Fluorescent conversion sheet with wavelength up-conversion function and handheld smoke penetration imaging device

Abstract

The application relates to the fields of optics and fire rescue, and discloses a fluorescent conversion sheet with wavelength conversion function and a handheld smoke penetration imaging device. The fluorescent conversion sheet comprises, in sequence, a heat dissipation substrate layer, a mirror layer, a photonic crystal layer and a core-shell structure fluorescent layer. After short-wave near-infrared laser is incident, the core-shell structure fluorescent layer performs wavelength conversion; the mirror layer and the photonic crystal layer form an optical micro resonant cavity, and the unconverted laser is reflected back to the fluorescent layer for secondary conversion; and the heat dissipation substrate layer effectively suppresses the thermal quenching effect. The imaging device utilizes the fluorescent conversion sheet to efficiently convert the easily obtained short-wave near-infrared laser into middle-wave near-infrared laser with strong smoke penetration capability and safety to human eyes and emits the middle-wave near-infrared laser, and a receiving device containing a polarizer is used to image the target echo. Through systematic and synergistic optimization design, the conversion efficiency and thermal stability are greatly improved, excellent smoke penetration imaging effect is realized, and the safety and efficiency of fire rescue are improved.

Description

Technical Field

[0001] This invention relates to the fields of optics and fire rescue, and particularly to a fluorescence converter with wavelength upconversion function and a handheld smoke penetration imaging device. Background Technology

[0002] Smoke is one of the most deadly factors threatening the lives of firefighters in a fire. Dense smoke not only contains large amounts of highly toxic gases such as carbon monoxide and hydrogen cyanide, which can cause unconsciousness and death within 3-5 minutes, but its opaque nature also forces firefighters into a desperate situation of "walking blindly with their eyes open." In the black smoke wall where visibility is less than 1 meter, rescuers not only have to contend with the high temperatures that burn their respiratory tract (smoke temperatures in fire scenes often reach over 300°C), but also face the deadly risks of disorientation and oxygen depletion.

[0003] Currently, single-photon lidar, laser range-gated imaging, infrared thermal imaging, and penetration imagers are some of the main imaging technologies for penetrating smoke. Each technology has its unique advantages and application scenarios, but also certain limitations. For example, infrared thermal imaging is limited in high-temperature smoke environments, while single-photon lidar and laser range-gated imaging, although excellent in penetrating smoke, are costly and technically complex. CN221326759U discloses a laser-based fire and smoke penetration reconnaissance and search and rescue equipment that uses laser range-gated technology, but this method is limited by the near-infrared image intensifier, resulting in poor smoke penetration. Furthermore, this technology relies on a signal synchronization control unit to control laser range gating, which is costly and cannot image targets within the imaging range in a single pass, requiring manual adjustment of the imaging distance. Finally, high-power near-infrared lasers pose a risk of eye damage.

[0004] Based on the principle of smoke particle scattering, the core factor determining smoke penetration capability is wavelength. Mid-wave near-infrared lasers offer significant advantages. First, mid-wave near-infrared laser wavelengths fall within the eye-safe band, with a much higher safe exposure level than other commonly used wavelengths. This means that higher luminous power can be achieved while ensuring eye safety, resulting in longer detection distances. Second, mid-wave near-infrared lasers have better penetration capability for particulate matter in smoke within the atmospheric transmission window, approximately 10 times that of short-wave near-infrared wavelengths. Furthermore, mid-wave near-infrared laser wavelengths fall within the detection sensitivity range of room-temperature Ge and InGaAs detectors, and mature PIN and APD components are available, greatly facilitating the detection of mid-wave near-infrared lasers. These advantages make mid-wave near-infrared lasers perform exceptionally well in smoke-penetrating imaging technology, effectively improving image quality and detection distance.

[0005] Traditional fluorescence conversion sheets mostly use a single-pass transmission method for wavelength conversion, which wastes a large amount of unconverted short-wave near-infrared laser light, resulting in low conversion efficiency. Furthermore, during the conversion process, non-radiative transitions generate thermal images, leading to thermal quenching effects, which severely affect the fluorescence conversion efficiency. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in related technologies. To this end, the present invention provides a fluorescence conversion sheet with wavelength upconversion function and a handheld smoke penetration imaging device.

