Method and device for improving plasma light source brightness and ultraviolet intensity

Abstract

The invention discloses a method and device for improving the brightness and ultraviolet intensity of a plasma light source, and belongs to the technical field of plasma luminescence. The device comprises a laser emitting device, an optical element device, a gas sealing device, a plasma heating device and a power supply device, the optical element device is used for focusing laser to the center of the plasma, the gas sealing device is used for sealing high-pressure gas, the optical element device is located between the laser emitting device and the plasma, and the plasma heating device is embedded in the side wall of the gas sealing device. According to the device, the independent plasma heating device and main laser heating are introduced for cooperative work, active composite heating of the plasma is achieved, energy can be injected into the plasma more effectively through the synergistic effect, the core temperature and the electron density of the plasma are remarkably improved, and therefore the total radiation brightness of the light source is greatly enhanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plasma light emission, and particularly relates to a method and device for improving the brightness and ultraviolet intensity of a plasma light source. BACKGROUND

[0002] The light emission principle of a laser sustained plasma (LSP) light source is to use a laser beam focused by an optical system to act on a plasma formed by electrode breakdown of a gas, so as to maintain the plasma state and continuously emit broadband light.

[0003] Compared with a traditional broadband xenon lamp light source, the LSP light source has the advantages of high brightness, strong ultraviolet radiation, high stability and long service life, and is currently widely used in the fields of semiconductor thickness detection, medical treatment, material analysis and spectral detection.

[0004] However, with the iteration of technology, especially the continuous improvement of semiconductor process, the requirements for the brightness and ultraviolet intensity of the light source are increasing. Shorter wavelengths are beneficial to measuring thinner film layers, and brighter light sources can improve test efficiency. The brightness and ultraviolet intensity of the existing LSP light source have been difficult to meet the needs of advanced process technology. Therefore, further improving the brightness and ultraviolet intensity of the LSP light source has great significance to the field of semiconductor thickness detection.

[0005] It should be noted that the above content belongs to the technical cognition of the inventor and does not necessarily constitute the prior art. SUMMARY

[0006] In order to solve the above problems, the purpose of the present application is to provide a method and device for improving the brightness and ultraviolet intensity of a plasma light source, which introduces an independent plasma heating device (such as ohmic heating, RF heating, etc.) to work cooperatively with the main laser heating, realizes "active" compound heating of the plasma, and this cooperative effect can more effectively inject energy into the plasma, so that the core temperature and electron density are significantly improved, thereby greatly enhancing the total radiation brightness of the light source, especially the radiation intensity in the ultraviolet band. This method breaks through the bottleneck of single laser heating and can obtain higher light output efficiency under the same main laser power.

[0007] To achieve the above purpose, the present application provides a device for improving the brightness and ultraviolet intensity of a laser sustained plasma light source, which comprises a laser emitting device, an optical element device, a gas sealing device, a plasma heating device and a power supply device.

[0008] The laser emitting device is used for the main heating laser source, the optical element device is used for focusing the laser to the center of the plasma, and the gas sealing device is used for sealing the high-pressure gas.

[0009] The optical element device is located between the laser emitting device and the plasma.

[0010] Further, the plasma heating device is any one or more of an ohmic heating device, a radio frequency heating device, a laser heating device, and a magnetic field heating device.

[0011] The plasma heating device is embedded in the sidewall of the gas sealing device.

[0012] Further, the ohmic heating device comprises at least one pair of metal electrodes, the plasma is located between the two metal electrodes, the metal electrodes are symmetrically embedded in the sidewall of the gas sealing device, and are connected to the power supply device.

[0013] Further, the laser emitting device is any one or more of a semiconductor laser, a fiber laser, a solid-state laser, and a gas laser.

[0014] Further, the optical element device is any one or more of a lens, a mirror, and a dichroic mirror.

[0015] Further, the gas sealing device is any structural form and combination of a bulb, a metal-sealed chamber, and a glass-sealed chamber.

[0016] Further, the gas in the gas sealing device is one or more of helium, neon, argon, krypton, xenon, radon, and nitrogen.

