CN118017336A - MOPA laser device for inhibiting ASE and reflected light - Google Patents
MOPA laser device for inhibiting ASE and reflected light Download PDFInfo
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- CN118017336A CN118017336A CN202410146561.6A CN202410146561A CN118017336A CN 118017336 A CN118017336 A CN 118017336A CN 202410146561 A CN202410146561 A CN 202410146561A CN 118017336 A CN118017336 A CN 118017336A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
- H01S3/081—Construction or shape of optical resonators or components thereof comprising three or more reflectors
- H01S3/0813—Configuration of resonator
- H01S3/0815—Configuration of resonator having 3 reflectors, e.g. V-shaped resonators
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/09—Processes or apparatus for excitation, e.g. pumping
- H01S3/097—Processes or apparatus for excitation, e.g. pumping by gas discharge of a gas laser
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/10007—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating in optical amplifiers
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Abstract
The invention relates to the technical field of optics, in particular to a MOPA laser device for inhibiting ASE and reflected light. The device comprises an absorber, a seed light source, a first amplifier system, a second amplifier system, a first reflecting mirror, a lambda/4 phase delay reflecting mirror, a second reflecting mirror and tin drops which are sequentially arranged, wherein thin film polaroids are arranged in the first amplifier system and the second amplifier system; the reflection surface of the lambda/4 phase delay reflector forms an included angle of 45 degrees with the polarization direction of the incident light and is used for converting the linearly polarized light into a circularly polarized laser beam; the thin film polarizer is used to fully transmit P-polarized light and fully reflect S-polarized light. Under the condition of ensuring that the gain capability of the amplifier is not affected, ASE and reflected light in the MOPA laser system are effectively inhibited, and meanwhile, the stability of the MOPA system is ensured.
Description
Technical Field
The invention relates to the technical field of optics, in particular to a MOPA laser device for inhibiting ASE and reflected light.
Background
The invention relates to the technical field of extreme ultraviolet EUV lithography machine driving light sources, and provides a main oscillation power amplification MOPA (Master Oscillator Power Amplifier) laser device for inhibiting spontaneous radiation amplification ASE (Amplified Spontaneous Emission) and reflected light.
Currently, there are mainly four technical routes to EUV light sources: the only technical routes that can be used for mass production of chips are LPP-EUV (Laser Produced Plasma-Extreme Ultraviolet), i.e. extreme ultraviolet lithography of Laser plasma routes, are synchrotron radiation sources, discharge plasmas (DISCHARGED PRODUCED PLASMA, DPP), laser-assisted discharge plasmas (Laser-ASSISED DISCHARGE PLASMA, LDP), laser plasmas (Laser Produced Plasma, LPP). The driving laser used in the LPP-EUV technique is a high power, high repetition frequency short pulse CO 2 laser. However, the laser adopting the oscillator mode cannot meet the characteristics of high power, high repetition frequency and short pulse, and a technical route of Main Oscillation Power Amplification (MOPA) needs to be adopted, namely, the power of a high repetition frequency and short pulse seed source is amplified by using an Amplifier, so that high power, high repetition frequency and short pulse CO 2 laser is obtained. The fast axial flow CO 2 laser amplifier has the advantages of good beam quality, high conversion efficiency and more uniform gain distribution, so that the fast axial flow CO 2 laser amplifier is generally adopted for amplifying the short pulse CO 2 laser.
A large number of excited particles exist in the gain region of the fast axial flow CO 2 laser amplifier, and the gain region of a single amplifier is long, so that spontaneous emission amplified ASE is generated. ASE consumes the laser gain medium, reducing the energy level particle count on the laser, and thus affecting the extraction of the gain by the seed light. And ASE is generated not only in a single amplifier but also between the amplifiers connected in series in multiple stages. It is necessary to suppress ASE noise in MOPA laser systems. In addition, in the process of interaction between the laser output by the MOPA laser system and the substance, reflected light or stray light may be reflected from the surface of the substance and enter the MOPA laser system to generate parasitic oscillation, which may also cause gain reduction. The presence of ASE and reflected light not only causes a reduction in the gain capability of the amplifier, but may even cause damage to the amplifier and seed source, so that corresponding suppression measures for ASE and reflected light are necessary in MOPA laser systems.