[0007] The first option is:

[0008] A fluorescent converter with wavelength upconversion function,

[0009] The system includes a multi-layered heterogeneous structure for converting short-wave near-infrared laser light into mid-wave near-infrared laser light. The multi-layered heterogeneous structure sequentially comprises a heat-dissipating substrate layer, a reflective mirror layer, a photonic crystal layer, a core-shell fluorescent layer, and a protective layer, wherein:

[0010] The heat dissipation base layer is made of a high thermal conductivity material to dissipate the heat generated during the conversion process and suppress the thermal quenching effect.

[0011] The reflector layer is used to reflect unconverted short-wave near-infrared laser light, realizing a two-way conversion path;

[0012] The photonic crystal layer has a periodic dielectric structure, forming a photonic bandgap for short-wavelength near-infrared lasers, which is used to modulate the photonic density of states and reduce light absorption loss.

[0013] The core-shell structure fluorescent layer is doped with sensitizers and activators to absorb short-wave near-infrared lasers and emit mid-wave near-infrared lasers.

[0014] The protective layer is a transparent medium used to protect the core-shell fluorescent layer and improve the light extraction efficiency;

[0015] The fluorescent conversion sheet achieves efficient conversion from short-wave near-infrared laser to mid-wave near-infrared laser through the synergistic effect of the multilayer heterogeneous structure.

[0016] Furthermore, the heat dissipation substrate is composed of sapphire, aluminum nitride, or high-purity copper.

[0017] Furthermore, the photonic crystal layer adopts a nanoscale periodic dielectric constant structure, and the wavelength range of the photonic bandgap covers the short-wave near-infrared laser band.

[0018] Furthermore, the core-shell fluorescent layer includes nanoscale luminescent particles, which are doped with a high concentration of Yb³⁺ as a sensitizer and Er³⁺ as an activator, and employ a core-shell structure to suppress surface quenching.

[0019] Furthermore, the reflector layer and the photonic crystal layer together form an optical micro-resonant cavity, which is used to lock the space of short-wave near-infrared laser photons within the core-shell fluorescent layer to achieve high energy concentration.

[0020] Based on the first technical solution, a second technical solution was proposed.

[0021] A handheld smoke penetration imaging device includes a housing, a handle, a base, a power module, a control module, a detection device, a receiving device, and a display module, wherein:

[0022] The handle is located at the lower part of the outer shell, the base is located at the bottom of the handle, and the power module is installed inside the handle;

[0023] The control module includes a main control board and a keypad, used to control the laser emission of the detection device and the image acquisition of the receiving device;

[0024] The detection device includes a short-wave near-infrared laser, a laser driver board, a multilayer heterogeneous fluorescence converter, a focusing mask, and a polarizer. The laser generated by the short-wave near-infrared laser is converted into a mid-wave near-infrared laser by the multilayer heterogeneous fluorescence converter. The mid-wave near-infrared laser is focused by the focusing mask and polarized by the polarizer before being emitted from the laser emission window.

[0025] The receiving device includes an imaging lens, an analyzer, and an image acquisition and processing module, used to receive mid-wave near-infrared laser light reflected from the target, perform imaging, and process image information.

[0026] The display module is a screen used to display the processed image information;

[0027] The device achieves mid-wave near-infrared laser generation and smoke penetration imaging through the multilayer heterogeneous fluorescence conversion sheet, wherein the multilayer heterogeneous fluorescence conversion sheet is the fluorescence conversion sheet described in the first technical solution.

[0028] Furthermore, the detection device also includes a filter, which is disposed on the polarizer to filter out clutter and make the mid-wave near-infrared laser purer.

[0029] Furthermore, the image acquisition and processing module is a mid-wave near-infrared laser-sensitive detector or a gated selection camera, supporting image storage, export, video recording, and photo taking functions.

[0030] Furthermore, the device also includes a heat dissipation device, which is a heat sink and / or a cooling fan, installed on both sides of the detection device and the receiving device.

