Liquid crystal polymer optical element protection fixture

Abstract

This invention discloses a protective fixing device for liquid crystal polymer optical elements, relating to the field of optical element fixing and heat dissipation technology. It includes a lens barrel and a fixing frame. The lens barrel forms a cavity, with a laser channel, a mounting port for inserting the optical element, and an air inlet and outlet for connecting to an external air source. The fixing frame is disposed within the cavity through the mounting port to fix the liquid crystal polymer optical element. The fixing frame divides the cavity on one side where the air inlet and outlet are located, forming isolated air inlet and outlet sections on opposite sides of the fixing frame. A gap is provided between the fixing frame and the inner wall of the cavity to allow gas to flow around the fixing frame. This invention, through the coordinated structural design of the lens barrel and the fixing frame, forces cooling gas to flow across the surface of the optical element, avoiding airflow short-circuiting and achieving efficient active air cooling, significantly improving the damage threshold of the liquid crystal polymer optical element under high-power laser irradiation.

Description

Technical Field

[0001] This invention relates to the field of optical element fixing and heat dissipation technology, and in particular to a protective fixing device for liquid crystal polymer optical elements. Background Technology

[0002] Liquid crystal polymer homogenizing optical elements are novel planar optical elements based on the principle of diffraction optics. The core consists of a sandwich structure formed by a liquid crystal polymer film and two windows, enabling efficient homogenization of Gaussian incident light and the generation of various flat-top beams. With its advantages of high diffraction efficiency, high uniformity, flexible parameters, and easy integration, this element has been widely adapted to different wavelength laser applications, becoming a core component for beam homogenization in industries such as photovoltaics, 3D printing, laser aesthetic medicine, and laser processing.

[0003] However, liquid crystal polymer homogenizing optical components face severe technical challenges in high-power laser environments. First, as organic materials, liquid crystal polymers are far less resistant to laser damage than inorganic optical materials. Research indicates that damage to liquid crystal materials under near-infrared high-power laser irradiation primarily stems from the decomposition of the liquid crystal material and alignment layer under laser-induced high-temperature conditions. The significant nonlinearity of liquid crystal materials makes macroscopic laser damage complex, potentially involving not only linear absorption processes but also nonlinear processes such as liquid crystal molecule reorientation, thermal density changes, and thermo-optic effects. Second, high-power infrared lasers cause rapid temperature increases in components. Prolonged exposure to high temperatures can lead to thermal degradation, deformation, and even damage to the liquid crystal polymer film, resulting in decreased homogenization performance, a problem particularly pronounced in continuous wave and high-repetition-frequency pulsed laser environments. Furthermore, damage to the component can cause uncontrolled laser scattering, which can not only damage equipment and disrupt the laboratory environment but also pose safety hazards.

[0004] To address the aforementioned issues, existing technologies have explored methods to reduce heat deposition on liquid crystal optical devices, such as optimizing device structure, improving heat dissipation systems, and adding auxiliary heat dissipation systems. For example, some studies have proposed using silicon-based substrates with higher thermal conductivity instead of quartz substrates to increase heat dissipation, while others have explored liquid crystal optical devices with air-cooling and water-cooling auxiliary heat dissipation systems. Furthermore, there are air-cooling devices for transmissive optical elements that achieve heat dissipation through symmetrical flow channel heat dissipation units.

[0005] However, existing technologies lack dedicated fixing and protection structures for liquid crystal polymer homogenized optical elements. Specifically, while existing air-cooling devices can achieve a certain degree of heat dissipation, they do not integrate the fixing, optical path sealing, and efficient heat dissipation of liquid crystal polymer optical elements into a single structural design. Existing devices struggle to reliably fix the optical elements while effectively guiding cooling gas across the surface of the optical elements to remove heat, resulting in insufficient heat dissipation efficiency. Consequently, the damage threshold of liquid crystal polymer optical elements under high-power laser irradiation remains low, failing to meet the demands of end-user industries upgrading to high power and high precision.

