Optical path tuning device and method

Abstract

The present invention discloses an optical path tuning device and method, which relate to the field of laser technology, and are used to adjust the optical path of a ring cavity under low error conditions, thereby ensuring that the laser quality meets the requirements. In the device, when the light output module is in the light output mode, it is located in the transmission optical path of the amplifying cavity, and is used to output the amplified seed light to the optical measurement unit; the optical measurement unit is used to measure the optical information of the amplified seed light and send it to the control device; the control device is used to determine that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters based on the received optical information, and tune the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters. The method is performed using the device proposed in the above technical solution. The optical path tuning device provided by the present invention is used in laser optical path tuning.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to an optical path tuning device and method. Background Art

[0002] As the lithography node is about to enter the 32nm node, ArF excimer lithography has become the mainstream and is expected to be applied to the lower 22nm node and 16nm node. As the lithography node is reduced, the ring cavity technology can be used to ensure that the ArF excimer laser has a more stable narrow spectral line width, greater output power, higher dose stability and longer gas life. It can be seen that the accurate control of the laser beam passing through the gain region of the amplifying cavity determines the success or failure of the ring cavity technology.

[0003] In the prior art, the optical path of the excimer laser is long, the degree of modularization is high, and the coupling degree of each link is reduced, which makes it difficult to adjust the optical path transmission of the ring cavity. Although the laser guidance method has been introduced to debug the optical path transmission of the ring cavity, it is difficult for operators to control the various errors therein and the expected effect cannot be achieved. Summary of the invention

[0004] The object of the present invention is to provide an optical path tuning device and method, so as to adjust the optical path of a ring cavity with relatively low error, thereby ensuring that the laser quality meets the requirements.

[0005] In order to achieve the above-mentioned object, the present invention provides an optical path tuning device, which is applied to a laser transmission system having an amplifying cavity and at least one level of adjustable reflector, wherein each level of the adjustable reflector is used to reflect incident seed light to the amplifying cavity to generate corresponding amplified seed light; the optical path tuning device comprises: a light output module, an optical measurement unit, and a control device communicating with the optical measurement unit;

[0006] When the light output module is in the light output mode, the light output module is located in the transmission optical path of the amplifying cavity, and is used to output the amplified seed light emitted by the amplifying cavity to the optical measurement unit; the optical measurement unit is used to measure the optical information of the amplified seed light and send the optical information to the control device;

[0007] The control device is used to receive the optical information sent by the optical measurement unit, and when it is determined according to the optical information that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters, tune the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters.

[0008] Compared with the prior art, in the optical path tuning device provided by the present invention, when the light output module is in the light output mode, the light output module is located in the transmission optical path of the amplifying cavity, so that the light output module can output the amplified seed light emitted from the amplifying cavity to the optical measurement unit, thereby ensuring that the optical measurement unit can measure the optical information of the amplified seed light. At the same time, since the control device communicates with the optical measurement unit, the control device can receive the optical information sent by the optical measurement unit. Therefore, when the control device determines that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters according to the optical information sent by the optical measurement unit, the attitude angle of the adjustable reflector corresponding to the amplified seed light can be tuned according to the characteristic parameters of the amplified seed light and the preset characteristic parameters. After that. After the adjustable reflector reflects the corresponding incident seed light to the amplifying cavity, the optical information of the corresponding amplified seed light emitted from the amplifying cavity meets the preset characteristic parameters. It can be seen that the optical path tuning device provided by the present invention uses the debugging of the adjustable reflector as an aid, and focuses on the characteristic parameters of the amplified seed light, so that when the characteristic parameters of the amplified seed light determined by the optical information of the amplified seed light do not meet the preset characteristic parameters, the attitude angle of the corresponding adjustable reflector is adjusted according to the characteristic parameters of the amplified seed light and the preset characteristic parameters, thereby ensuring that the output light energy value and beam quality passing through the laser transmission system meet user requirements. In addition, by using the light output module to output the amplified seed light out of the laser transmission system, and directly using the optical measurement unit to measure the light, it is also possible to avoid the error caused by using the auxiliary visible laser to guide the optical path to debug the optical path, and reduce the error of the optical element caused.