[0031] Furthermore, the multilayer heterogeneous fluorescent converter is integrated with the polarizer to directly generate mid-wave near-infrared laser with polarization characteristics.

[0032] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0033] Improved conversion efficiency: A mirror layer is used to realize a two-way conversion path, a photonic crystal layer regulates the photon density of states, and a core-shell fluorescent layer suppresses surface quenching. The overall synergy optimizes the conversion efficiency of short-wave near-infrared laser to mid-wave near-infrared laser and reduces energy waste.

[0034] Suppressing thermal quenching effect: The heat dissipation substrate layer uses high thermal conductivity materials (such as sapphire or aluminum nitride) to quickly dissipate waste heat, allowing high-power pump operation and ensuring the stability and long life of the phosphor conversion sheet in high-temperature environments.

[0035] Enhanced smoke penetration capability: Mid-wave near-infrared lasers have approximately 10 times the penetration power of short-wave near-infrared lasers within the atmospheric transmission window. Combined with polarization technology and an analyzer, it suppresses scattering interference, improves imaging quality and detection range, and is suitable for dense smoke scenarios such as fire rescue.

[0036] Eye safety and high power compatibility: Mid-wave and near-infrared lasers are eye-safe and can be operated at higher power without increasing the risk of eye damage. They can also be easily integrated using mature detectors.

[0037] Portability and practicality: The handheld device features a compact design that integrates a control module, heat dissipation device, and image processing functions. It supports real-time display, storage, and recording, improving firefighters' sense of direction and rescue efficiency in fire scenes. It is compatible with direct mid-wave near-infrared laser alternatives, providing a way to improve traditional short-wave near-infrared devices and reducing overall cost and technical complexity.

[0038] System stability and multifunctionality: The control module synchronizes laser emission and image acquisition to avoid multiple reflection interference; the protective layer improves light output efficiency and ensures the reliable performance of the device in harsh environments.

[0039] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the handheld smoke penetration imaging device of the present invention;

[0042] Figure 2 This is a side view of the structure of the handheld smoke penetration imaging device of the present invention;

[0043] Figure 3 This is a schematic diagram of the internal structure of the handheld smoke penetration imaging device of the present invention;

[0044] Figure 4 This is a structural diagram of the multilayer heterogeneous fluorescent conversion sheet of the present invention;

[0045] Figure 5 This is a diagram showing the optical path relationship of the handheld smoke penetration imaging device of the present invention for detecting target objects;

[0046] Figure 6 This is a diagram showing the signal acquisition and control relationship of the components of the handheld smoke penetration imaging device of the present invention.

[0047] Figure label:

[0048] 1. Base; 2. Handle; 3. Control buttons; 4. Housing; 5. Screen; 6. Switch; 7. Image receiving window; 8. Laser emitting window; 9. Battery; 10. Button board; 11. Main control board;

[0049] 12. Laser; 13. Laser driver board; 14. Multilayer heterogeneous phosphor converter; 15. Condenser; 16. Polarizer; 17. Filter; 18. Imaging lens; 19. Analyzer; 20. Camera;

[0050] 31. Heat dissipation substrate layer; 32. Mirror layer; 33. Photonic crystal layer; 34. Core-shell fluorescent layer; 35. Protective layer. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but should not be used to limit the scope of this invention.

[0052] The following is combined Figures 1 to 6 The detailed solution of the present invention is described below.

[0053] Figures 1 to 3 The structure and components of a handheld smoke penetration imaging device are shown.

[0054] Figure 4 The specific structure of a fluorescent converter sheet with wavelength upconversion function is shown.

[0055] Figure 5 and Figure 6 The connection relationships and detection control relationships of the components of the handheld smoke penetration imaging device are shown.

[0056] A handheld smoke penetration imaging device with a fluorescence conversion sheet featuring wavelength upconversion function.

[0057] The main structure of the handheld smoke penetration imaging device includes a housing 4, a handle 2, and a base 1;

[0058] The handle 2 is used for handheld operation during the detection process. The handle 2 is located at the lower part of the housing 4, and a base 1 is provided at the bottom of the handle 2.

