Laser maintained plasma light source
By combining the resumption reflector and the conical uniform light rod, the problem of low coupling efficiency of the laser maintaining plasma light source when increasing the total output power is solved, and the light energy collection rate and light source stability are improved.
Patent Information
- Application Number
- CN202510439934.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-11
AI Technical Summary
While the existing laser maintains plasma light source increases the total light output power, the coupling efficiency has not been effectively improved, resulting in lower light source returns.
The resumption reflector is combined with a conical uniform light rod. The resumption reflector increases the light energy output through the reflective bowl and the resumption part. The incident end of the conical uniform light rod is large to improve the light energy collection rate. The pump laser resumption is reduced by setting an infrared absorption film on the edge of the reflector. The exit end of the conical uniform light rod ensures the uniform light irradiance uniformity.
While enhancing the light energy of small-numerical aperture, the coupling efficiency of plasma light sources is improved, the risk of laser damage is reduced, and the stability and durability of the light source are improved.
Smart Images
Figure CN120300577A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of optical devices, and particularly to a laser sustained plasma light source. Background Art
[0002] Laser sustained plasma (LSP) light source technology is a technology that generates a high-brightness light source through the interaction between a laser and a plasma. The plasma excited in high-pressure gas can be maintained under the action of a focused pump laser and emit broadband light. By changing parameters such as the power and divergence angle of the pump laser, the morphology and brightness of the plasma can be regulated. The light emitted by the plasma can be collected and modulated by a subsequent optical system for further utilization.
[0003] In a laser sustained plasma light source, the ratio of the output light power of the plasma light source to the light power effectively utilized by a subsequent optical system is the coupling efficiency of the plasma light source. A laser sustained plasma light source can increase the total output light power of the plasma light source by increasing the output light energy. However, while increasing the total output light power of the plasma light source, the coupling efficiency of the plasma light source has not been effectively improved, resulting in a low light source benefit of the plasma light source. The related prior art does not provide a technical solution that can simultaneously increase the total output light power and the coupling efficiency of the laser sustained plasma light source. Summary of the Invention
[0004] This application is made in view of the state of the above prior art. This application discloses a laser sustained plasma light source, which can increase the coupling efficiency of the plasma light source while increasing the output light energy with a small numerical aperture.
[0005] This application provides a laser sustained plasma light source, which includes a laser, a reflector, a dichroic mirror, a reflector, and a light homogenizing rod.
[0006] The laser is used to emit a pump laser, and the pump laser irradiates the reflector through the reflector and the dichroic mirror. The reflector is used to converge the pump laser to the plasma, and at least part of the broadband light emitted by the plasma can be homogenized by the light homogenizing rod and then emitted.
[0007] The reflector is a retroreflector, and the retroreflector includes a reflector bowl and a retroreflecting part. The inner surfaces of the reflector bowl and the retroreflecting part both form reflecting surfaces for reflecting light. The reflecting surface is a curved surface. The retroreflecting part is used to reflect at least part of the broadband light to increase the total output light power of the plasma light source.
[0008] The light homogenizing rod is a conical light homogenizing rod, and the area of the incident end of the conical light homogenizing rod is larger than the area of the emitting end of the conical light homogenizing rod, so as to improve the coupling efficiency of the plasma light source.
[0009] By cooperating the retroreflector with the conical light homogenizing rod, the plasma light source can enhance the light energy of the small numerical aperture while improving the coupling efficiency of the plasma light source. Among them, the retroreflector can increase the energy of the output light of the small numerical aperture, and the area of the incident end of the conical light homogenizing rod is relatively large, which can better receive the output light of the small numerical aperture with a larger focused spot, thereby improving the collection rate of the light energy gain of the small numerical aperture light, and can also ensure the uniformity of the light irradiance and the balance of the angular distribution at the emitting end of the light homogenizing rod.
[0010] In a possible implementation manner, the reflector is a multiple retroreflector, and the retroreflecting part of the multiple retroreflector includes a first retroreflecting part and a second retroreflecting part.
[0011] At least part of the inner surface of the first retroreflecting part forms a reflecting surface, and at least part of the inner surface of the second retroreflecting part forms a reflecting surface.