[0017] Further, the configuration of the device includes a transmission type and a reflection type.

[0018] In the transmission type configuration, both the positive and negative poles of the power supply device are connected to radio frequency electrodes through wires, the two radio frequency electrodes are located on the two sides of the plasma, the axis of the metal electrodes is parallel to the incident laser beam and is located on the two sides of the plasma, the incident laser beam emitted by the laser emitting device is focused on the plasma after passing through the optical element device to heat the plasma, and finally the plasma heating device emits white light.

[0019] In the reflection type configuration, the optical element device is a dichroic mirror optical system, the optical element device is inclined relative to the laser emitting device, the device further comprises a mirror, the mirror is cup-shaped, the cup opening of the mirror faces the laser emitting device, the plasma heating device is located in the mirror, the power supply device is connected to a spiral coil through wires, the spiral coil is embedded in the inner wall of the mirror, the axis of the metal electrodes is perpendicular to the incident laser beam and is located on the two sides of the plasma, the incident laser beam emitted by the laser emitting device is focused on the plasma after passing through the optical element device and being reflected by the mirror to heat the plasma, and finally white light is emitted from one side of the optical element device; The spiral coil is located in the outer ring of the gas sealing device or is embedded in the gas sealing device.

[0020] Further, the insulation between the spiral coil and the gas sealing device is provided with a ceramic insulation sealing ring, and the internal part of the metal electrode is integrated with a liquid cooling channel A method for improving the brightness and ultraviolet intensity of a laser sustained plasma light source, applied to the device, the method is realized by actively heating the plasma, and the method comprises the following steps: S1, preparation before operation; Safety confirmation: Check whether all power supply connecting wires are intact and whether the grounding is reliable; Confirm that the gas sealing device has no visible cracks or damage; Wear necessary personal protective equipment; System check: Confirm that the laser emitting device, optical element device, plasma heating device and power supply device have been correctly installed in place; Check whether the liquid cooling system has been connected and filled with cooling liquid; According to the required spectral characteristics, select and fill the appropriate working gas.

[0021] S2, operation steps General steps: Gas filling and sealing: Fill the selected one or more mixed gases into the gas sealing device.

[0022] Accurately control the gas pressure in the chamber to the target range of 10-30 atm, close the gas valve, and ensure that the chamber is completely sealed; Start the cooling system: Turn on the liquid cooling channel in the metal electrode, set appropriate flow rate and temperature, and prepare for the subsequent heating process; Start the auxiliary plasma heating device: Turn on the power supply device and set it according to the heating method used: If it is an ohmic heating device: the power supply device supplies power to the metal electrode, sets the power output parameters: frequency is 10-100 kHz, voltage is 0.5-5 kV, generates initial discharge in the gas in the chamber through the metal electrode, and forms pre-ionized plasma; If it is an RF heating device: start the RF power supply and apply RF energy to the pre-ionization area through the RF antenna or electrode to preliminarily heat and maintain the plasma; Start the main laser heating: Turn on the laser emitting device; The laser beam is accurately focused to the center area of the plasma through the optical element device; The high-power main laser energy is strongly absorbed by the plasma, causing its temperature to rise sharply, forming a stable, high-brightness laser-sustained plasma. The auxiliary heating device works in conjunction with the main laser to jointly increase the density and temperature of the plasma. Light output and collection: The strongly heated plasma emits strong continuous spectrum, containing rich ultraviolet light, i.e., white light. Configuration-specific steps: Transmission configuration operation: Ensure that the device is in the transmission configuration: the axis of the metal electrode is parallel to the incident laser beam and is located on both sides of the plasma. After the incident laser beam passes through the optical element device and the plasma heating device, the white light generated is directly emitted from the other side of the device. The corresponding collection optical system is used on the opposite side to receive and utilize the emitted light. Reflection configuration operation: Ensure that the device is in the reflection configuration: the optical element device is a dichroic mirror optical system and is placed obliquely relative to the laser beam; the cup opening of the mirror is directly opposite the laser direction, and the plasma heating device is located inside; the axis of the metal electrode is perpendicular to the incident laser beam. The incident laser beam first strikes the dichroic mirror, which is highly transparent to the laser wavelength and reflects visible / ultraviolet light. The transmitted laser is reflected and focused by the cup-shaped mirror onto the plasma. The white light emitted by the plasma radiates in all directions, of which the light directed towards the cup-shaped mirror is collected and reflected back to the front of the plasma area, passing through the dichroic mirror again. At this time, the dichroic mirror reflects most of the visible light and ultraviolet light to the preset light path exit, thereby efficiently outputting the enhanced light beam.