[0006] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] The purpose of this invention is to provide a protective fixing device for liquid crystal polymer optical elements to solve the problems existing in the prior art. It forces cooling gas to flow through the surface of the optical element to achieve efficient active air cooling and heat dissipation, thereby significantly improving the damage threshold of liquid crystal polymer optical elements under high-power laser irradiation and meeting the usage requirements of high-power laser application scenarios.

[0008] To achieve the above objectives, the present invention provides the following solution: A protective fixing device for liquid crystal polymer optical elements, comprising: The mirror tube has a cavity, and the mirror tube has a laser channel for laser to pass through, an installation port for optical elements to be installed, and an air inlet and an air outlet for gas to enter and exit. The air inlet and the air outlet are used to connect to an external gas source. A mounting bracket is disposed within the cavity of the lens barrel through the mounting port. The mounting bracket is used to fix the liquid crystal polymer optical element. The mounting bracket separates the cavity on the side where the air inlet and the air outlet are located, so that the air inlet and the air outlet are located on opposite sides of the mounting bracket, forming mutually isolated air inlet and air outlet sections. A gap is provided between the mounting bracket and the inner wall of the cavity to allow gas to flow around the mounting bracket.

[0009] In an exemplary embodiment, the cavity of the lens barrel is a cylindrical cavity, and the laser channel includes two light-transmitting holes respectively opened at the front end and the rear end of the lens barrel, and the two light-transmitting holes are coaxially arranged to allow the laser to pass through along the axial direction.

[0010] In one exemplary embodiment, both of the light-transmitting holes are provided with transparent partitions that allow laser light to pass through, which are used to seal the cavity to prevent gas leakage.

[0011] In an exemplary embodiment, the mounting port is opened on the side wall of the lens barrel, the air inlet and the air outlet are opened on the side wall of the lens barrel opposite to the mounting port, after the fixing bracket is inserted into the cylindrical cavity along the mounting port, the front end of the fixing bracket abuts against the side wall between the air inlet and the air outlet, and there are gaps between the left and right sides of the fixing bracket and the inner wall of the cylindrical cavity to form the air inlet section and the air outlet section respectively.

[0012] In one exemplary embodiment, the system further includes an air pump connected to the air inlet and the air outlet via an air pipe, for actively delivering gas into the cavity and causing the gas to flow in through the air inlet section, bypass the fixture and optical element, and then be discharged through the air outlet section.

[0013] In an exemplary embodiment, the air exchange flow rate of the air pump is not less than 60 L / min.

[0014] In one exemplary embodiment, the mounting bracket has mounting holes for fixing the liquid crystal polymer optical element, and the liquid crystal polymer optical element is fixed in the mounting holes by a retaining ring.

[0015] In an exemplary embodiment, the mounting bracket has a flow-guiding chamfer on the side facing the air inlet and the air outlet to guide the gas flow.

[0016] In one exemplary embodiment, the liquid crystal polymer optical element includes a sapphire substrate and a liquid crystal polymer film disposed on the sapphire substrate.

[0017] In one exemplary embodiment, the lens barrel and / or the mounting bracket are made of aluminum alloy.

[0018] The present invention achieves the following technical effects compared to the prior art: 1. Achieves reliable fixation and optical path sealing protection for optical components: The lens barrel has a cavity with a laser channel for laser transmission and a mounting port for inserting optical components. The mounting bracket is set inside the lens barrel cavity through the mounting port and is used to fix the liquid crystal polymer optical components. During use, the lens barrel can be connected to a laser emitter and a laser receiver to form a closed optical path. This achieves both stable installation of the liquid crystal polymer optical components and effectively prevents light leakage and contamination of the optical components by the sealed cavity, thus providing basic protection for the optical components.