The existing technical scheme for inhibiting ASE and various noise lights is mainly realized by adopting an isolator mode, the effect of inhibiting ASE is achieved by inserting the isolator between each stage of amplifiers, and the isolator can be placed between adjacent gas channels in the initial stage of amplifier design for ASE generated by a single amplifier so as to inhibit ASE generated by the single amplifier. In addition, a non-metallic absorbing material is coated in the amplifier discharge tube to form a noise light absorbing layer, so as to achieve the effect of suppressing various noise lights.
Because the gain length of the fast axial flow CO 2 laser amplifier of the Wanware level is long, the cost of the isolator and the nonmetallic absorption material adopted is high, the design of the amplifier is complex, and the stability of the whole light path can be influenced.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art, and provides a MOPA laser device for inhibiting ASE and reflected light, which effectively inhibits ASE and reflected light in a MOPA laser system and ensures the stability of the MOPA system under the condition that the gain capacity of an amplifier is not affected.
The invention relates to a MOPA laser device for inhibiting ASE and reflected light, which comprises an absorber, a seed light source, a first amplifier system, a second amplifier system, a first reflecting mirror, a lambda/4 phase delay reflecting mirror, a second reflecting mirror and tin drops, wherein the first amplifier system, the second amplifier system, the first reflecting mirror, the lambda/4 phase delay reflecting mirror, the second reflecting mirror and the tin drops are sequentially arranged;
the seed light source is used for providing signal light for the laser system;
The first amplifier system and the second amplifier system are used for amplifying the power of the seed light source and preventing ASE caused by window reflection self-excitation;
The reflection surface of the lambda/4 phase delay reflector forms an included angle of 45 degrees with the polarization direction of incident light and is used for converting linearly polarized light into circularly polarized laser beams;
the first reflecting mirror is arranged on the laser transmission light path and is used for converting P polarized light into 45-degree polarized light;
the second reflecting mirror is used for turning and acting the laser on the tin drop which falls vertically;
The tin drop is used for generating plasma through interaction with high-power short-pulse CO 2 laser so as to radiate extreme ultraviolet EUV light;
The absorber is used for absorbing S polarized light reflected by the surface of the film polaroid;
the film polarizer is used for completely transmitting P polarized light and completely reflecting S polarized light.
Preferably, an isolator is arranged between the first amplifier system and the second amplifier system.
More preferably, the first amplifier system includes a first amplifier, and a first thin film polarizer and a second thin film polarizer symmetrically disposed at two ends of the first amplifier, where the first thin film polarizer, the second thin film polarizer and the optical axis form brewster angles.
More preferably, the second amplifier system includes a second amplifier and a third thin film polarizer and a fourth thin film polarizer symmetrically disposed at two ends of the second amplifier, and the third thin film polarizer and the fourth thin film polarizer form brewster angles with the optical axis.
Preferably, the seed light source adopts linearly polarized light.
Preferably, the amplifiers adopted in the first amplifier system and the second amplifier system are radio frequency excited fast axial flow CO 2 laser amplifiers.
Preferably, the absorber is a water-cooled metal body with a laser high-absorption material plated on the surface.
More preferably, the separator is an SF 6 saturated absorbent separator.
Preferably, the absorber is disposed below the fourth thin film polarizer and on the reflection light path of the fourth thin film polarizer.
Preferably, the device further comprises a focusing mirror positioned between the tin drop and the second reflecting mirror, wherein the focusing mirror is used for focusing laser to the surface of the tin drop; the CO 2 laser light output by the seed light source sequentially passes through the first amplifier system, the isolator, the second amplifier system, the first reflecting mirror, the lambda/4 phase delay reflecting mirror, the second reflecting mirror and the focusing mirror, then reflected light is generated on the surface of the tin drop, returns along the original light path, sequentially passes through the focusing mirror, the second reflecting mirror, the lambda/4 phase delay reflecting mirror, the first reflecting mirror and the thin film polaroid of the second amplifier system, and then is absorbed by the absorber.
