A double-beam dynamic regulation laser powder sintering device for preparing rare earth doped quartz glass

Abstract

The application provides a double-beam dynamic regulation laser powder sintering device for preparation of rare earth doped quartz glass. The device comprises a laser one, a laser two, a dynamic angle regulation system, a coaxial airflow coating powder feeding system, a sealed sintering chamber and a liftable ultrasonic vibration rotary base rod. The dynamic angle regulation system is composed of an angle adjustable mirror one, an angle adjustable mirror two, an angle adjustable mirror three and an angle adjustable mirror four. The liftable ultrasonic vibration rotary base rod is composed of a quartz base rod, a liftable platform, a stepping motor, a coupling, an ultrasonic transducer one and an ultrasonic transducer two. The double-beam dynamic regulation laser powder sintering device for preparation of rare earth doped quartz glass realizes continuous and high-quality preparation of the rare earth doped quartz glass, and improves the density, optical uniformity and optical performance of the glass.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing and fiber optic material preparation technology, specifically to a dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass. Background Technology

[0002] Rare-earth-doped quartz glass is a core material for gain fibers in high-power fiber lasers, and its performance directly determines key indicators such as output power, energy conversion efficiency, and fluorescence lifetime of fiber lasers. Currently, the main methods for preparing rare-earth-doped quartz glass include chemical vapor deposition (CVD), sol-gel methods combined with laser melting, etc. Among these, laser sintering technology is widely used in the preparation of rare-earth-doped quartz glass due to its advantages such as concentrated heating, rapid heating rate, low energy consumption, and effective prevention of material crystallization.

[0003] Existing laser sintering devices for preparing rare-earth-doped quartz glass have the following shortcomings:

[0004] The laser beam incident angle is fixed and cannot be dynamically adjusted according to the powder deposition height and the rotation state of the base rod. It is difficult to adapt to the heating requirements of different sintering stages, resulting in unstable sintering quality. Furthermore, it lacks flexible adjustment of laser beam incident conditions when preparing glass rods of different sizes.

[0005] Existing powder deposition methods mostly involve non-coaxial powder feeding or spreading, resulting in low powder utilization and susceptibility to external interference, leading to uneven deposition and defects such as bubbles and stratification.

[0006] The lack of an auxiliary flow mechanism results in insufficient fluidity of the glass melt during sintering, which easily leads to residual bubbles and pores, reducing the glass density and affecting optical performance.

[0007] Therefore, developing a dual-beam dynamically controlled laser powder sintering device that can solve the above problems and meet the needs of rare earth doped quartz glass preparation is of great practical significance and application value. Summary of the Invention

[0008] The purpose of this invention is to propose a dual-beam dynamically controlled laser powder sintering device for the preparation of rare earth-doped quartz glass, thereby solving the problems of existing devices such as the inflexible adjustment of laser incident angle and spot distribution, limited glass rod size, lack of fluidity of powder melt, and low powder utilization. Through dual-beam laser complementarity, multi-angle dynamically adjustable optical path, coaxial carrier gas powder delivery, and ultrasonic micro-vibration mechanism, continuous and high-quality preparation of rare earth-doped quartz glass can be achieved, improving the density, optical uniformity, and optical performance of the glass.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A dual-beam dynamically controlled laser powder sintering device for the preparation of rare earth doped quartz glass includes a laser I, a laser II, a dynamic angle control system, a coaxial airflow encapsulation powder feeding system, a sealed sintering chamber, and a liftable ultrasonic vibration rotating base rod.

[0011] The dynamic angle control system consists of an angle-adjustable reflector one, an angle-adjustable reflector two, an angle-adjustable reflector three, and an angle-adjustable reflector four, used to control the dynamic adjustment of the laser beam angle and the distribution of the laser spot in the melting zone.