[0019] 2. Achieves highly efficient active air cooling for optical components: The lens barrel has an inlet and an outlet for gas entry and exit, which are used to connect to an external gas source. A mounting bracket separates the cavity on one side where the inlet and outlet are located, creating isolated inlet and outlet sections. A gap is provided between the mounting bracket and the inner wall of the cavity to allow gas to flow around it. This design ensures that cooling gas supplied by the external gas source, after entering through the inlet, must flow around the mounting bracket and the optical components fixed to it through the gap between the mounting bracket and the inner wall of the cavity before exiting through the outlet, preventing a short circuit caused by the airflow directly from the inlet to the outlet. During this flow, the cooling gas passes over the surface of the optical components, carrying away the heat generated by laser irradiation and effectively reducing the operating temperature of the optical components.

[0020] 3. Significantly improved laser damage threshold of liquid crystal polymer optical elements: The active ventilation and heat dissipation achieved through the aforementioned lens barrel and mounting frame design effectively prevents excessively high local temperatures within the cavity, thereby increasing the damage threshold of the liquid crystal polymer optical elements. Under conditions of 1064 nm wavelength laser irradiation and a spot size of 13 mm, the maximum damage power of the liquid crystal polymer optical elements without this device was 900 W; with this device, under the same laser parameters, the damage threshold significantly increased to 2000 W. This significant increase in threshold is mainly attributed to the significant reduction in the overall operating temperature of the device due to the flow of cooling gas within the cavity.

[0021] 4. Simple structure, easy to manufacture and assemble: The lens barrel and mounting bracket can be manufactured using conventional metal materials such as aluminum alloy. The relative positions of the mounting port and the air inlet and outlet allow the mounting bracket to be inserted and installed through the mounting port on the side wall of the lens barrel, simplifying the assembly process and making it suitable for mass production and widespread application. Furthermore, the design of the air inlet and outlet for connecting to an external air source allows users to select different specifications of air pumps according to their actual needs, reducing the cost of the smallest selling unit while improving the versatility and flexibility of the device. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a liquid crystal polymer optical element protective fixing device disclosed in a specific embodiment of the present invention; Figure 2 for Figure 1 A structural diagram from another angle; Figure 3 for Figure 1 The main view; Figure 4 for Figure 1 Schematic diagram of the middle tube; Figure 5 for Figure 4 The main view; Figure 6 for Figure 5 Sectional view along axis AA; Figure 7 for Figure 1 Schematic diagram of the middle fixed frame; Figure 8 for Figure 7 A sectional view; Figure 9 for Figure 2 A schematic diagram of the structure of a liquid crystal polymer optical element; Figure 10 This is a simulation diagram of conjugate heat transfer between a solid and a fluid. Among them, 1 is the lens barrel; 101 is the cavity; 102 is the mounting port; 103 is the air inlet; 104 is the air outlet; 2 is the mounting bracket; 201 is the mounting hole; 202 is the air guide chamfer; 3 is the liquid crystal polymer optical element; 301 is the sapphire substrate; 302 is the liquid crystal polymer film. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The purpose of this invention is to provide a protective fixing device for liquid crystal polymer optical elements to solve the problems existing in the prior art. It forces cooling gas to flow through the surface of the optical element to achieve efficient active air cooling and heat dissipation, thereby significantly improving the damage threshold of liquid crystal polymer optical elements under high-power laser irradiation and meeting the usage requirements of high-power laser application scenarios.

[0026] To make the above-mentioned objects, features and advantages of the present invention more readily understood, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Please refer to Figures 1 to 9This embodiment provides a protective fixing device for liquid crystal polymer optical elements, mainly including a lens barrel 1 and a fixing frame 2. The lens barrel 1 forms a cavity 101, which is used to accommodate the fixing frame 2 and the liquid crystal polymer optical element 3 fixed thereon, and provides space for the flow of cooling gas. The lens barrel 1 is provided with a laser channel for laser to pass through, a mounting port 102 for the optical element to be installed, and an air inlet 103 and an air outlet 104 for gas to enter and exit. The air inlet 103 and the air outlet 104 are used to connect to an external air source, such as an air pump, compressed air pipeline, etc., to realize active ventilation inside the cavity 101.