[0059] The handle 2 has a power module inside, which uses battery 9 to provide power to the entire imaging device. The handle 2 also has a switch 6 connected to the power module to control the imaging device to turn on and off.

[0060] A screen 5 and control buttons 3 are provided on one side of the outer casing 4, with the screen 5 located above the control buttons 3;

[0061] On the other side, there is an image receiving window 7 and a laser emitting window 8; the image receiving window 7 is located below the laser emitting window 8.

[0062] Screen 5 is connected to main control board 11, and control buttons 3 are connected to button board 10. Main control board 11 and button board 10 are located inside housing 4. Button board 10 and main control board 11 are connected to form a control module.

[0063] The outer casing 4 houses a detection device and a receiving device. The detection device emits a detection laser through a laser emission window 8, while the receiving device receives the detection laser reflected from the target through an image receiving window 7. Heat dissipation devices, consisting of heat sinks and / or cooling fans, are installed on both sides of the detection and receiving devices.

[0064] The detection device includes a laser 12, a laser driver board 13, a multilayer heterogeneous phosphor converter 14, a condenser 15, and a polarizer 16.

[0065] Laser 12 is a short-wavelength near-infrared laser source, which includes a semiconductor light-emitting chip and a driving circuit.

[0066] The laser emitted by the short-wave near-infrared laser source is converted into a mid-wave near-infrared laser by a fluorescence conversion sheet.

[0067] The mid-wave near-infrared laser generated by the fluorescent conversion sheet is focused by the condenser 15 and then passes through the polarizer 16;

[0068] Polarizer 16 polarizes the mid-wave near-infrared laser;

[0069] A filter 17 can also be installed on the polarizer 16; the filter 17 filters out noise, making the mid-wave near-infrared laser purer.

[0070] The receiving device includes an imaging lens 18, an analyzer 19, and an image acquisition and processing module;

[0071] Mid-wave near-infrared laser is transmitted to the target through spatial smoke and then imaged by the imaging lens 18.

[0072] The polarizer 19 is used to detect optical signals with polarization characteristics;

[0073] The image acquisition and processing module acquires and processes the image information, which is then passed through the control module and displayed by the display module.

[0074] The display module is screen 5; the image acquisition and processing module is camera 20. The image acquisition and processing module acquires and processes target image information and has the functions of image storage, export, video recording and photo taking.

[0075] The image acquisition and processing module can use a detector sensitive to the mid-wave and near-infrared laser bands or a gated selection camera 20, or it can use a near-infrared detector plus fluorescence upconversion for detection.

[0076] The control module is used to control the laser emission of the detection device and the image acquisition and processing module to acquire image information.

[0077] The fluorescence conversion sheet is a multilayer heterogeneous fluorescence conversion sheet 14, which can achieve efficient conversion from short-wave near-infrared band to mid-wave near-infrared band.

[0078] The laser emitted by the short-wave near-infrared laser source is converted to a wavelength similar to that of a mid-wave near-infrared laser by the fluorescent conversion sheet.

[0079] The multilayer heterogeneous fluorescence converter 14 adopts a five-layer vertically integrated structure, consisting of a heat dissipation substrate layer 31, a mirror layer 32, a photonic crystal layer 33, a core-shell structure fluorescence layer 34, and a protective layer 35.

[0080] The heat dissipation substrate layer 31 effectively reduces the thermal quenching problem of high-power lasers, thereby improving conversion efficiency, because the temperature of the fluorescent material increases due to laser quantum loss, which alters the energy transfer path within the fluorescent material. The reflector layer 32 reflects the remaining unconverted near-infrared laser light after it passes through the fluorescent converter, allowing it to re-enter the photonic crystal layer 33 and the core-shell fluorescent layer 34. The protective layer 35 protects the photonic crystal layer 33 and the core-shell fluorescent layer 34.