[0012] The multiple retroreflector can further increase the spatial collection rate of the light emitted by the plasma and the output power of the plasma light source.
[0013] In a possible implementation manner, the reflecting surface of the reflecting bowl has a first coating area and a second coating area.
[0014] The first coating area is provided with an infrared reflecting film, and the infrared reflecting film can reflect infrared light and is used to converge the pump laser to the plasma of the laser sustained plasma light source.
[0015] The second coating area is provided with an infrared absorbing film, and the infrared absorbing film can absorb infrared light and is used to reduce or avoid the pump laser from being retroreflected to the laser of the laser sustained plasma light source.
[0016] Both the infrared reflecting film and the infrared absorbing film can reflect visible light and / or ultraviolet light and are used to collect at least part of the broadband light emitted by the plasma.
[0017] By providing an infrared absorbing film in a part of the area of the reflector, the retroreflection of the pump laser by the reflector to the laser can be reduced or avoided, so as to reduce the risk of laser damage and improve the stability and durability of the laser sustained plasma light source.
[0018] In a possible implementation manner, the reflecting surface of the retroreflecting part of the retroreflector is entirely covered with the infrared absorbing film.
[0019] Retroreflectors can be used to increase the spatial collection rate of the light emitted by the plasma and the output power of the plasma light source. However, they also increase the pump laser power reflected back to the laser. Setting an infrared absorption film in the reflecting part can reduce the reflection of the pump laser.
[0020] In a possible implementation, the conical light homogenizing rod is a pyramid-shaped light homogenizing rod; alternatively, the conical light homogenizing rod is a conical light homogenizing rod.
[0021] The conical light homogenizing rod can be further limited to a pyramid-shaped or conical light homogenizing rod. Pyramid-shaped and conical light homogenizing rods are easy to fabricate and have good light homogenizing effects.
[0022] In a possible implementation, the infrared absorption film is disposed on the edge region of the inner surface of the reflecting bowl.
[0023] The edge region of the reflecting surface of the reflector is relatively likely to reflect the pump laser back to the laser. Setting the infrared absorption film in this region can enable the reflector to reduce or avoid reflecting the pump laser back to the laser while minimizing the impact on its ability to converge the pump laser.
[0024] In a possible implementation, the material of the light homogenizing rod is one of fused quartz, optical glass, and crystal materials.
[0025] The specific material of the light homogenizing rod is not limited. Here, preferred material selections suitable for the light homogenizing rod are given.
[0026] In a possible implementation, the reflecting surface of the reflector is one or a combination of a spherical surface, a non-spherical surface, and a freeform surface.
[0027] The specific shape of the reflecting surface of the reflector is not limited. Here, some preferred shapes of the reflecting surface suitable for the reflector are given.
[0028] In a possible implementation, it further includes a downstream optical device, and the downstream optical device includes one or more of a detector and a filter.
[0029] This laser sustained plasma light source can be applicable to various optical devices. The above content gives preferred selections of some downstream optical components suitable for the plasma light source.
[0030] In a possible implementation, it includes a plurality of the reflectors, and the plurality of reflectors can cooperate to output the broadband light emitted by the plasma.
[0031] The plasma light source can set a plurality of reflectors to form a cooperation, and more flexibly and efficiently output the broadband light emitted by the plasma. Description of the Drawings
[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0033] Figure 1 It is a schematic structural diagram of a laser sustained plasma light source with high coupling efficiency according to Embodiment 1 of the present application.
[0034] Figure 2 It is a schematic structural diagram of a laser sustained plasma light source with high coupling efficiency according to Embodiment 2 of the present application.
[0035] Figure 3 It is a schematic diagram of the optical path of the full numerical aperture according to an embodiment of the present application.
[0036] Figure 4 It is a schematic diagram of the optical path of the small numerical aperture according to an embodiment of the present application.
[0037] Figure 5 It is a schematic diagram of the optical path of a square light homogenizing rod known to the inventor.
[0038] Figure 6 It is a schematic diagram of the optical path of a conical light homogenizing rod according to an embodiment of the present application.
[0039] Figure 7 It is a schematic diagram of the optical path of the conical light homogenizing rod according to Embodiment 1 of the present application.
[0040] Figure 8 It is a schematic diagram of the radiation rate distribution of a retroreflector according to an embodiment of the present application.