[0028] The cavity 101 of the mirror tube 1 is preferably cylindrical. The cylindrical structure facilitates the formation of a swirling flow of gas within the cavity, maximizing the heat removal effect. The laser channel includes two light-transmitting holes located at the front and rear ends of the mirror tube 1, respectively. These two holes are coaxially arranged to allow the laser to pass axially through the cavity 101 of the mirror tube 1. In operation, the front end of the mirror tube 1 is connected to the laser emitter, and the rear end is connected to the laser receiver, forming a completely opaque, closed optical path. During testing, the liquid crystal polymer optical element 3 is placed on this optical path. The mirror tube 1 is preferably made of aluminum alloy. Aluminum alloy has advantages such as light weight, good machinability, and high thermal conductivity, which facilitates machining and helps conduct heat from the cavity to the external environment.

[0029] The mounting bracket 2 is disposed within the cavity 101 of the lens barrel 1 via the mounting port 102. Specifically, the mounting port 102 is formed on the side wall of the lens barrel 1, and its shape and size match the shape of the mounting bracket 2 so that the mounting bracket 2 can be inserted into the cavity 101 of the lens barrel 1 along the mounting port 102. The mounting bracket 2 is used to fix the liquid crystal polymer optical element 3, and its specific structure will be described in detail below.

[0030] The mounting bracket 2 divides the cavity 101 on the side where the air inlet 103 and air outlet 104 are located, so that the air inlet 103 and air outlet 104 are located on both sides of the mounting bracket 2, forming mutually isolated air inlet and air outlet sections. The air inlet 103 and air outlet 104 are preferably located on the side wall of the lens barrel 1 opposite to the mounting port 102. When the mounting bracket 2 is inserted into the cylindrical cavity 101 along the mounting port 102, the front end of the mounting bracket 2 (i.e., the end near the air inlet 103 and air outlet 104) abuts against the side wall between the air inlet 103 and air outlet 104, thereby dividing the cavity 101 into two mutually isolated parts—the air inlet section and the air outlet section—in the area where the air inlet 103 and air outlet 104 are located. Simultaneously, there are gaps between the left and right sides of the mounting bracket 2 and the inner wall of the cylindrical cavity 101 to form extensions of the air inlet and air outlet sections, respectively.

[0031] The advantages of the above structure are as follows: Airflow with sufficient initial velocity enters through the inlet 103, enters the intake section under the separation effect of the mounting bracket 2, flows along the gap on one side of the mounting bracket 2 into the cylindrical cavity 101, reaches the mounting bracket 2, bypasses the mounting bracket 2 and the liquid crystal polymer optical element 3 fixed thereon, and then flows along the gap on the other side of the mounting bracket 2 towards the exhaust section, finally exiting from the exhaust port 104. This design prevents the airflow from directly flowing from the inlet 103 to the exhaust port 104, forming a short circuit. Instead, the airflow is forced to flow across the surfaces of the mounting bracket 2 and the optical element 3, thereby maximizing the removal of heat generated by the optical element 3 under laser irradiation. Simultaneously, the inner wall of the cylindrical cavity 101 can guide the airflow, causing the gas to swirl within the cavity 101, further enhancing the heat dissipation effect.

[0032] The material of the mounting bracket 2 is preferably aluminum alloy, which is the same as the material of the lens barrel 1. This is beneficial for matching the coefficient of thermal expansion and avoids thermal stress caused by temperature changes from damaging the installation accuracy of the optical components.

[0033] The liquid crystal polymer optical element 3 is fixed on the mounting bracket 2. Specifically, the mounting bracket 2 has a mounting hole 201 for fixing the liquid crystal polymer optical element 3. The axial direction of the mounting hole 201 is consistent with the axial direction of the laser channel to ensure that the laser can pass through the liquid crystal polymer optical element 3 perpendicularly.