[0081] The photonic crystal layer 33 is doped with a high concentration of erbium ions (Er³⁺) and combined with a co-doping strategy of alkaline earth metal ions (such as Mg²⁺, Ca²⁺, etc.). This can effectively control the matrix lattice field environment, enhance the absorption and radiation transition probability of Er³ ions in the near-infrared band, and suppress the concentration quenching effect. Combined with the mirror layer (32), a spectrally tunable resonant microcavity is constructed. Through the reflection-re-excitation mechanism, the emission-reflection two-way conversion is realized. That is, the photons emitted forward for the first time and the back photons returned by the mirror are reused to excite Er³⁺ ions again and induce secondary photon emission, thereby significantly improving the conversion efficiency and output intensity of short-wave near-infrared laser to mid-wave near-infrared laser and reducing heat loss.

[0082] The heat dissipation substrate 31 is located at the bottom of the entire structure and is made of a material with high thermal conductivity, such as sapphire (Al2O3), aluminum nitride (AlN), or high-purity copper (Cu).

[0083] The reflector layer 32 is a specially designed optical thin film, typically a distributed Bragg mirror (DBR) or a metallic reflective film. Its characteristics include extremely high reflectivity for pump light (SW-NIR) and high transmittance for the converted MW-NIR light.

[0084] Photonic crystal layer 33 is a material with a nanoscale periodic dielectric constant structure. By precisely designing its period and refractive index distribution, it forms a photonic bandgap (PBG) whose wavelength range precisely covers the SW-NIR pump light band.

[0085] The core-shell fluorescent layer 34 is the core functional layer for photon conversion. It consists of a large number of nanoscale luminescent particles dispersed in the matrix. These nanoparticles are doped with high concentrations of sensitizers (such as Yb³⁺) and activators (such as Er³⁺) and adopt a core-shell structure.

[0086] The protective layer 35 is a transparent dielectric layer located at the very top of the entire device. The material must be transparent to the emitted MW-NIR light and may be coated with an anti-reflection film to increase the light emission efficiency.

[0087] The advanced nature of this fluorescence conversion sheet does not stem from a single technology, but rather from the precise synergy of multiple physical mechanisms that construct a systematic solution for improving efficiency.

[0088] Photon management synergy: The mirror layer and the photonic crystal layer together form a highly efficient optical micro-resonator tailored to the pump light wavelength. They "lock" the SW-NIR pump photons within the narrow space of the fluorescent layer, achieving a high degree of energy concentration in the spatial dimension and greatly improving pump efficiency.

[0089] Synergistic energy conversion: Inside the fluorescent layer, the combination of Yb³⁺ sensitizer and Er³⁺ activator enables highly efficient interatomic energy transfer. Meanwhile, the core-shell microstructure fundamentally suppresses the primary energy loss pathway—surface quenching—and enhances the luminescence quantum efficiency at the microscale.

[0090] Synergistic thermal management: The waste heat that inevitably arises when the fluorescent layer is working at high efficiency is quickly conducted away by the adjacent heat dissipation substrate layer, thereby effectively suppressing the occurrence of thermal quenching effect on a macroscopic scale.

[0091] In summary, this is a design that comprehensively optimizes three dimensions: "photon path management," "microscopic energy conversion," and "macroscopic heat conduction." Logically, this design is complete and advanced, and theoretically, it can systematically solve the two core pain points of traditional upconversion materials under high-power pumping: low efficiency and poor thermal stability.

[0092] An alternative solution can be adopted for the mid-wave near-infrared laser generator used for detection. The combination of short-wave near-infrared laser and fluorescence conversion sheet can be directly replaced by a mid-wave near-infrared laser generator.

[0093] The fluorescence converter and polarizer can be combined to directly generate mid-wave near-infrared laser with polarization characteristics from the fluorescence converter.

[0094] The purpose of this invention in using a combination of short-wave near-infrared laser and a fluorescence converter is that short-wave near-infrared laser generators are readily available, and the combination with the fluorescence converter can efficiently convert them into mid-wave near-infrared lasers to achieve better fire detection, greatly improving the efficiency and accuracy of fire rescue.