[0023] S3, operation monitoring and optimization; Parameter monitoring and adjustment: Real-time monitoring of the stability, brightness, According to the needs, fine-tune the power of the main laser, the power of the auxiliary heating power supply, and the gas pressure in the chamber to optimize the overall brightness of the light source and the intensity of the ultraviolet band; Ensure that the cooling system continues to operate effectively.

[0024] S4, shutdown procedure Turn off the main laser: first turn off the laser output of the laser emission device; Turn off the auxiliary heating: then turn off the power supply device to stop the auxiliary heating of the plasma; Maintain cooling: after the main laser and auxiliary heating are turned off, keep the cooling system running for a period of time until all components are fully cooled to a safe temperature; Turning off the total power supply: finally, turn off the total power supply of the whole device.

[0025] The method and device for improving the brightness and ultraviolet intensity of a plasma light source can bring the following beneficial effects: 1. The device of the present application works cooperatively with the main laser heating by introducing an independent plasma heating device (such as ohmic heating, RF heating, etc.), which realizes the "active" compound heating of the plasma. This cooperative effect can more effectively inject energy into the plasma, significantly improve the core temperature and electron density, and thus greatly enhance the total radiation brightness of the light source, especially the radiation intensity in the ultraviolet band. This method breaks through the bottleneck of single laser heating and can obtain higher light output efficiency under the same main laser power. 2. The auxiliary heating device (such as ohmic heating electrode) in the device of the present application can pre-ionize the working gas before the main laser focuses, forming an initial plasma. This greatly reduces the energy threshold of the main laser for maintaining the plasma, making it easier and more reliable to ignite the plasma. At the same time, the continuous injection of auxiliary energy helps to maintain the stability of the plasma under fluctuating conditions, reducing the instability of the light source caused by plasma flickering or extinguishing.

[0026] 3. The liquid cooling channel integrated inside the spiral coil in the device of the present application can effectively remove a large amount of heat generated during the operation of the device, greatly relieving the thermal load and ablation problem of the electrode, and significantly prolonging the service life of the electrode and the entire device. 4. The ceramic insulating sealing ring provided between the spiral coil and the gas sealing device in the device of the present application not only ensures electrical insulation under high pressure, but also realizes reliable sealing of the cavity, ensuring long-term safe operation in a high-pressure gas environment. 5. The reflective configuration in the device of the present application ingeniously combines a cup-shaped reflector with a dichroic mirror optical system. The cup-shaped reflector can efficiently collect the light radiated to the side and back of the plasma and reflect it forward, while the dichroic mirror separates the main laser (high transmission) from the white light / ultraviolet light (high reflection) emitted by the plasma. This design greatly improves the collection and output efficiency of useful light (especially ultraviolet light), making the final light source output brightness higher. 6. The device of the present application provides two configurations: transmissive and reflective. Depending on different application scenarios and optical path requirements, the user can choose the appropriate configuration. At the same time, the plasma heating device supports multiple heating modes (ohmic, RF, laser, etc.), and the type and pressure of the working gas (10-30 atm) can also be flexibly adjusted according to the required spectral characteristics (such as selecting xenon gas to optimize ultraviolet output), giving the device wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 Schematic diagram of the transmission type configuration structure of the present application.

[0028] Figure 2 Schematic diagram of the reflection type configuration structure of the present application.

[0029] In the figure: 1, laser emitting device; 2, optical element device; 3, metal electrode; 5, power supply device; 6, gas sealing device; 9, white light; 10, reflecting mirror; 31, metal electrode; 32, plasma; 51, radio frequency electrode; 52, spiral coil. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail with reference to the accompanying drawings.