[0034] The liquid crystal polymer optical element 3 includes a sapphire substrate 301 and a liquid crystal polymer film 302 disposed on the sapphire substrate 301. Sapphire has extremely high thermal conductivity (approximately 30 times that of quartz glass). Choosing sapphire as the substrate material allows for rapid conduction of heat generated by the liquid crystal polymer film 302 under laser irradiation, preventing heat accumulation in the film and thus avoiding overheating. The liquid crystal polymer film 302 is fabricated on the sapphire substrate 301 using a coating process. In one specific embodiment, the S1 side (facing the laser incident direction) of the sapphire substrate 301 is coated with an antireflection film, with the following optical parameters: Ravg < 0.5% @ 400-460 nm; Rabs < 0.25% @ 532 nm @ 1030-1090 nm; Rabs < 0.2% @ 1080 nm; the S2 side (facing away from the laser incident direction) is uncoated. The transmitted wavefront (both S1 and S2 sides) reaches λ / 10 @ 632.8 nm. The substrate has a diameter of 29.9 mm and a thickness of 1.6 mm. The above coating parameters and substrate dimensions are only one specific implementation of the present invention. Those skilled in the art can make adaptive adjustments to the coating scheme and substrate dimensions according to the actual laser wavelength, power, and other parameters used.

[0035] The liquid crystal polymer optical element 3 is fixed in the mounting hole 201 of the mounting bracket 2 by a metal retainer. Specifically, the outer edge of the metal retainer engages with the inner wall of the mounting hole 201, and the inner edge of the metal retainer presses the edge of the liquid crystal polymer optical element 3 against the mounting bracket 2, thereby achieving axial and radial positioning of the optical element. Using a metal retainer to fix the optical element is a conventional technique well known to those skilled in the art, and will not be described in detail here.

[0036] To further improve the efficiency of cooling gas flow across the surface of the optical element, a guide chamfer 202 is provided on the side of the mounting bracket 2 facing the air inlet 103 and the air outlet 104. The function of the guide chamfer 202 is to guide the airflow after it enters the cavity 101 from the air inlet 103, reduce the airflow resistance, and allow the airflow to flow more smoothly along the surface of the mounting bracket 2 to the area where the optical element 3 is located, thereby improving the heat dissipation efficiency.

[0037] Two transparent partitions, allowing laser light to pass through, are installed at the two light-transmitting holes of the lens barrel 1 to seal the cavity 101 and prevent gas leakage. The transparent partitions are made of a material with high transmittance to the working laser wavelength (e.g., 1064nm), such as quartz glass or other suitable optical window materials. The transparent partitions create a relatively sealed space within the cavity 101 of the lens barrel 1. Cooling gas supplied by an external gas source can only enter the cavity 101 through the inlet 103 and exit through the outlet 104, without leaking from the light-transmitting holes. This ensures that the cooling gas flows within the cavity 101 along a predetermined path, maximizing heat dissipation. Using transparent partitions to seal the optical cavity and prevent gas leakage is a mature existing technology in this field. Those skilled in the art can select appropriate transparent partition materials and sealing methods according to actual needs.

[0038] In a preferred embodiment of the present invention, the protective fixing device further includes an air pump. The air pump is connected to the air inlet 103 and the air outlet 104 via an air pipe, and is used to actively deliver gas into the cavity 101, allowing the gas to flow in through the air inlet section, bypass the fixing frame 2 and the optical element 3, and then be discharged through the air outlet section. The specific model of the air pump is not limited, as long as it can provide sufficient gas flow. As a specific implementation, the air pump can be an oil-free high-efficiency air compressor of model Dongcheng Q1E-FF-1200 / 50L, which has an air exchange rate of up to 60L / min.

[0039] The inventors conducted a systematic study on the relationship between the airflow rate of active ventilation and the overall temperature of the device. Without active ventilation (airflow rate of 0 L / min), the device temperature reached 87°C under irradiation by a 1064 nm wavelength laser with a spot size of 13 mm and a laser power of 900 W. As the airflow rate increased, the device temperature gradually decreased: to 72°C at 10 L / min, to 58°C at 20 L / min, to 52°C at 40 L / min, and to 45°C at 60 L / min. Based on these results, and considering the phase transition temperature of the liquid crystal polymer material (approximately 50°C for long-term stable operation), a gas flow rate of 60 L / min was determined. When active ventilation reaches this flow rate, the liquid crystal polymer optical element 3 can operate normally under high-power laser irradiation with a spot size of 13 mm and a light intensity of 2000 W.