The beneficial effects of the invention are as follows:
1. Based on the existing isolation technology, a combined structure form of a film polaroid TFP and a reflection lambda/4 phase delay reflector RPR is adopted. The invention can effectively eliminate ASE and reflected light of the MOPA laser system, prevent ASE generated by the amplifier from reducing the output power of the amplifier, prevent the reflected light from affecting the amplifier and the seed light source (inhibit the reflected light generated on the surface of a tin drop, ensure the stability of the MOPA system) by utilizing the combined structure of the film polarizer and the lambda/4 phase delay reflector, and improve the stability and the safety of the MOPA laser system. And on the premise of effectively improving the ASE inhibiting capability, the complexity and the cost of the system are reduced. The 45-degree linearly polarized light is changed into circularly polarized light after passing through the lambda/4 phase delay reflector RPR, and the effect is more uniform in all directions of the substance relative to the linearly polarized light.
2. The two ends of each amplifier are provided with the thin film polaroid so as to effectively inhibit ASE in a single amplifier; and secondly, an isolator is arranged between the amplifiers to inhibit ASE of the multi-amplifier series connection.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention;
FIG. 2 is a schematic diagram of the TFP principle of the film polarizer of the present invention;
FIG. 3 is a schematic diagram of the RPR principle of the reflective lambda/4 phase retardation mirror of the present invention;
FIG. 4 is a schematic diagram of the correspondence between the optical paths and the polarization states according to the present invention.
In the figure: 1. seed light source, 2, first amplifier system, 201, first thin film polarizer, 202, first amplifier, 203, second thin film polarizer, 3, second amplifier system, 301, third thin film polarizer, 302, second amplifier, 303, fourth thin film polarizer, 4, isolator, 5, first mirror, 6, lambda/4 phase retardation mirror, 7, second mirror, 8, tin drop, 9, absorber, 10, focusing mirror.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise. "plurality" means "two or more".
Example 1
Fig. 1 shows a schematic structural diagram of a MOPA laser device for suppressing ASE and reflected light according to a preferred embodiment of the present application (fig. 1 shows a first embodiment of the present application), and for convenience of explanation, only the portions related to this embodiment are shown, and the details are as follows:
The purpose of the axial fast flow CO 2 laser amplifier design is to amplify the laser power of the seed light source 1, so that in order to enable the seed light source to extract the gain of the amplifier more, it is necessary to prevent the consumption of the reverse population density in the amplifier by various other noise light, which mainly includes spontaneous emission amplified ASE and reflected light. ASE is generated mainly due to the presence of a large number of excited state particles in the amplifier and the excessively long gain length of the amplifier itself. The presence of ASE not only affects the extraction of the gain by the seed light, but also causes damage to the seed light source by the laser output by the amplifier. The reflected light generated at the surface of the droplet during interaction with a substance such as droplet 8 from the laser output by the MOPA system can be adversely affected by the return of the reflected light into the MOPA system along the original optical path.
Based on the above-described problems, the present invention proposes a MOPA laser device that suppresses ASE and reflected light, and hereinafter, the present invention will be further described with reference to the accompanying drawings. Note that the same modules are denoted by different reference numerals. But their names and functions are the same. Such as the first to fourth thin film polarizers, are all thin film polarizer TFPs. Therefore, the description is not repeated.
