Pulse laser detection device

Abstract

The invention relates to the technical field of optical instruments, and particularly provides a pulse laser detection device, which comprises a first shell, a second shell and a laser detection device, the second shell is arranged in the first shell, the opto-acoustic conversion module is arranged in the second shell, and the second shell comprises an input diaphragm configured to limit the diameter or the space range of incident laser entering an acoustic cavity; the vibrating diaphragm is arranged in the second shell, and an acoustic cavity is defined by the vibrating diaphragm, the side wall of the second shell and the input diaphragm; and the scattering cone is arranged in the sound cavity and is configured to prevent the incident laser from directly irradiating the vibrating diaphragm. In the pulse laser detection device, the opto-acoustic conversion module comprises a scattering cone, the scattering cone can scatter incident laser to be distributed in a wide angle and prevent the incident laser from directly irradiating the surface of the vibrating diaphragm, so that the damage threshold of the detection device is greatly improved, light beams are promoted to be reflected for multiple times in the acoustic cavity, and the absorption efficiency of the acoustic cavity on laser energy is improved.

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 varies with time, periodic temperature fluctuations are generated, triggering mechanical vibrations in the surrounding medium, such as tissue or air, to form acoustic signals. This phenomenon is called the photoacoustic effect, which is the conversion result among 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, valence electrons in the material will 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 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. 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: 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 inside; a second housing disposed inside the first housing, and the photoacoustic conversion module is disposed inside the second housing, 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, 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.

[0005] In some embodiments, the scattering cone scatters the incident laser into a wide-angle distribution, configured to cause the incident laser to be reflected multiple times inside the acoustic cavity.

[0006] In some embodiments, the scattering cone is a cone or a polyhedron cone.

[0007] 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.

[0008] In some embodiments, the scattering cone is made of optical glass or quartz.

[0009] 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.

[0010] 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. 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.

[0011] 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 and the back plate to form the capacitive structure.

[0012] 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 an electrical signal.

[0013] In some embodiments, the pulsed laser detection device further includes: a refrigerating air pump disposed outside the first housing, and both ends of the refrigerating air pump respectively penetrate through the first housing and the second housing to extend into the acoustic cavity and are configured to dissipate heat from the acoustic cavity.

[0014] 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 disposed inside the acoustic cavity, which can scatter the incident laser into a wide-angle distribution and prevent 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. 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.

[0015] 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

[0016] 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, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings: Figure 1 Schematic structural diagram of a pulsed laser detection device shown according to an exemplary embodiment.

[0017] Reference numerals: First housing 100; Second housing 200, acoustic cavity 201, input diaphragm 210, diaphragm 220, scattering cone 230; Insulating gasket 240, back plate 250, transistor 260; Signal amplifier 300, refrigeration air pump 400; pulsed laser detection device 1000. Detailed implementation manners

[0018] 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.

[0019] 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 thereto.

[0020] It should be understood that although the terms first, second, third, etc. 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 may also be referred to as the second, and similarly, the second may also be referred to as the first. In addition, the terms "first", "second", "third", etc. are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] It should be understood that the term "and / or" used herein is merely a description of the associated relationship of associated objects, indicating that three relationships can exist. 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.

[0022] Furthermore, it can be further understood that the orientation or positional relationships indicated by terms such as "center", "longitudinal", "transverse", "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. It is 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 therefore should not be construed as a limitation of the present invention.

[0023] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "coupled" 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.

[0024] 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)".

[0025] 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.

[0026] In the related art of this field, currently, the optoelectronic probes for detecting pulsed lasers are mainly based 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 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. The pulsed laser detection devices used in traditional detection technologies based on the photoelectric effect usually directly irradiate the incident laser on the diaphragm, resulting in a low damage threshold of the pulsed laser detection device. It is prone to damage when detecting high-energy and high-power lasers, and 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.

[0027] 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.

[0028] 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 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 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.

[0029] The optional embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0030] 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 an electroacoustic 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 prevent the incident laser from directly irradiating the diaphragm 220.

[0031] 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.

[0032] 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 the 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 the detection.

[0033] 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 part with better quality in the central part 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.

[0034] In some embodiments, the diaphragm 220 is disposed inside the second housing 200. By receiving an optical signal or a thermal signal 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, and provide a reference and basis for actual target detection.

[0035] 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 material of the diaphragm 220 is "permanently" charged under the action of a strong external electric field to form a fixed electric field. This electric field enables the diaphragm 220 to still work properly without an external power supply.

[0036] In some embodiments, the diaphragm 220 can be a poled material with stable electrical properties, capable of holding charges for a long time to ensure the stable performance of the detection device. At the same time, since the charges of the poled diaphragm are 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 changes in sound waves and work in a variety of environments.