[0012] The liftable ultrasonic vibration rotating base rod consists of a quartz base rod for forming a molten zone under laser action and carrying powder and sintered glass rods, a liftable platform for controlling the lifting and lowering movement of the quartz base rod, a stepper motor for adjusting the rotation speed of the quartz base rod to achieve different laser scanning speeds, a coupling, and ultrasonic transducers one and two for generating micro-vibrations that are transmitted to the quartz base rod. The coupling is used to connect the stepper motor and the quartz base rod, and ultrasonic transducers one and two help to enhance the fluidity of the melt and effectively remove internal bubbles.

[0013] The coaxial airflow enveloping powder delivery system includes a powder storage bin, interconnected gas cylinders, an air inlet, a coaxial powder delivery pipe, and a powder agitator. The interconnected gas cylinders deliver gas to the powder storage bin through the air inlet and the coaxial powder delivery pipe. The powder agitator is located inside the powder storage bin.

[0014] The sealed sintering chamber includes a sealed chamber, a laser incident window one and a laser incident window two located on both sides of the sealed chamber, and the sealed sintering chamber is used for the sealed sintering of rare earth doped quartz glass.

[0015] As a further improvement, the coaxial airflow enveloping powder delivery system includes a powder storage bin, a coaxial powder delivery pipe, and a powder agitator; the powder storage bin stores rare earth-doped quartz powder for laser sintering, and the powder agitator is used to lift and suspend the powder in the storage bin.

[0016] As a further improvement, the sealed sintering chamber includes a sealed chamber, a laser incident window one and a laser incident window two located on both sides of the sealed chamber; the function of the sealed chamber is to form a sintering environment filled with protective gas.

[0017] As a further improvement, both laser one and laser two are CO2 lasers with an operating wavelength of 10-11 μm; furthermore, the operating wavelength is 10.6 μm.

[0018] As a further improvement, the coaxial powder feeding tube is set coaxially with the quartz base rod, so that the powder is accurately deposited on the top of the quartz base rod and powder waste is avoided.

[0019] As a further improvement, the angle-adjustable reflector 1, angle-adjustable reflector 2, angle-adjustable reflector 3, and angle-adjustable reflector 4 are all molybdenum reflector groups;

[0020] The angle-adjustable reflector one and angle-adjustable reflector three are placed together in the optical path of laser one.

[0021] The second and fourth angle-adjustable reflectors are another set, placed in the optical path of the second laser.

[0022] As a further improvement, the sealed sintering chamber also includes an observation window; the observation window is located on the front of the sealed sintering chamber and is used to observe the sintering state inside the chamber.

[0023] As a further improvement, the gas inside the cylinder is either O2 or N2.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The dual-laser synergistic complementary heating and dynamic angle control system of laser one and laser two has adjustable dynamic angle, which greatly improves heating uniformity and adaptability: carbon dioxide laser one and carbon dioxide laser two provide the main melting heat. The two lasers are incident from different angles, and the incident angle can be flexibly adjusted by the dynamic angle adjustment optical path of the dynamic angle control system. It can be dynamically adjusted according to the sintering stage and deposition height to ensure uniform temperature in the melting heating zone, avoid local overheating or excessively rapid cooling, and improve the optical uniformity of the glass.

[0026] 2. Coaxial airflow enveloping powder feeding system: Coaxial powder feeding and gas carrying result in uniform powder deposition and high utilization rate. The coaxial powder feeding tube is set coaxially with the quartz base rod, and the powder is accurately deposited in the melting heating zone under the carrying of oxygen, avoiding the powder waste and uneven deposition problems of non-coaxial powder feeding. At the same time, the protective gas atmosphere can help the powder dehydrate and remove organic matter, reduce the glass hydroxyl content, and avoid ytterbium ion valence change, further improving the sintering quality.

[0027] 3. Ultrasonic-assisted vibration effectively improves glass density: The micro-vibrations generated by ultrasonic transducers one and two are transmitted to the molten glass zone, enhancing melt fluidity, effectively removing internal bubbles and pores, reducing defects, significantly improving the density of ytterbium-doped quartz glass, and improving its optical and mechanical properties.