The MOPA laser device for inhibiting ASE and reflected light comprises an absorber 9, a seed light source 1, a first amplifier system 2, a second amplifier system 3, a first reflecting mirror 5, a lambda/4 phase delay reflecting mirror 6, a second reflecting mirror 7 and tin drops 8 which are sequentially arranged, wherein thin film polarizers are arranged in the first amplifier system 2 and the second amplifier system 3;
the seed light source 1 is used for providing signal light for a laser system;
The first amplifier system 2 and the second amplifier system 3 are used for amplifying the power of the seed light source 1 and preventing ASE caused by window reflection self-excitation;
The reflecting surface of the lambda/4 phase delay reflecting mirror 6 forms an included angle of 45 degrees with the polarization direction of the incident light and is used for converting the linearly polarized light into a circularly polarized laser beam;
the first reflecting mirror 5 is arranged on the laser transmission light path and is used for converting P polarized light into 45-degree polarized light;
The second reflecting mirror 7 is used for turning and acting the laser on the tin drop 8 which falls vertically;
The tin drop 8 is used for generating plasma through interaction with high-power short-pulse CO 2 laser so as to radiate extreme ultraviolet EUV light;
the absorber 9 is used for absorbing S polarized light reflected by the surface of the film polarizer;
The focusing mirror 10 is used for focusing laser light to the surface of the tin drop;
The thin film polarizer is used to fully transmit P-polarized light and fully reflect S-polarized light.
In one embodiment, an isolator 4 is provided between the first amplifier system 2 and the second amplifier system 3.
In one embodiment, the first amplifier system 2 includes a first amplifier 202, and a first thin film polarizer 201 and a second thin film polarizer 203 symmetrically disposed at both ends of the first amplifier 202, where the first thin film polarizer 201 and the second thin film polarizer 203 form brewster angles with the optical axis.
In one embodiment, the second amplifier system 3 includes a second amplifier 302 and a third thin film polarizer 301 and a fourth thin film polarizer 303 symmetrically disposed at both ends of the second amplifier 302, the third thin film polarizer 301 and the fourth thin film polarizer 303 having brewster's angle with the optical axis.
In one embodiment, a focusing mirror 10 is further provided between the tin droplet 8 and the second mirror 7 for focusing the laser light onto the surface of the tin droplet 8.
In one embodiment, the seed light source 1 employs linearly polarized light.
In one embodiment, the amplifiers employed in the first and second amplifier systems 2, 3 are radio frequency excited fast axial flow CO 2 laser amplifiers.
In one embodiment, the absorber 9 is a water-cooled metal body with a surface coated with a laser super-absorbing material.
In one embodiment, the separator 4 is an SF 6 saturable absorber separator.
In one embodiment, absorber 9 is disposed below fourth film polarizer 303 and on the reflected light path of fourth film polarizer 303.
In one embodiment, the CO 2 laser output by the seed light source 1 sequentially passes through the first amplifier system 2, the isolator 4, the second amplifier system 3, the first reflecting mirror 5, the lambda/4 phase delay reflecting mirror 6, the second reflecting mirror 7 and the focusing mirror 10, then generates reflected light on the surface of the tin droplet 8, and the reflected light returns along the original optical path and is absorbed by the absorber 9 after sequentially passing through the focusing mirror 10, the second reflecting mirror 7, the lambda/4 phase delay reflecting mirror 6, the first reflecting mirror 5 and the thin film polarizer 303 of the second amplifier system 3.
The seed light source 1 is a signal light source and is used for providing signal light for the MOPA laser system. Specifically, the seed light is CO 2 laser light having a wavelength of 10.6 μm, and the seed light outputs P-polarized light parallel to the incident surface. The seed light passes through the first thin film polarizer 201 and enters the first amplifier 202.
The principle of the thin film polarizer is shown in fig. 2, and the TFP is composed of a coated plate, which forms the brewster angle with the incident beam. The thin film coating can enhance reflectivity for S-polarized light while maintaining high transmittance for P-polarized components.
The first amplifier 202 and the second amplifier 302 are used to generate gain, which amplifies the power of the incident laser light. It should be noted that the present invention uses a fast axial flow CO 2 laser amplifier excited by radio frequency, and because of its complex structure, fig. 1 only represents the main cavity of the amplifier, and other auxiliary systems are not shown, such as: the laser radio frequency power supply and matching network, control system, water cooling system, gas mixing unit, etc.