[0041] Explanation of reference numerals
[0042] 10 - Laser;
[0043] 20 - Mirror;
[0044] 30 - Dichroic mirror;
[0045] 40 - Reflector;
[0046] 41 - Reflector bowl; 42 - Return part;
[0047] 421 - First return part; 422 - Second return part;
[0048] 50 - Light homogenizing rod;
[0049] 100 - Plasma. Detailed implementation manners
[0050] The exemplary implementation manners of the present application will be described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, rather than to exhaust all possible ways of the present application, nor to limit the scope of the present application.
[0051] A laser sustained plasma light source (LDLS) is a high-brightness broadband light source. It can use electrodes to generate nanosecond-level high-voltage pulses to excite the plasma, and then use continuous laser irradiation to maintain the plasma temperature, so that the plasma can continuously and stably radiate high-brightness spectra. The spectrum of this light source can cover ultraviolet, visible light, etc., and it is widely used as a light source for semiconductor devices. For example, it can be applied to semiconductor bright-field detection devices, etc.
[0052] Embodiment 1
[0053] Embodiment 1 of the present application provides a laser sustained plasma light source (hereinafter, sometimes simply referred to as "plasma light source"). As Figure 1 shown, the plasma light source may include a laser 10, a mirror 20, a dichroic mirror 30, a reflector 40, and a light homogenizing rod 50. The laser 10 can emit pump laser (mainly including infrared light), and the pump laser can irradiate the mirror 20, and the mirror 20 can reflect (refract) the pump laser. A dichroic mirror is also called a two-color mirror, which can selectively transmit or reflect light of a specific wavelength, that is, the dichroic mirror can almost completely transmit light of a certain wavelength, while almost completely reflecting light of other wavelengths. In the implementation manner of the present application, a dichroic mirror that can transmit infrared light and reflect ultraviolet light can be selected. The pump laser reflected by the mirror 20 can pass through the dichroic mirror 30 and then irradiate the reflector 40. The inner surface of the reflector can form a reflecting surface, and the reflecting surface can be a curved surface. The reflector 40 can reflect and converge the pump laser to the plasma 100, and the state of the plasma 100 can be maintained by the concentrated irradiation of the pump laser (infrared light). The plasma 100 can emit broadband light (especially including ultraviolet light). It can be understood that the plasma can emit broadband light to the outside world in all directions. Part of the broadband light can directly irradiate the dichroic mirror 30, and the broadband light (especially ultraviolet light) is irradiated to the light source outlet after being reflected by the dichroic mirror 30. Part of the broadband light can first irradiate the reflector 40, be irradiated to the dichroic mirror 30 after being reflected by the reflector 40 once, and then be reflected by the dichroic mirror 30 to the light source outlet. A light homogenizing rod, also called a light rod, a light tube, etc., can make an uneven light source uniform by using total internal reflection. The broadband light reaching the light source outlet can enter from the incident end of the light homogenizing rod 50 (exemplarily, Figure 1 and Figure 2The left side of the light homogenizing rod is its incident end, and the right side is its exit end) enters the light homogenizing rod 50. After multiple reflections of the broadband light within the light homogenizing rod 50, it can be homogenized and output from the exit end face of the light homogenizing rod 50. The homogenized broadband light output from the light homogenizing rod 50 can enter the downstream optical device for collection or utilization.