[0095] The paper also presents an improvement method for a conventional short-wave near-infrared laser smoke penetration imaging device, which can be improved by adding a multi-layer heterogeneous fluorescence conversion sheet to enhance detection efficiency.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluorescent converter with wavelength up-conversion function, characterized in that, The system includes a multi-layered heterogeneous structure for converting short-wave near-infrared laser light into mid-wave near-infrared laser light. The multi-layered heterogeneous structure sequentially comprises a heat-dissipating substrate layer, a reflective mirror layer, a photonic crystal layer, a core-shell fluorescent layer, and a protective layer, wherein: The heat dissipation base layer is made of a high thermal conductivity material to dissipate the heat generated during the conversion process and suppress the thermal quenching effect. The reflector layer is used to reflect unconverted short-wave near-infrared laser light, realizing a two-way conversion path; The photonic crystal layer has a periodic dielectric structure, forming a photonic bandgap for short-wavelength near-infrared lasers, which is used to modulate the photonic density of states and reduce light absorption loss. The core-shell structure fluorescent layer is doped with sensitizers and activators to absorb short-wave near-infrared lasers and emit mid-wave near-infrared lasers. The protective layer is a transparent medium used to protect the core-shell fluorescent layer and improve the light extraction efficiency; The fluorescent conversion sheet achieves efficient conversion from short-wave near-infrared laser to mid-wave near-infrared laser through the synergistic effect of the multilayer heterogeneous structure.

2. The fluorescence converter with wavelength up-conversion function according to claim 1, characterized in that, The heat dissipation substrate is made of sapphire, aluminum nitride, or high-purity copper.

3. The fluorescence converter with wavelength up-conversion function according to claim 1, characterized in that, The photonic crystal layer adopts a nanoscale periodic dielectric constant structure, and the wavelength range of the photonic bandgap covers the short-wave near-infrared laser band.

4. The fluorescence converter with wavelength up-conversion function according to claim 1, characterized in that, The core-shell fluorescent layer comprises nanoscale luminescent particles, which are doped with a high concentration of Yb³⁺ as a sensitizer and Er³⁺ as an activator, and employ a core-shell structure to suppress surface quenching.

5. The fluorescence converter with wavelength up-conversion function according to claim 1, characterized in that, The reflector layer and the photonic crystal layer together form an optical micro-resonant cavity, which is used to lock short-wave near-infrared laser photons within the core-shell fluorescent layer to achieve high energy concentration.

6. A handheld smoke penetration imaging device, characterized in that, It includes a housing, handle, base, power module, control module, detection device, receiving device, and display module, wherein: The handle is located at the lower part of the outer shell, the base is located at the bottom of the handle, and the power module is installed inside the handle; The control module includes a main control board and a keypad, used to control the laser emission of the detection device and the image acquisition of the receiving device; The detection device includes a short-wave near-infrared laser, a laser driver board, a multilayer heterogeneous fluorescence converter, a focusing mask, and a polarizer. The laser generated by the short-wave near-infrared laser is converted into a mid-wave near-infrared laser by the multilayer heterogeneous fluorescence converter. The mid-wave near-infrared laser is focused by the focusing mask and polarized by the polarizer before being emitted from the laser emission window. The receiving device includes an imaging lens, an analyzer, and an image acquisition and processing module, used to receive mid-wave near-infrared laser light reflected from the target, perform imaging, and process image information. The display module is a screen used to display the processed image information; The device achieves mid-wave near-infrared laser generation and smoke penetration imaging through the multilayer heterogeneous fluorescence conversion sheet, wherein the multilayer heterogeneous fluorescence conversion sheet is the fluorescence conversion sheet as described in claim 1.

7. The handheld smoke penetration imaging device according to claim 6, characterized in that, The detection device also includes a filter, which is disposed on the polarizer to filter out noise and make the mid-wave near-infrared laser cleaner.

8. The handheld smoke penetration imaging device according to claim 6, characterized in that, The image acquisition and processing module is a mid-wave near-infrared laser-sensitive detector or a gated selection camera, supporting image storage, export, video recording, and photo taking functions.

9. The handheld smoke penetration imaging device according to claim 6, characterized in that, The device also includes a heat dissipation device, which is a heat sink and / or a cooling fan, installed on both sides of the detection device and the receiving device.

10. The handheld smoke penetration imaging device according to claim 6, characterized in that, The multilayer heterogeneous fluorescent converter is integrated with the polarizer to directly generate mid-wave near-infrared laser with polarization characteristics.

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