[0040] The cooling effect primarily depends on the gas flow rate—a higher flow rate means more heat generated by laser irradiation on the optical components is removed, which is certain. Simultaneously, the cross-sectional area of ​​the airflow channel inside the cylindrical cavity 101 also affects the flow velocity: given a constant flow rate, a smaller cross-sectional area (i.e., a smaller gap between the fixture 2 and the inner wall of the cavity 101) results in a faster flow velocity, leading to faster heat removal and thus a better cooling effect. With a constant overall flow rate, a higher local airflow velocity near the liquid crystal polymer optical component 3 results in better heat dissipation.

[0041] The working principle and beneficial effects of the present invention will be explained below in conjunction with the overall structure and working process of the device.

[0042] In use, the liquid crystal polymer optical element 3 is fixed in the mounting hole 201 of the mounting bracket 2 using a metal retainer. Then, the mounting bracket 2 is inserted into the cylindrical cavity 101 along the mounting opening 102 of the lens barrel 1. After insertion, the front end of the mounting bracket 2 abuts against the side wall between the air inlet 103 and the air outlet 104, dividing the area where the air inlet 103 and the air outlet 104 are located into mutually isolated air inlet and air outlet sections. There is also a gap between the mounting bracket 2 and the inner wall of the cavity 101 for gas to flow around. The front end of the lens barrel 1 is connected to the laser emitter, and the rear end is connected to the laser receiver, forming a closed optical path. The transparent partitions at the two light-transmitting holes seal the cavity 101 to prevent gas leakage. An external gas source (such as an air pump) is connected to the air inlet 103 and the air outlet 104 through an air pipe to actively deliver cooling gas into the cavity 101.

[0043] After entering the cavity 101 through the inlet 103, the cooling gas, guided by the separation effect of the mounting bracket 2 and the flow-guiding chamfer 202, enters the inlet section. It flows into the cavity 101 along the gap on one side of the mounting bracket 2, then bypasses the mounting bracket 2 and the liquid crystal polymer optical element 3 fixed thereon, flowing over the surface of the optical element 3 and carrying away the heat generated under laser irradiation. Subsequently, the airflow flows to the outlet section along the gap on the other side of the mounting bracket 2, and finally exits the cavity 101 through the outlet 104. Throughout the flow process, the inner wall of the cylindrical cavity 101 guides the airflow, causing the gas to swirl within the cavity 101, thus maximizing the heat removal effect.

[0044] Through the synergistic structural design of the lens barrel 1 and the fixing frame 2 described above, the present invention achieves the following beneficial effects: First, reliable fixation and optical path sealing protection of the liquid crystal polymer optical element 3 are achieved. The lens barrel 1 forms a cavity 101 with a laser channel for laser transmission and a mounting port 102 for the optical element to be installed. The mounting bracket 2 is set in the cavity 101 through the mounting port 102 and is used to fix the liquid crystal polymer optical element 3. When in use, the lens barrel 1 connects the laser emitter and the laser receiver to form a closed optical path, which not only achieves stable installation of the liquid crystal polymer optical element 3, but also effectively prevents light leakage and contamination of the optical element 3 by sealing the cavity 101, thus achieving basic protection for the optical element 3.

[0045] Secondly, efficient active air cooling of the optical element 3 is achieved. The lens barrel 1 has an air inlet 103 and an air outlet 104 for gas entry and exit, which are used to connect to an external air source. The mounting bracket 2 separates the cavity 101 on the side where the air inlet 103 and air outlet 104 are located, so that the air inlet 103 and air outlet 104 are located on opposite sides of the mounting bracket 2, forming mutually isolated air inlet and outlet sections. Simultaneously, a gap is provided between the mounting bracket 2 and the inner wall of the cavity 101 to allow gas to flow around the mounting bracket 2. This structural design ensures that the cooling gas supplied by the external air source, after entering through the air inlet 103, must bypass the mounting bracket 2 and the liquid crystal polymer optical element 3 fixed thereon along the gap between the mounting bracket 2 and the inner wall of the cavity 101 before exiting through the air outlet 104, preventing a short circuit caused by the airflow directly flowing from the air inlet 103 to the air outlet 104. As the cooling gas flows around the surface of the liquid crystal polymer optical element 3, it carries away the heat generated by the laser irradiation in a timely manner, thereby effectively reducing the operating temperature of the optical element 3.