[0054] Furthermore, as Figure 1 shown, the reflector 40 in this embodiment can be a retroreflector, which can include a reflecting bowl 41 and a retroreflecting part 42. The retroreflecting part 42 can make the light irradiated onto the retroreflecting part 42 return along the original path (including approximately along the original path), and can be used to increase the utilization efficiency of the light emitted by the laser sustained plasma light source to the plasma (increase the spatial collection rate and the output power of the plasma light source). Specifically, as Figure 1 and Figure 3 shown, part of the light with a full numerical aperture emitted by the plasma can be reflected by the reflecting bowl 41 and then irradiated onto the dichroic mirror 30. As Figure 1 and Figure 4 shown, part of the light with a small numerical aperture emitted by the plasma can first be irradiated onto the retroreflecting part 42, and the retroreflecting part 42 reflects the light with a small numerical aperture to the reflecting bowl 41 and then irradiates it onto the dichroic mirror 30. That is, the light reflected by the retroreflecting part 42 of the retroreflector is mainly the light with a small numerical aperture output emitted by the plasma, enabling the retroreflector to increase the energy of the light with a small numerical aperture output. In an experimental example, as Figure 8 shown, under the action of the retroreflector, the energy of the output light with a small numerical aperture ( Figure 8 the band with a relatively high peak in
[0055] Although using a retroreflector in this laser sustained plasma light source can increase the energy of the output light with a small numerical aperture, the output light with a small numerical aperture still has problems such as a large focused spot and low coupling efficiency. To further improve the coupling efficiency, the light homogenizing rod 50 in the first embodiment of this example can adopt a conical light homogenizing rod with a larger area at the incident end and a smaller area at the exit end. As Figure 5 shown, it is the exit end optical path of the full numerical aperture light passing through a square light homogenizing rod under the condition of using an ordinary reflector (a reflector without a retroreflecting part). The area of the incident end of the traditional square light homogenizing rod is small, which is not conducive to collecting the relatively large light focus spot of the light with a small numerical aperture. As Figure 6 shown ( Figure 6 the exit end optical path of the square light homogenizing rod in Figure 5 is indicated by a dotted line, and the exit end optical path of the conical light homogenizing rod is indicated by a solid line), under the condition of using an ordinary reflector, the full numerical aperture light passing through the conical light homogenizing rod can increase the irradiance uniformity and angular distribution balance of the light at the exit end. As Figure 7 shown ( Figure 7 is indicated by a dashed line inFigure 6 The optical path of the full numerical aperture light rays (the optical path of the small numerical aperture light rays is schematically shown by solid lines). The area of the incident end of the conical light homogenizing rod is relatively large. In the case of arranging a retroreflector, it is more conducive to collecting the light energy gain of the small numerical aperture.
[0056] It can be understood that the size of the exit end of the light homogenizing rod 50 generally depends on the relevant parameter requirements of the optical device downstream of the light homogenizing rod. Therefore, it is difficult and costly to change the size of the exit end of the light homogenizing rod 50. By adopting a conical light homogenizing rod for this plasma light source, the coupling efficiency of this laser plasma light source can be improved without changing the size of the exit end of the light homogenizing rod.
[0057] Optionally, the conical light homogenizing rod 50 can be conical or pyramidal. It can be understood that the "conical shape and pyramidal shape" here can be approximate shapes. In practical applications, the exit end (with a relatively small area) of the conical light homogenizing rod can have a certain area. Therefore, the actual shape of the conical light homogenizing rod can also be close to a frustum of a cone or a frustum of a pyramid.
[0058] Optionally, the material of the light homogenizing rod 50 can be fused quartz, optical glass, crystal material, etc.
[0059] Preferably, in order for the reflector 40 to be able to reflect the infrared light emitted by the laser 10 and also be able to reflect the ultraviolet light emitted by the plasma, a film layer (i.e., an infrared reflection film) with a relatively high reflection ability for both infrared light and ultraviolet light can be formed on the inner surface (reflective surface) of the reflector 40. In some areas of the reflector 40 that are prone to causing the pump laser to retroreflect back to the laser (for example, the area near the edge of the reflecting bowl 41 of the reflector 40), a film layer (i.e., an infrared absorption film) with a relatively high reflection ability for ultraviolet light and a relatively high absorption ability for infrared light can be provided. That is, the reflector 40 can have a first coating area and a second coating area. The first coating area can be coated with an infrared reflection film, and the second coating area can be coated with an infrared absorption film. It can be understood that the main performance difference between the infrared reflection film and the infrared absorption film lies in their reflection / absorption ability for infrared light. Both the infrared reflection film and the infrared absorption film can have a relatively high reflection ability for ultraviolet light (allowing a certain degree of difference in their reflection ability for ultraviolet light).
[0060] Preferably, the infrared absorption film can be provided in the edge area of the inner surface of the reflecting bowl 41 of the reflector 40 (i.e., the bowl mouth area of the reflecting bowl 41).