[0031] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0033] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected, or it can be communicated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of the present application, the description of the terms "one scheme", "some schemes", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the scheme or example are included in at least one scheme or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more schemes or examples.

[0035] Embodiments of the present application provide a device for improving the brightness and ultraviolet intensity of a laser sustained plasma light source, as shown in Figure 1 、 Figure 2 The device includes a laser emitting device 1, an optical element device 2, a gas sealing device 6, a plasma heating device 3 and a power supply device 5. The optical element device 2 is located between the laser emitting device 1 and the plasma 3, and the power supply device 5 is a radio frequency power supply.

[0036] The plasma heating device 3 is embedded in the side wall of the gas sealing device 6.

[0037] The plasma heating device 3 can be an ohmic heating device, a radio frequency (RF) heating device (such as an RF antenna / electrode and an RF power supply), a laser heating device (such as an additional laser and an optical system), etc.

[0038] The ohmic heating device includes at least one pair of metal electrodes 31, which are preferably copper electrodes. The plasma 32 is located between the two metal electrodes 31, which are symmetrically embedded in the side wall of the gas sealing device 6 and connected to the power supply device 5.

[0039] The laser emitting device 1 is used for main heating laser source, which can be a semiconductor laser, a fiber laser, a solid-state laser, a gas laser, etc.

[0040] The optical element device 2 is used for focusing laser to the center of the plasma 32, which can be a lens, a mirror (such as a glass mirror, a plastic lens, a metal mirror, etc.), a dichroic mirror, etc. optical elements or systems for shaping or focusing laser beams.

[0041] The gas sealing device 6 is used for sealing high-pressure gas, which can be a bulb, a metal sealing chamber, a glass sealing chamber, etc. structure for containing and sealing gas.

[0042] The gas in the gas sealing device 6 can be helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), nitrogen (N2), or any mixture of the above gases.

[0043] The gas sealing device 6 is a quartz light-transmitting chamber with a gas pressure of 10~30 atm.

[0044] The power supply unit 5 has an output frequency of 10–100 kHz and a voltage range of 0.5–5 kV.

[0045] The device can be configured as either a transmission type or a reflection type.

[0046] like Figure 1 As shown, in the transmission configuration, the positive and negative terminals of the power supply device 5 are connected to radio frequency electrodes 51 via wires. The two radio frequency electrodes 51 are located on both sides of the plasma 32. The incident laser beam emitted by the laser emitting device 1 passes through the optical element device 2 and is focused on the plasma 32 to heat it. Finally, the plasma heating device 3 emits white light 9.

[0047] like Figure 2 As shown, in the reflective configuration, the optical element device 2 is a dichroic mirror optical system. The optical element device 2 is tilted relative to the laser emitting device 1. The device also includes a reflector 10, which is cup-shaped. The mouth of the reflector 10 faces the laser emitting device 1. The plasma heating device 3 is located inside the reflector 10. The power supply device 5 is connected to a spiral coil 52 via wires. The spiral coil is embedded in the inner wall of the reflector 10. The incident laser beam emitted by the laser emitting device 1 passes through the optical element device 2 and is reflected and focused on the plasma 32 by the reflector 10 to heat it. Finally, white light 9 is emitted from one side of the optical element device 2.

[0048] A ceramic insulating sealing ring is provided at the insulation point between the spiral coil 52 and the gas sealing device 6. The spiral coil 52 has an integrated liquid cooling channel inside, which is used to cool the device during operation and extend the service life of the device.

[0049] The spiral coil 52 can be located on the outer ring of the gas sealing device 6 or embedded in the gas sealing device 6.

[0050] A method for improving the brightness and ultraviolet intensity of a laser-maintaining plasma source is applied to the above-mentioned device. The method is achieved by actively heating the plasma 32 and includes the following steps: S1, preparation before operation; Security Confirmation: Check that all power connection cables (laser emitter 1 and power supply 5) are intact and that the grounding is reliable.

[0051] Check the gas sealing device 6 (quartz chamber) for visible cracks or damages.

[0052] Wear necessary personal protective equipment, such as laser protective eyewear, UV-resistant gloves, etc.

