantages. Firstly, this technology has a higher tolerance in terms of damage threshold compared to the photoelectric probe technology, thus demonstrating stronger reliability under extreme environmental conditions. This characteristic enables the technology to have greater applicability in high-energy density application scenarios. Secondly, the design of the scattering cone 230 gives the pulsed laser detection device 1000 the advantage of a large dynamic range, improving the system adaptability and data quality. In addition, the physical structure of this technology is relatively simplified and has lower requirements for manufacturing precision, which significantly reduces its production cost compared to traditional photoelectric probes, thus providing economic feasibility for large-scale applications. At the same time, this technology covers most wavelength bands in the wavelength response range, further enhancing its applicability and flexibility. Finally, as a new detection technology, this solution shows great technical potential and is worthy of in-depth exploration and development. In summary, the innovative solution of the present invention not only demonstrates excellent performance in the field of pulsed laser detection, but also opens up new perspectives and paths for in-depth discussion and practical application in related research fields, indicating its broad application prospects and profound scientific value.

[0058] Compared with related technologies, the pulsed laser detection device 1000 provided in the embodiments of the present disclosure includes a photoacoustic conversion module and an electroacoustic conversion module, and the photoacoustic conversion module includes a scattering cone 230. The scattering cone 230 is disposed in the acoustic cavity 201 and can scatter the incident laser into a wide-angle distribution, blocking it from directly irradiating the surface of the diaphragm 220. This greatly improves the damage threshold of the detection device and promotes the beam to undergo multiple reflections in the acoustic cavity 201, increasing the absorption efficiency of the acoustic cavity 201 for laser energy. This design significantly reduces the detection threshold of the pulsed signal on the premise of ensuring the improvement of the damage threshold of the diaphragm 220, and improves the detection dynamic range. The pulsed laser detection device 1000 has the advantages of a high damage threshold, a wide wavelength response range, a large dynamic range, and a low cost.

[0059] For the specific structure, working principle, and beneficial effects of the pulsed laser detection device provided in the embodiments of the present disclosure, reference can be made to the pulsed laser detection device described in any of the above embodiments, and details will not be elaborated here.

[0060] Finally, it should be noted that the embodiments in this specification are described in a progressive manner, and the key point of each embodiment is to describe the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the systems or devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions in the method part.

[0061] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit it; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A pulsed laser detection device, characterized in that, Comprising: A first housing, inside which a photoacoustic conversion module and a piezoelectric conversion module are provided; A second housing, disposed inside the first housing, and inside the second housing, the photoacoustic conversion module is provided, including: An input diaphragm, disposed on the side wall of the second housing, configured to limit the diameter or spatial range of the incident laser entering the acoustic cavity; A diaphragm, disposed inside the second housing, and enclosing an acoustic cavity with the side wall of the second housing and the input diaphragm; A scattering cone, disposed inside the acoustic cavity, configured to block the incident laser from directly irradiating the diaphragm.

2. The pulsed laser detection device according to claim 1, wherein The scattering cone scatters the incident laser into a wide-angle distribution, configured to cause the incident laser to reflect multiple times inside the acoustic cavity.

3. The pulsed laser detection device according to claim 1, wherein The scattering cone is a cone or a multi-pyramid.

4. The pulsed laser detection device according to claim 1, wherein Further comprising: A support frame, disposed inside the acoustic cavity, configured to keep the scattering cone stable inside the acoustic cavity.

5. The pulsed laser detection device according to claim 1, wherein The scattering cone is made of optical glass or quartz.

6. The pulsed laser detection device according to claim 1, wherein The first housing is a sound-insulating cover with wide-spectrum light transmission, configured to reduce the influence of external noise.

7. The pulsed laser detection device according to claim 1, characterized in that The piezoelectric conversion module includes: A back plate, disposed on the side of the diaphragm away from the scattering cone, configured to jointly form a capacitive structure with the diaphragm, wherein, in response to the diaphragm being vibrated by sound waves, the capacitance between the diaphragm and the back plate changes to achieve piezoelectric conversion.

8. The pulsed laser detection device according to claim 7, wherein The piezoelectric conversion module further includes: An insulating gasket, disposed between the diaphragm and the back plate, configured to separate the diaphragm and the back plate to form the capacitive structure.

9. The pulsed laser detection device according to claim 6, characterized in that, The piezoelectric conversion module further includes: A transistor, disposed on the inner wall of the first housing; A signal amplifier, disposed inside the second housing, connected to the transistor, configured to amplify the electrical signal.

10. The pulsed laser detection device according to claim 6, characterized in that, Further comprising: A refrigeration air pump, disposed outside the first housing, and both ends of the refrigeration air pump respectively penetrate the first housing and the second housing to extend into the acoustic cavity, configured to dissipate heat from the acoustic cavity.

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