[0061] Preferably, the infrared absorption film has an absorption rate greater than 80% (more preferably greater than 95%) in the infrared band (especially the band with a wavelength between 800 nm and 2000 nm) to ensure the effectiveness of its infrared light absorption. The infrared reflection film and the infrared absorption film have a reflectance greater than 90% in the ultraviolet band (especially the band with a wavelength between 200 nm and 400 nm).
[0062] Preferably, the film layer thickness of the infrared reflection film and the infrared absorption film can be 1-5 μm.
[0063] The reflector 40 can adopt a partitioned coating process to respectively form a first coating area and a second coating area on the inner surface of the reflector 40. The specific technical means of the partitioned coating process are not limited. For example, the partitioned coating process can be to respectively coat only one required film layer on different areas of the inner surface of the reflector 40 (that is, there is no mutual shielding or covering between different film layers). Or, the partitioned coating process can also be to coat one film layer on the entire inner surface of the reflector 40 and then coat another film layer on some areas (that is, it is allowed that there is shielding or covering between different film layers, and the absorption or reflection of infrared light in this area is determined by the film layer finally exposed on the upper layer). Preferably, a transition zone can also be formed in the adjacent areas of different film layers.
[0064] Optionally, the reflecting surface of the reflector 40 (including the reflecting surfaces of the reflecting bowl 41 and the restoring part 42) can be one or a combination of a spherical surface, a non-spherical surface (especially an elliptical surface, a parabolic surface), and a free surface.
[0065] Optionally, some laser sustained plasma light sources utilize the visible light band rather than the ultraviolet band emitted by the plasma. At this time, the ultraviolet light reflection function of the infrared reflection film and the infrared absorption film can be changed to a visible light reflection function or a function of simultaneously reflecting ultraviolet light and visible light. It can be understood that the performance of structures such as the dichroic mirror 30 can also be adaptively changed.
[0066] The plasma light source can also include a downstream optical device, which can collect and / or utilize the broadband light (especially ultraviolet light) at the output end of the aforementioned light homogenizing rod. The downstream optical device can be arranged downstream of the light homogenizing rod. Exemplarily, the downstream optical device can include optical devices such as a detector and a filter.
[0067] Optionally, the plasma light source can also include a plurality of the aforementioned reflectors 40, and the broadband light emitted by the plasma can be output through the mutual cooperation of the plurality of reflectors 40. The structures of the plurality of reflectors 40 can be the same, or the structures of the plurality of reflectors 40 can also be different.
[0068] Embodiment 2
[0069] Based on the above Embodiment 1, Embodiment 2 of the present application provides a laser sustained plasma light source. Components having the same or similar structures or functions as those in Embodiment 1 are labeled with the same reference numerals, and the detailed descriptions of these components are omitted.
[0070] As Figure 2 shown, the reflector 40 may also be a multiple retroreflector, which may include a reflector bowl 41 and a retroreflective portion 42. The retroreflective portion 42 may further include a first retroreflective portion 421 and a second retroreflective portion 422. The multiple retroreflector can further increase the light utilization efficiency of the laser sustained plasma light source, especially can further increase the output light energy of light with a small numerical aperture.
[0071] Preferably, at least part of the inner surface of the reflector bowl 41 of the multiple retroreflector and at least part of the inner surface of the retroreflective portion 42 (the side for reflecting ultraviolet light) are both provided with infrared absorption films (at least part of the inner surfaces of the first retroreflective portion 421 and the second retroreflective portion 422 of the retroreflective portion 42 of the multiple retroreflector may both be provided with infrared absorption films). The retroreflective portion 42 provided with the infrared absorption film can absorb the pump laser (infrared light) and mainly reflect the ultraviolet light formed by the plasma, especially reflect the light with a small numerical aperture in the ultraviolet light, reducing the damage risk of the laser 10.
[0072] Next, some beneficial effects of the embodiments of the present application will be briefly described.
[0073] The embodiments of the present application provide a laser sustained plasma light source, which uses a retroreflector and a conical light homogenizing rod in cooperation, so that the plasma light source can enhance the energy of light with a small numerical aperture while improving the coupling efficiency of the plasma light source. Among them, the retroreflective portion of the retroreflector can increase the energy of the output light with a small numerical aperture, and the area of the incident end of the conical light homogenizing rod is relatively large, which can better receive the output light with a small numerical aperture having a relatively large focused spot, thereby improving the collection rate of the light energy gain of the light with a small numerical aperture, and can also ensure the uniformity of the light irradiance and the angular distribution balance at the exit end of the light homogenizing rod.