[0053] System check: Verify that the laser emission device 1, optical element device 2, plasma heating device 3, power supply device 5, etc. are correctly installed and in place.

[0054] Check that the liquid cooling system is connected and filled with coolant, ensuring smooth circulation.

[0055] Select and fill the appropriate working gas (such as xenon Xe for high-intensity UV output) according to the required spectral characteristics (especially UV intensity).

[0056] S2, Operation steps General steps (applicable to both transmission and reflection configurations): Gas filling and sealing: Fill the gas sealing device 6 (quartz light-transmitting chamber) with one or more selected mixed gases (such as xenon).

[0057] Accurately control the gas pressure in the chamber to the target range of 10-30 atm. Close the gas valve to ensure the chamber is completely sealed.

[0058] Start the cooling system: Turn on the internal liquid cooling channel for the metal electrode 31, set appropriate flow rate and temperature, and prepare for subsequent heating process.

[0059] Start auxiliary plasma heating device 3: Turn on the power supply device 5 and set it according to the heating method used (ohmic heating, RF heating, etc.): If it is an ohmic heating device: the power supply device 5 supplies power to the metal electrode 31, sets the power output parameters: frequency 10-100 kHz, voltage 0.5-5 kV, generates initial discharge in the gas in the chamber through the metal electrode 31, and forms a pre-ionized plasma 32.

[0060] If it is an RF heating device: start the RF power supply and apply RF energy to the pre-ionization area through the RF antenna or electrode to preliminarily heat and maintain the plasma.

[0061] Start main laser heating: Turn on the laser emission device 1 (main heating laser source, such as fiber laser).

[0062] The laser beam is precisely focused to the central region of the plasma 32 by the optical element device 2 (lens or mirror system).

[0063] The high-power main laser energy is strongly absorbed by the plasma 32, causing its temperature to rise sharply, forming a stable, high-brightness laser-sustained plasma 32. The auxiliary heating device 3 works in conjunction with the main laser to jointly increase the density and temperature of the plasma 32.

[0064] Light output and collection: The strongly heated plasma 32 emits strong continuous spectrum, including abundant ultraviolet light, i.e., white light 9.

[0065] Configuration-specific steps: Transmission configuration operation: Ensure that the device is in the transmission configuration: the axis of the metal electrode 31 is parallel to the incident laser beam and is located on both sides of the plasma 32.

[0066] After the incident laser beam passes through the optical element device 2 and the plasma heating device 3 (and the plasma 32 therein), the white light 9 produced is directly emitted from the other side of the device.

[0067] The corresponding collection optical system is used on the opposite side to receive and utilize the emitted light.

[0068] Reflection configuration operation: Ensure that the device is in the reflection configuration: the optical element device 2 is a dichroic mirror optical system and is placed obliquely relative to the laser beam; the cup of the cup-shaped mirror 10 is directly opposite the laser direction, and the plasma heating device 3 is located inside; the axis of the metal electrode 31 is perpendicular to the incident laser beam.

[0069] The incident laser beam first strikes the dichroic mirror (optical element device 2), which is highly transparent to the laser wavelength and reflects visible / ultraviolet light.

[0070] The transmitted laser is reflected by the cup-shaped mirror 10 and converges on the plasma 32.

[0071] The white light 9 (including ultraviolet) emitted by the plasma radiates in all directions, of which the light directed towards the cup-shaped mirror 10 is collected and reflected back to the front of the plasma area, passing through the dichroic mirror again. At this time, the dichroic mirror reflects most of the visible light and ultraviolet light to the preset light path exit, thereby efficiently outputting the enhanced light beam.

[0072] S3, operation monitoring and optimization; Parameter monitoring and adjustment: Real-time monitoring of the stability and brightness of the plasma.

[0073] According to the needs, the power of the main laser, the power (voltage / frequency) of the auxiliary heating power supply (power supply device 5), and the pressure in the chamber are fine-tuned to optimize the overall brightness of the light source and the intensity of the ultraviolet band.

[0074] Ensure that the cooling system continues to function effectively and prevent overheating of the spiral coil 52 and the gas seal 6.