[0028] 4. Liftable ultrasonic vibration rotating base rod for continuous glass rod growth: The stepper motor drives the quartz rod to rotate at a uniform speed, achieving uniform laser scanning; the liftable platform can be controlled to descend synchronously with the deposition height, ensuring that the molten heating zone is always at the laser focusing target point, eliminating the need for mid-process stoppages for adjustment, thus achieving continuous glass rod growth and significantly improving preparation efficiency and product size consistency.

[0029] 5. The structure is reasonably designed, and all systems work together, making it easy to operate and monitor; the heat preservation and sealing design of the sealed chamber ensures a stable sintering environment and further improves the quality of quartz glass.

[0030] 6. High versatility and adaptability to different preparation needs: By adjusting laser parameters, powder feeding rate, scanning rate, and lifting rate, it can adapt to the preparation needs of quartz glass rods with different diameters, different doping concentrations, and different doping elements. It has a wide range of applications and broad application prospects. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass.

[0032] Among them, 1-Laser 1; 2-Laser 2; 3-Angle adjustable reflector 1; 4-Angle adjustable reflector 2; 5-Angle adjustable reflector 3; 6-Angle adjustable reflector 4; 7-Powder storage bin; 8-Gas cylinder; 9-Air inlet; 10-Coaxial powder delivery pipe; 11-Powder stirrer; 12-Sealed chamber; 13-Laser incident window 1; 14-Laser incident window 2; 15-Observation window; 16-Liftable platform; 17-Stepper motor; 18-Coupling; 19-Quartz base rod; 20-Ultrasonic transducer 1; 21-Ultrasonic transducer 2. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0034] like Figure 1As shown, the dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass provided by the present invention comprises a laser 1, a laser 2, a dynamic angle control system, a coaxial airflow enveloping powder delivery system, a sealed sintering chamber, and a liftable ultrasonic vibration rotating base rod; the dynamic angle control system comprises an angle-adjustable reflector 3, an angle-adjustable reflector 4, an angle-adjustable reflector 3, an angle-adjustable reflector 5, and an angle-adjustable reflector 4, and an angle-adjustable reflector 6; the coaxial airflow enveloping powder delivery system comprises a powder storage bin 7, a gas cylinder 8 and an air inlet 9, a coaxial powder delivery pipe 10, and a powder stirrer 11; the sealed sintering chamber comprises a sealed chamber 12. The system consists of a laser incident window 13 and a laser incident window 14 located on both sides of the sealed chamber 12, and an observation window 15. The liftable ultrasonic vibration rotating base rod consists of a quartz base rod 19 used to form a molten zone under laser action and to carry powder and sintered glass rods, a liftable platform 16 for controlling the lifting and lowering movement of the quartz base rod 19, a stepper motor 17 for adjusting the rotation speed of the quartz base rod 19 to achieve different laser scanning speeds, a coupling 18, and ultrasonic transducers 20 and 21 that generate micro-vibrations and transmit them to the quartz base rod 19. The coupling 18 is used to connect the stepper motor 17 and the quartz base rod 19.

[0035] The working principle is as follows:

[0036] The laser beams emitted by laser 1 and laser 2 serve as heat sources. After being reflected by the angle-adjustable reflectors 3, 4, 5, and 6 of the dynamic angle control system, the laser beams enter through the laser incident windows 13 and 14 on both sides of the sealed chamber 12, irradiating the top of the rotating micro-vibrating quartz rod 19 and forming a high-temperature melting zone. The laser power of laser 1 and laser 2 is adjustable to meet different temperature requirements of the melting zone, and the angles of the angle-adjustable reflectors 3, 4, 5, and 6 are adjustable to meet the dynamic control of the incident angle and spot distribution of the laser beam.

[0037] Rare earth doped stone powder stored in powder storage bin 7 is suspended in the bin by the agitator 11. Gas cylinder 8 continuously supplies gas through inlet 9. The suspended powder is carried by the airflow and precisely deposited into the molten zone at the top of the quartz base rod 19 through the coaxial powder delivery pipe 10. Under the action of a high-energy laser beam, it is transformed into quartz glass. The powder delivery rate can be adjusted by adjusting the agitator speed and the airflow. At the same time, the carrier gas can form a protective atmosphere in the sealed chamber.