In order to restrain ASE noise light in the MOPA laser system, thin film polaroids are added at the inlet and outlet positions of each stage of amplifier, which is equivalent to using the thin film polaroids with large angle bias as windows of the amplifier, and ASE caused by reflection self-excitation of the amplifier windows can be effectively prevented through the arrangement.
In order to further suppress ASE of the multi-stage amplifier series, an isolator 4 is provided between the first amplifier system 2 and the second amplifier system 3. Specifically, the separator may be an SF 6 saturated absorbing separator, a faraday separator, or a polarization separator. The SF 6 saturated absorption optical isolator has the characteristic of high damage threshold, so that the isolator becomes the isolator most commonly used for the 10.6 mu m CO 2 laser amplifier.
By adding thin film polarizers at both ends of the first amplifier 202 and the second amplifier 302 and inserting the isolator 4 between the amplifier systems, ASE inside the single amplifier and between the multi-stage amplifiers is effectively suppressed.
The first reflecting mirror 5 is disposed on an optical path for transmitting laser light, and is used for changing the transmission direction of the laser light, and the P polarized light becomes 45 ° polarized light after passing through the first reflecting mirror 5.
Fig. 3 is a schematic diagram of the principle of the lambda/4 phase retardation mirror RPR, in which when a linearly polarized light beam with a polarization direction of 45 ° with respect to the reflection surface passes through a mirror with a lambda/4 phase retardation reflection film coated on the surface, the linear polarization of the CO 2 laser beam can be converted into a circularly polarized laser beam. The circularly polarized light after passing the second mirror 7 is incident on the target tin droplet 8 and generates plasma to radiate EUV light for lithography, a process of interaction of laser light and a substance is not described in detail here.
The following describes the operation and design principle of suppressing reflected light:
first, the reflected light generated on the surface of the tin droplet 8 returns along the original optical path, becomes circularly polarized light with the opposite rotation direction, passes through the second reflecting mirror 7, and then becomes vertical 45-degree linear polarized light after being reflected by the lambda/4 phase retardation reflecting mirror RPR. Then, the light becomes S-polarized light of the normal incidence plane after passing through the first reflecting mirror 5. Finally, since the thin film polarizer TFP can totally reflect S polarized light, it is reflected into the absorber 9 after passing through the thin film polarizer 303. Therefore, the reflected light after the reflection of the tin droplet cannot enter the MOPA system, thereby suppressing the influence of the reflected light on the system.
According to the above light path design, the transmission route and polarization state of the seed light are as follows:
seed light travel route: seed light source 1→first amplifier system 2→isolator 4→second amplifier system 3→first mirror 5→lambda/4 phase delay mirror 6→second mirror 7→focusing mirror 10→tin droplet 8.
Reflected light generated after acting on the tin droplet 8- & gt focusing mirror 10- & gt second mirror 7- & gt lambda/4 phase retardation mirror 10- & gt first mirror 5- & gt fourth thin film polarizer 303- & gt absorber 9.
Laser polarization state change: p-polarized light, 45-polarized light, circularly polarized light with opposite rotation, vertically 45-polarized light, and S-polarized light.
The specific correspondence between the optical paths and the polarization states is shown in fig. 4.