[0037] 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 and 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, scatters the incident laser into a wide-angle distribution, blocks it from directly irradiating the surface of the diaphragm 220, and causes 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.

[0038] 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 uniformly scattered in multiple directions.

[0039] 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.

[0040] 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.

[0041] In some embodiments, the acoustic-electric conversion module includes a back plate 250. The back plate 250 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.

[0042] The back plate 250 is a fixed electrode, made of a metal material, such as aluminum, copper. The back plate 250 is located behind the diaphragm 220. Open holes may be provided through the surface of the back plate 250 and are 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 open 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.

[0043] In some embodiments, the acoustic-electric conversion module further includes: an insulating gasket 240, disposed between the diaphragm 220 and the back plate 250 and configured to separate the diaphragm 220 from the back plate 250 to form the capacitive structure.

[0044] 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.

[0045] 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 and reduce signal loss and distortion. The signal amplifier 300 is disposed inside the second housing 200 and is connected to the transistor 260 and is configured to amplify the signal from the transistor 260.

[0046] 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 refrigerate 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.

[0047] In some embodiments, the gas inside the refrigeration air pump 400 can be replaced according to the wavelength of the incident laser 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 laser, the gas inside the refrigeration air pump 400 can be replaced with CO 2 , which has a significant absorption band in the long-wave band and can improve the light absorption efficiency of the gas.

[0048] 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 first housing 100 and the second housing 200 and passes through the aperture of the incident aperture, and then is projected 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 photothermal 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 capacitance 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 capacitance 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.

[0049] 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 detectable laser. 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.

[0050] 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 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 endows the pulsed laser detection device 1000 with the advantage of a large dynamic range, enhancing the system adaptability and data quality. In addition, the physical structure of this technology is relatively simplified, and the requirement for manufacturing precision is relatively low, which significantly reduces its production cost compared to traditional photoelectric probes, thereby providing economic feasibility for large-scale applications. Meanwhile, 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 demonstrates great technical potential and is worthy of in-depth exploration and development. In summary, the innovative solution of the present invention not only exhibits excellent performance in the field of pulsed laser detection, but also opens up new perspectives and paths for in-depth exploration and practical applications in related research fields, indicating its broad application prospects and profound scientific value.

[0051] 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.

[0052] 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 are not elaborated here.

[0053] Finally, it should be noted that the embodiments in this specification are described in a progressive manner, with each embodiment focusing on 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.

[0054] 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 pulse laser detection device, characterized in that: include: A first housing, in which a photoacoustic conversion module and an acoustic-electric conversion module are arranged; The second shell is arranged inside the first shell, and the photoacoustic conversion module is arranged inside the second shell, including: An input aperture, disposed on the side wall of the second housing, configured to limit the diameter or spatial range of incident laser light entering the acoustic cavity; A diaphragm is disposed inside the second housing and is surrounded by a side wall of the second housing and the input aperture to form a sound cavity; A scattering cone is disposed in the acoustic cavity and is configured to block the incident laser from directly irradiating the diaphragm.

2. The pulse laser detection device according to claim 1, characterized in that: The scattering cone scatters the incident laser light into a wide-angle distribution and is configured to cause the incident laser light to be reflected multiple times in the acoustic cavity.

3. The pulse laser detection device according to claim 1, characterized in that: The scattering cone is a circular cone or a polygonal cone.

4. The pulse laser detection device according to claim 1, characterized in that: Also includes: A support frame is disposed inside the acoustic cavity and is configured to keep the scattering cone stable in the acoustic cavity.

5. The pulse laser detection device according to claim 1, characterized in that: The scattering cone is made of optical glass or quartz.

6. The pulse laser detection device according to claim 1, characterized in that: The first shell is a soundproof enclosure with wide spectrum transmittance, configured to reduce the impact of external noise.

7. The pulse laser detection device according to claim 1, characterized in that: The sound-to-electric conversion module comprises: A back plate is disposed on a side of the diaphragm away from the scattering cone and is configured to form a capacitive structure together with the diaphragm. 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.

8. The pulse laser detection device according to claim 7, characterized in that: The sound-to-electric conversion module also includes: An insulating liner is disposed between the diaphragm and the back plate, and is configured to separate the diaphragm from the back plate to form the capacitive structure.

9. The pulse laser detection device according to claim 6, characterized in that: The sound-to-electric conversion module also includes: A transistor, arranged on the inner wall of the first shell; The signal amplifier is disposed inside the second shell, connected to the transistor, and configured to amplify the electrical signal.

10. The pulse laser detection device according to claim 6, characterized in that: Also includes: A refrigeration air pump is arranged outside the first shell, and two ends of the refrigeration air pump respectively penetrate the first shell and the second shell to extend into the acoustic cavity, and is configured to dissipate heat for the acoustic cavity.

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