[0046] Third, the laser damage threshold of the liquid crystal polymer optical element 3 is significantly improved. The active ventilation and heat dissipation achieved through the structural design of the lens barrel 1 and the mounting bracket 2 effectively prevents excessively high local temperatures in the cavity 101, thereby increasing the damage threshold of the liquid crystal polymer optical element 3. Compared to before using this device, the maximum damage power of the liquid crystal polymer optical element 3 under 1064nm wavelength laser irradiation and a 13mm spot size was 900W; after using this device, under the same laser parameters, the damage threshold significantly increased to 2000W. This significant increase in threshold is mainly attributed to the significant reduction in the overall operating temperature of the device due to the airflow within the cavity 101.

[0047] Fourth, the structure is simple and easy to manufacture and assemble. The lens barrel 1 and the mounting bracket 2 can be manufactured using conventional metal materials such as aluminum alloy. The relative position design of the mounting port 102 with the air inlet 103 and air outlet 104 allows the mounting bracket 2 to be inserted and installed through the mounting port 102 on the side wall of the lens barrel 1, simplifying the assembly process and making it suitable for mass production and widespread application. Meanwhile, the design of the air inlet 103 and air outlet 104 for connecting to an external air source allows users to select different specifications of air pumps according to their actual needs, reducing the cost of the smallest selling unit and improving the versatility and flexibility of the device.

[0048] The inventors used COMSOL Multiphysics software to perform solid-fluid conjugate heat transfer simulations on the structure to verify the effectiveness of the above design. The simulation conditions were set as follows: gas flow rate 60 L / min, laser spot diameter 13 mm, and laser power 2000 W. The simulation results are as follows. Figure 10 As shown in the figure, the colors of the temperature bars on the left correspond to the temperature distribution of the physical components of the lens barrel 1, the mounting bracket 2, and the liquid crystal polymer optical element 3, while the colors of the flow velocity bars on the right correspond to the color distribution of the airflow arrows. Simulation results show that the highest temperature of the entire device meets the requirement that the liquid crystal polymer optical element 3 can operate stably for a long time at 50℃. Simultaneously, the simulation results also clearly demonstrate the gas flow path within the cavity 101—after entering through the inlet 103, the airflow flows into the cylindrical cavity 101, and under the guidance of the inner wall of the cavity 101, bypasses the mounting bracket 2 and the optical element 3 before flowing to the outlet 104, verifying the rationality of the aforementioned airflow channel design.

[0049] It should be noted that the specific embodiments described in the above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0050] For example, the materials of the lens barrel 1 and the mounting bracket 2 are not limited to aluminum alloy; other metal materials with good thermal conductivity and machinability, such as copper alloy and stainless steel, can also be used. The substrate material of the liquid crystal polymer optical element 3 is not limited to sapphire; other optical materials with high thermal conductivity, such as silicon carbide and diamond, can also be used. The specific model of the gas pump is not limited to Dongcheng Q1E-FF-1200 / 50L; any gas source device capable of providing sufficient gas flow can be used. The material of the transparent partition is not limited to quartz glass; other materials with high transmittance to the working laser wavelength can also be used. Furthermore, the dynamic phase optical element prepared based on quartz etching and femtosecond modification can greatly improve the material's damage threshold, and the use of a large-area partition with complete protection can reduce safety hazards in the use of infrared high-power lasers. These can all be considered as alternatives or supplements to this invention.

[0051] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention, and do not imply or require that the device or element referred to have a specific orientation or construction method, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish the objects of description and should not be construed as limiting importance or order, and the features defined by such terms may explicitly or implicitly include one or more of those features. Unless otherwise stated, "a plurality of" in the description of this invention refers to two or more.