In general, the invention firstly sets the thin film polaroid at two ends of each amplifier so as to effectively inhibit ASE in a single amplifier; secondly, an isolator is arranged between the amplifiers to inhibit ASE of the serial connection of the multiple amplifiers; finally, the combined structure of the thin film polarizer TFP and the reflective lambda/4 phase delay reflector RPR is utilized to inhibit the reflected light generated on the surface of the tin drop, so that the stability of the MOPA system is ensured. And the linear polarized light at 45 degrees can be changed into circular polarized light by utilizing the lambda/4 phase delay reflector RPR, so that the effect is more uniform in all directions of the substance relative to the linear polarized light.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (10)
1. A MOPA laser device for suppressing ASE and reflected light, characterized by: the device comprises an absorber (9), a seed light source (1), a first amplifier system (2), a second amplifier system (3), a first reflecting mirror (5), a lambda/4 phase delay reflecting mirror (6), a second reflecting mirror (7) and tin drops (8) which are sequentially arranged, wherein thin film polaroids are arranged in the first amplifier system (2) and the second amplifier system (3);
The seed light source (1) is used for providing signal light for the laser system;
The first amplifier system (2) and the second amplifier system (3) are used for amplifying the power of the seed light source (1) and preventing ASE caused by window reflection self-excitation;
The reflection surface of the lambda/4 phase delay reflector (6) forms an included angle of 45 degrees with the polarization direction of incident light, and is used for converting linearly polarized light into circularly polarized laser beams;
The first reflecting mirror (5) is arranged on the laser transmission light path and is used for converting P polarized light into 45-degree polarized light;
the second reflecting mirror (7) is used for turning and acting laser on a tin drop (8) which falls vertically;
The tin drop (8) is used for generating plasma through interaction with high-power short-pulse CO 2 laser so as to radiate extreme ultraviolet EUV light;
The absorber (9) is used for absorbing S polarized light reflected by the surface of the film polaroid;
the film polarizer is used for completely transmitting P polarized light and completely reflecting S polarized light.
2. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: an isolator (4) is arranged between the first amplifier system (2) and the second amplifier system (3).
3. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the first amplifier system (2) comprises a first amplifier (202), and a first thin film polaroid (201) and a second thin film polaroid (203) which are symmetrically arranged at two ends of the first amplifier (202), wherein the first thin film polaroid (201), the second thin film polaroid (203) and an optical axis form Brewster angles.
4. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the second amplifier system (3) comprises a second amplifier (302) and a third thin film polaroid (301) and a fourth thin film polaroid (303) which are symmetrically arranged at two ends of the second amplifier (302), wherein the third thin film polaroid (301) and the fourth thin film polaroid (303) form Brewster angles with an optical axis.
5. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the seed light source (1) adopts linearly polarized light.
6. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the amplifiers adopted in the first amplifier system (2) and the second amplifier system (3) are radio frequency excited axial fast flow CO 2 laser amplifiers.
7. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the absorber (9) is a water-cooled metal body with the surface plated with a laser high-absorption material.
8. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 1, wherein: the isolator (4) is an SF 6 saturable absorption isolator.
9. The MOPA laser apparatus for suppressing ASE and reflected light as defined in claim 4, wherein: the absorber (9) is disposed below the fourth thin film polarizer (303) and on the reflection light path of the fourth thin film polarizer (303).
10. The MOPA laser apparatus for suppressing ASE and reflected light as claimed in claim 2, wherein: the device further comprises a focusing mirror (10) positioned between the tin drop (8) and the second reflecting mirror (7), wherein the focusing mirror (10) is used for focusing laser to the surface of the tin drop (8);
CO 2 laser output by the seed light source (1) sequentially passes through the first amplifier system (2), the isolator (4), the second amplifier system (3), the first reflecting mirror (5), the lambda/4 phase delay reflecting mirror (6), the second reflecting mirror (7) and the focusing mirror (10), then reflected light is generated on the surface of the tin drop (8), returns along an original light path, sequentially passes through the focusing mirror (10), the second reflecting mirror (7), the lambda/4 phase delay reflecting mirror (6), the first reflecting mirror (5) and the thin film polaroid (303) of the second amplifier system (3), and then is absorbed by the absorber (9).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410146561.6A CN118017336A (en) | 2024-02-02 | 2024-02-02 | MOPA laser device for inhibiting ASE and reflected light |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410146561.6A CN118017336A (en) | 2024-02-02 | 2024-02-02 | MOPA laser device for inhibiting ASE and reflected light |
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| Publication Number | Publication Date |
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| CN118017336A true CN118017336A (en) | 2024-05-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202410146561.6A Pending CN118017336A (en) | 2024-02-02 | 2024-02-02 | MOPA laser device for inhibiting ASE and reflected light |
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| Country | Link |
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| CN (1) | CN118017336A (en) |
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