[0075] S4. Shutdown procedure Switch off the main laser: First, switch off the laser output of the laser emission device 1.

[0076] Switch off the auxiliary heating: Subsequently, switch off the power supply device 5 and stop the auxiliary heating of the plasma.

[0077] Maintain cooling: After the main laser and the auxiliary heating have been switched off, the cooling system is kept running for a certain period of time (e.g. 5-10 minutes) until all components (especially the metal electrode 3 and the gas seal 6) have cooled sufficiently to a safe temperature.

[0078] Switch off the total power supply: Finally, switch off the total power supply of the entire device.

[0079] The various embodiments described in this specification are intended to be exemplary only. The same parts of the various embodiments are mutually referred to, and each embodiment focuses on the differences with the other embodiments. In particular, the system embodiments are described relatively briefly, since they are substantially similar to the method embodiments, and the relevant parts are referred to the description of the method embodiments.

[0080] The above description is merely illustrative of the embodiments of the present application, and is not intended to limit the present application. The present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A device for enhancing the brightness and ultraviolet intensity of a laser-maintaining plasma light source, characterized in that, The device includes a laser emitting device (1), an optical element device (2), a gas sealing device (6), a plasma heating device (3), and a power supply device (5). The laser emitting device (1) is used as the main heating laser source, the optical element device (2) is used to focus the laser to the center of the plasma, and the gas sealing device (6) is used to seal the high-pressure gas; The optical element device (2) is located between the laser emitting device (1) and the plasma (3).

2. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 1, characterized in that, The plasma heating device (3) is any one or more of an ohmic heating device, a radio frequency (RF) heating device, and a laser heating device; The plasma heating device (3) is embedded in the side wall of the gas sealing device (6).

3. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 2, characterized in that, The ohmic heating device includes at least one pair of metal electrodes (31), plasma (32) is located between the two metal electrodes (31), the metal electrodes (31) are symmetrically embedded in the side wall of the gas sealing device (6) and connected to the power supply device (5).

4. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 3, characterized in that, The laser emitting device (1) is any one or more of a semiconductor laser, fiber laser, solid-state laser and gas laser.

5. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 4, characterized in that, The optical element device (2) is any one or more of a lens, a mirror, and a dichroic mirror.

6. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 5, characterized in that, The gas sealing device (6) can be any structural form or combination of a light bulb, a metal sealing chamber, and a glass sealing chamber.

7. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 6, characterized in that, The gas in the gas sealing device (6) is one or more of helium, neon, argon, krypton, xenon, radon, and nitrogen.

8. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 7, characterized in that, The device configuration includes both transmissive and reflective types; In the transmission configuration, the positive and negative poles of the power supply device (5) are connected to radio frequency electrodes (51) through wires. The two radio frequency electrodes (51) are located on both sides of the plasma. The incident laser beam emitted by the laser emitting device (1) passes through the optical element device (2) and is focused on the plasma (32) to heat it. Finally, the plasma heating device (3) emits white light (9). In the reflective configuration, the optical element device (2) is a dichroic mirror optical system. The optical element device (2) is tilted relative to the laser emitting device (1). The device also includes a reflector (10), which is cup-shaped. The mouth of the reflector (10) faces the laser emitting device (1). The plasma heating device (3) is located inside the reflector (10). The power supply device (5) is connected to a spiral coil (52) via wires. The spiral coil is embedded in the inner wall of the reflector (10). The incident laser beam emitted by the laser emitting device (1) passes through the optical element device (2) and is reflected and focused on the plasma (32) by the reflector (10) to heat it. Finally, white light (9) is emitted from one side of the optical element device (2). The spiral coil (52) is located on the outer ring of the gas sealing device (6) or embedded in the gas sealing device (6).

9. The device for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source according to claim 8, characterized in that, A ceramic insulating sealing ring is provided at the insulation between the spiral coil (52) and the gas sealing device (6), and a liquid cooling channel is integrated inside the spiral coil (52).