[0074] It can be understood that in the present application, when the number of components or members is not particularly limited, the number may be one or more, and here "more than one" means two or more. For the case where the number of components or members shown in the drawings and / or described in the specification is a specific number such as two, three, four, etc., this specific number is usually exemplary rather than restrictive, and it can be understood as more than one, that is, two or more. However, this does not mean that the present application excludes the case of one.
[0075] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application. The above-mentioned preferred embodiments have further detailed the purpose, technical solution and advantages of the present invention. It should be understood that the above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A laser sustained plasma light source, characterized in that, It includes a laser (10), a reflector (20), a dichroic mirror (30), a reflector (40) and a light homogenizing rod (50). The laser (10) is used to emit pump laser, and the pump laser irradiates the reflector (40) via the reflector (20) and the dichroic mirror (30). The reflector (40) is used to converge the pump laser to the plasma, and at least part of the broadband light emitted by the plasma can be homogenized by the light homogenizing rod (50) and then emitted. The reflector (40) is a retroreflector, and the retroreflector includes a reflecting bowl (41) and a retroreflecting part (42). The inner surfaces of both the reflecting bowl (41) and the retroreflecting part (42) form reflecting surfaces for reflecting light. The reflecting surfaces are curved surfaces. The retroreflecting part (42) is used to reflect at least part of the broadband light to increase the total light output power of the plasma light source. The light homogenizing rod (50) is a conical light homogenizing rod, and the area of the incident end of the conical light homogenizing rod is larger than the area of the emitting end of the conical light homogenizing rod to improve the coupling efficiency of the plasma light source.
2. The laser sustained plasma light source according to claim 1, characterized in that, The reflector (40) is a multi-retroreflector, and the retroreflecting part (42) of the multi-retroreflector includes a first retroreflecting part (421) and a second retroreflecting part (422). At least part of the inner surface of the first retroreflecting part (421) forms a reflecting surface, and at least part of the inner surface of the second retroreflecting part (422) forms a reflecting surface.
3. The laser sustained plasma light source according to claim 1 or 2, characterized in that, The reflecting surface of the reflecting bowl (41) has a first coating area and a second coating area. The first coating area is provided with an infrared reflecting film, and the infrared reflecting film can reflect infrared light and is used to converge the pump laser to the plasma of the laser sustained plasma light source. The second coating area is provided with an infrared absorbing film, and the infrared absorbing film can absorb infrared light and is used to reduce or avoid the pump laser from retroreflecting to the laser of the laser sustained plasma light source. Both the infrared reflecting film and the infrared absorbing film can reflect visible light and / or ultraviolet light and are used to collect at least part of the broadband light emitted by the plasma.
4. The laser sustained plasma light source according to any one of claims 1 to 3, characterized in that, The reflecting surface of the retroreflecting part (42) of the retroreflector is entirely covered with the infrared absorbing film.
5. The laser sustained plasma light source according to any one of claims 1 to 4, characterized in that The conical light homogenizing rod is a pyramid-shaped light homogenizing rod; or, the conical light homogenizing rod is a conical light homogenizing rod.
6. The laser sustained plasma light source according to any one of claims 1 to 5, characterized in that, The infrared absorbing film is arranged in the edge area of the inner surface of the reflecting bowl (41).
7. The laser sustained plasma light source according to any one of claims 1 to 6, characterized in that The material of the light homogenizing rod (50) is one of fused quartz, optical glass and crystal material.
8. The laser sustained plasma light source according to any one of claims 1 to 7, characterized in that, The reflecting surface of the reflector (40) is one or a combination of a spherical surface, a non-spherical curved surface and a free-form surface.
9. The laser sustained plasma light source according to any one of claims 1 to 8, characterized in that, It further includes a downstream optical device, and the downstream optical device includes one or more of a detector, a filter, etc.
10. The laser sustained plasma light source according to any one of claims 1 to 9, characterized in that, It includes a plurality of the reflectors (40), and the plurality of reflectors (40) can cooperate to output the broadband light emitted by the plasma.