[0052] The terms "installation," "connection," and "joining" should be interpreted broadly, unless otherwise explicitly defined, to include, but are not limited to, fixed connections, detachable connections, or integrally formed connections; mechanical or electrical connections; direct connections or indirect connections via an intermediate medium; and internal communication between two components. Those skilled in the art can understand their meaning based on the specific technical solution. The fixed connections involved in this invention, unless otherwise stated, include both detachable fixed connections (such as bolt and screw connections) and non-detachable fixed connections (such as riveting and welding), and may also include integral structures achieved through an integral forming process (such as casting) (except where integral forming is clearly impossible).

[0053] Unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes cover states or shapes that are similar to, close to, or adjacent to them.

[0054] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process.

[0055] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0056] In the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0057] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0058] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A protective fixing device for liquid crystal polymer optical elements, characterized in that, include: The mirror tube (1) has a cavity (101) and is provided with a laser channel for laser to pass through, an installation port (102) for optical elements to be installed, and an air inlet (103) and an air outlet (104) for gas to enter and exit. The air inlet (103) and the air outlet (104) are used to connect to an external gas source. A mounting bracket (2) is installed in the cavity (101) of the lens barrel (1) through the mounting port (102). The mounting bracket (2) is used to fix the liquid crystal polymer optical element. The mounting bracket (2) separates the cavity (101) on the side where the air inlet (103) and the air outlet (104) are located, so that the air inlet (103) and the air outlet (104) are located on both sides of the mounting bracket (2) to form mutually isolated air inlet section and air outlet section. A gap is provided between the mounting bracket (2) and the inner wall of the cavity (101) for gas to flow around the mounting bracket (2).

2. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: The cavity (101) of the lens tube (1) is a cylindrical cavity. The laser channel includes two light-transmitting holes respectively opened at the front end and the rear end of the lens tube (1). The two light-transmitting holes are coaxially arranged so that the laser can pass through along the axial direction.

3. The protective fixing device for liquid crystal polymer optical elements according to claim 2, characterized in that: Both of the light-transmitting holes are equipped with transparent partitions that allow laser light to pass through, which are used to seal the cavity (101) to prevent gas leakage.

4. The protective fixing device for liquid crystal polymer optical elements according to claim 2, characterized in that: The mounting port (102) is opened on the side wall of the lens barrel (1). The air inlet (103) and the air outlet (104) are opened on the side wall of the lens barrel (1) opposite to the mounting port (102). After the fixing bracket (2) is inserted into the cylindrical cavity (101) along the mounting port (102), the front end of the fixing bracket (2) abuts against the side wall between the air inlet (103) and the air outlet (104). There are gaps between the left and right sides of the fixing bracket (2) and the inner wall of the cylindrical cavity (101) to form the air inlet section and the air outlet section respectively.

5. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: It also includes an air pump, which is connected to the air inlet (103) and the air outlet (104) via an air pipe, for actively delivering gas into the cavity (101) and causing the gas to flow in through the air inlet section, bypass the fixing frame (2) and the optical element, and then be discharged through the air outlet section.

6. The protective fixing device for liquid crystal polymer optical elements according to claim 5, characterized in that: The air exchange flow rate of the air pump is not less than 60 L / min.

7. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: The mounting bracket (2) has a mounting hole (201) for fixing the liquid crystal polymer optical element, and the liquid crystal polymer optical element is fixed in the mounting hole (201) by a retaining ring.

8. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: The mounting bracket (2) has a flow guide chamfer (202) on the side facing the air inlet (103) and the air outlet (104) to guide the gas flow.

9. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: The liquid crystal polymer optical element (3) includes a sapphire substrate (301) and a liquid crystal polymer film (302) disposed on the sapphire substrate (301).

10. The protective fixing device for liquid crystal polymer optical elements according to claim 1, characterized in that: The lens barrel (1) and / or the mounting bracket (2) are made of aluminum alloy.

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