[0038] The quartz base rod 19 is connected to the shaft of the stepper motor 17 via a coupling 18. By adjusting the speed of the stepper motor, the laser scanning speed can be controlled. Ultrasonic transducers 20 and 21 transmit micro-vibrations to the molten glass region at the top of the quartz rod, enhancing the fluidity of the glass melt, reducing residual bubbles inside the melt, and increasing the glass density. When the powder is deposited to a certain height, the adjustable platform 16 is adjusted to lower the quartz base rod by the corresponding height, so that the laser beam always irradiates the top of the quartz base rod, and the sintered quartz glass continuously increases in height.

[0039] The aforementioned laser 1, laser 2, dynamic angle control system, coaxial airflow encapsulation powder delivery system, sealed sintering chamber, and liftable ultrasonic vibration rotating base rod work together to achieve continuous laser sintering preparation of rare earth doped quartz glass.

[0040] For example, the present invention provides the following embodiment one:

[0041] Turn on laser 1 (a CO2 laser) with a power of 130W. Adjust the angle-adjustable reflector 3 (a molybdenum reflector) so that the laser beam emitted by laser 1 is reflected by the angle-adjustable reflector 3 to the angle-adjustable reflector 5 (a molybdenum reflector). Then adjust the angle-adjustable reflector 5 so that the laser beam shines on the center of the top of the quartz base rod 19 through the left laser entrance window 13. Turn on laser 2 (a CO2 laser) with a power of 130W. Adjust the angle-adjustable reflector 4 (a molybdenum reflector) so that the laser beam emitted by laser 2 is reflected by the molybdenum reflector to the angle-adjustable reflector 6 (a molybdenum reflector). Then adjust the angle-adjustable reflector 6 so that the laser beam shines on the top edge of the quartz base rod 19 through the left laser entrance window 14, tangentially distributed with the center spot. Set the stepper motor 17 speed to 20. At rpm, ultrasonic transducers 20 and 21 generate micro-vibrations at 50kHz; the valve of oxygen cylinder 8 is opened and powder stirrer 11 is started. Ytterbium-doped quartz powder is suspended in the powder storage chamber 7 and accurately deposited on the top melting zone of quartz base rod 19 under the oxygen carrying through coaxial powder delivery pipe 10, and quickly melts into a glassy state; after about 1mm of quartz glass is deposited in the melting zone, the liftable platform 16 is lowered by 1mm to continue sintering and melting subsequent powders. This step is repeated to finally prepare a ytterbium-doped quartz glass rod with a diameter of 12mm and a height of 35mm.

[0042] Tests showed that the ytterbium-doped quartz glass prepared in this embodiment is amorphous, free of crystallization defects, and meets the requirements for optical transparency. The hydroxyl content is 18.3 ppm, the fluorescence lifetime is 0.885 ms, and the transmittance in the visible light band is over 81%. All performance indicators meet the requirements for high-power fiber lasers.

[0043] For example, the present invention provides the following second embodiment:

[0044] Turn on laser 1 (a CO2 laser) at 150W. Adjust the angle-adjustable reflector 3 (a molybdenum reflector) so that the laser beam emitted by laser 1 is reflected by the angle-adjustable reflector 3 to the angle-adjustable reflector 5 (a molybdenum reflector). Then adjust the angle-adjustable reflector 5 so that the laser beam shines on the center of the top of the quartz base rod 19 through the left laser entrance window 13. Turn on laser 2 (a CO2 laser) at 150W. Adjust the angle-adjustable reflector 4 (a molybdenum reflector) so that the laser beam emitted by laser 2 is reflected by the molybdenum reflector to the angle-adjustable reflector 6 (a molybdenum reflector). Then adjust the angle-adjustable reflector 6 so that the laser beam shines on the top edge of the quartz base rod 19 through the left laser entrance window 14, tangentially distributed with the center spot. Set the stepper motor 17 speed to 25. At rpm, ultrasonic transducers 20 and 21 generate micro-vibrations at 50kHz; the valve of the nitrogen cylinder 8 is opened and the powder stirrer 11 is started. The neodymium-doped quartz powder in the powder storage chamber 7 is suspended in the chamber and accurately deposited on the top melting zone of the quartz base rod 19 through the coaxial powder delivery pipe 10 under the carrying of nitrogen gas, and quickly melts into a glassy state; after about 1mm of quartz glass is deposited in the melting zone, the liftable platform 16 is lowered by 1mm to continue sintering and melting the subsequent powder. This step is repeated to finally prepare a neodymium-doped quartz glass rod with a diameter of 10mm and a height of 40mm.

[0045] Tests showed that the ytterbium-doped quartz glass prepared in this embodiment is amorphous, free of crystallization defects, and meets the requirements for optical transparency. The hydroxyl content is 3.7 ppm, the fluorescence lifetime is 0.435 ms, and the transmittance in the visible light band is over 74%. All performance indicators meet the requirements for high-power fiber lasers.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass, characterized in that, The dual-beam dynamic control laser powder sintering device for the preparation of rare earth doped quartz glass includes a laser one (1), a laser two (2), a dynamic angle control system, a coaxial airflow encapsulation powder feeding system, a sealed sintering chamber, and a liftable ultrasonic vibration rotating base rod. The dynamic angle control system consists of an angle-adjustable reflector one (3), an angle-adjustable reflector two (4), an angle-adjustable reflector three (5) and an angle-adjustable reflector four (6), used to control the dynamic adjustment of the laser beam angle and the distribution of the laser spot in the melting zone; The liftable ultrasonic vibration rotating base rod consists of a quartz base rod (19) for forming a molten zone under laser action and carrying powder and sintered glass rods, a liftable platform (16) for controlling the lifting and lowering movement of the quartz base rod (19), a stepper motor (17) for adjusting the rotation speed of the quartz base rod (19) to achieve different laser scanning speeds, a coupling (18), an ultrasonic transducer one (20) and an ultrasonic transducer two (21) for generating micro-vibrations that are transmitted to the quartz base rod (19); the coupling (18) is used to connect the stepper motor (17) and the quartz base rod (19). The coaxial airflow enveloping powder delivery system includes a powder storage bin (7), interconnected gas cylinders (8), an air inlet (9), a coaxial powder delivery pipe (10), and a powder agitator (11). The interconnected gas cylinders (8) deliver gas through the air inlet (9) and the coaxial powder delivery pipe (10) to the powder storage bin (7). The powder agitator (11) is located inside the powder storage bin (7). The sealed sintering chamber includes a sealed chamber (12), a laser incident window one (13) and a laser incident window two (14) located on both sides of the sealed chamber (12), and the sealed sintering chamber is used for rare earth doped quartz glass sealing sintering. The coaxial powder feeding pipe (10) is coaxially arranged with the quartz base rod (19); The angle-adjustable reflector one (3), angle-adjustable reflector two (4), angle-adjustable reflector three (5), and angle-adjustable reflector four (6) are all molybdenum reflector groups; Both laser one (1) and laser two (2) are CO2 lasers with a working wavelength of 10-11 μm.

2. The dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass according to claim 1, characterized in that, The angle-adjustable reflector one (3) and the angle-adjustable reflector three (5) are a group and placed in the optical path of laser one (1); The angle-adjustable reflector two (4) and angle-adjustable reflector four (6) are another set, placed on the optical path of laser two (2).

3. The dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass according to claim 2, characterized in that, The sealed sintering chamber also includes an observation window (15).

4. The dual-beam dynamically controlled laser powder sintering device for the preparation of rare-earth-doped quartz glass according to claim 1, characterized in that, The gas in the gas cylinder (8) is O2 or N2.

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