10. A method for improving the brightness and ultraviolet intensity of a laser-maintaining plasma light source, applied to the apparatus of claim 9, characterized in that, The method is achieved by actively heating plasma (32), and the method includes the following steps: S1. Preparations before operation; Security Confirmation: Check that all power cables are intact and that grounding is reliable; Confirm that the gas sealing device (6) has no visible cracks or damage; Wear the necessary personal protective equipment; System check: Confirm that the laser emitting device (1), optical component device (2), plasma heating device (3) and power supply device (5) are correctly installed and in place; Check that the liquid cooling system is connected and filled with coolant; Select and fill with the appropriate working gas according to the required spectral characteristics; S2, Operating Procedures General steps: Inflation and sealing: One or more selected mixed gases are introduced into the gas sealing device (6); Precisely control the air pressure in the chamber to the target range of 10~30 atm, close the air valve, and ensure that the chamber is completely sealed; Start the cooling system: Open the liquid cooling channel inside the metal electrode (31), set the preset flow rate and temperature, and prepare for the subsequent heating process; Start the auxiliary plasma heating device (3): Turn on the power supply (5) and set it according to the heating method used: If it is an ohmic heating device: the power supply device (5) supplies power to the metal electrode (31), and sets the power output parameters: frequency of 10–100kHz and voltage of 0.5–5 kV. The metal electrode (31) generates an initial discharge in the gas in the cavity to form a pre-ionized plasma (32). If it is an RF heating device: turn on the RF power supply, apply radio frequency energy to the pre-ionization region through the RF antenna or electrodes, and perform preliminary heating and maintenance of the plasma; Start main laser heating: Turn on the laser emitting device (1); The laser beam is precisely focused onto the central region of the plasma (32) through the optical element device (2); The high-power main laser energy is strongly absorbed by the plasma (32), causing its temperature to rise sharply, forming a stable, high-brightness laser to maintain the plasma (32). The auxiliary heating device (3) works in conjunction with the main laser to jointly increase the density and temperature of the plasma (32). Light output and collection: The intensely heated plasma (32) emits a strong continuous spectrum containing abundant ultraviolet light, i.e., white light (9). Configuration-specific steps: Transmission configuration operation: Ensure the device is in a transmission configuration: the axis of the metal electrode (31) is parallel to the incident laser beam and located on both sides of the plasma (32); After the incident laser beam passes through the optical element device (2) and the plasma heating device (3), the white light (9) generated is emitted directly from the other side of the device; The emitted light is received and utilized using a corresponding collecting optical system on the opposite side. Reflective configuration operations: Ensure the device is in a reflective configuration: the optical element device (2) is a dichroic mirror optical system and is placed at an angle relative to the laser beam; the cup of the reflector (10) faces the laser direction and the plasma heating device (3) is located inside it; the axis of the metal electrode (31) is perpendicular to the incident laser beam. The incident laser beam first illuminates a dichroic mirror, which has high transmittance for laser wavelengths and reflects visible / ultraviolet light; The transmitted laser light is reflected by the cup-shaped mirror (10) and focused onto the plasma (32); The white light (9) emitted by the plasma (including ultraviolet light) radiates in all directions. The light that hits the cup-shaped reflector (10) is collected and reflected back to the front of the plasma region, and then passes through the dichroic mirror again. At this time, the dichroic mirror reflects most of the visible light and ultraviolet light to the preset optical path exit, thereby efficiently outputting the enhanced beam. S3. Operation monitoring and optimization; Parameter monitoring and adjustment: Real-time monitoring of plasma stability, brightness, As needed, the power of the main laser, the power of the auxiliary heating power supply, and the air pressure in the cavity are finely adjusted to optimize the overall brightness of the light source and the intensity of the ultraviolet band. Ensure the cooling system operates continuously and effectively; S4, Power Off Procedure Turn off the main laser: First, turn off the laser output of the laser emitting device (1); Turn off auxiliary heating: Then turn off the power supply (5) to stop the auxiliary heating of the plasma; Maintaining Cooling: After the main laser and auxiliary heating are turned off, keep the cooling system running for a period of time until all components have cooled sufficiently to a safe temperature; Turn off the main power: Finally, turn off the main power supply for the entire device.

Images