[0009] The present invention also provides an optical path tuning method, which is applied to an optical path tuning system having a laser transmission system and an optical path tuning device; the laser transmission system comprises an amplifying cavity and at least one level of adjustable reflector, each level of the adjustable reflector is used to provide incident seed light for generating corresponding amplified seed light to the amplifying cavity; the optical path tuning device comprises a light output module, an optical measurement unit and a control device; the optical path tuning method comprises:

[0010] When the light output module is in the light output mode, the light output module outputs the amplified seed light emitted from the amplifying cavity to the optical measurement unit; the optical measurement unit measures the optical information of the amplified seed light and sends the optical information to the control device;

[0011] The control device receives the optical information sent by the optical measurement unit, and when it is determined according to the optical information that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters, tunes the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters.

[0012] Compared with the prior art, the beneficial effects of the optical path tuning method provided by the present invention are the same as the beneficial effects of the optical path tuning device described in the above technical solution, which will not be described in detail here.

[0013] The present invention also provides an optical path tuning system, comprising: a laser transmission system and at least one optical path tuning device described in the above technical solution; the laser transmission system comprises an amplifying cavity and at least one level of adjustable reflector, and each level of the adjustable reflector is used to provide incident seed light to the amplifying cavity to generate corresponding amplified seed light.

[0014] Compared with the prior art, the beneficial effects of the optical path tuning system provided by the present invention are the same as the beneficial effects of the optical path tuning device described in the above technical solution, which will not be described in detail here.

[0015] The present invention also provides an excimer laser device, comprising the optical path tuning device described in the above technical solution, wherein the light output module included in the optical path tuning device is located in the housing of the excimer laser.

[0016] Compared with the prior art, the beneficial effects of the excimer laser device provided by the present invention are the same as the beneficial effects of the optical path tuning device described in the above technical solution, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of an excimer laser device with a ring cavity structure in the related art;

[0019] Figure 2 A schematic diagram of the structure of an optical path tuning system provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the structure of an optical path tuning device provided in an embodiment of the present invention;

[0021] Figure 4 It is a structural schematic diagram of the spot size in an embodiment of the present invention;

[0022] Figure 5 A flow chart of an optical path tuning method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0026] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Figure 1 The schematic diagram of the structure of the excimer laser device with a ring cavity structure in the related art is shown as an example. Figure 1 As shown, the excimer laser device includes a master oscillator MO, a linear narrowing module LNM, a partial reflector PR, a line width analysis module LAM, a master oscillator wavefront engineering box MO WEB and a laser transmission system 100. The laser transmission system 100 may include an amplifying cavity PA (such as a power amplifying cavity), a first-stage adjustable reflector R1, a second-stage adjustable reflector R2, and the like.

[0029] like Figure 1As shown, the master oscillator MO generates a small energy narrow linewidth laser pulse as a seed light S0 by means of a linear narrowing module LNM. After the seed light passes through a partial reflector PR and a linewidth analysis module LAM, it is refracted by the master oscillator wavefront engineering box MOWEB, and then the seed light S0 is reflected to the amplifying cavity PA by the first-stage adjustable reflector R1 for primary amplification. The generated primary amplified seed light S1 is emitted from the amplifying cavity PA, and the primary amplified seed light S1 is reflected by the second-stage adjustable reflector R2, and the primary amplified seed light S1 is reflected to the amplifying cavity PA for secondary amplification. The generated secondary amplified seed light S2 is output from the amplifying cavity PA. Here, the first-stage adjustable reflector R1 and the second-stage adjustable reflector R2 can be high reflectors. The first-stage adjustable reflector R1 includes a first adjustable reflector, and the second-stage adjustable reflector R2 includes a second adjustable reflector and a third adjustable reflector.

[0030] In practical applications, such as Figure 1 As shown, the angle α between the primary amplified seed light S1 and the secondary amplified seed light S2 in the discharge cavity can be controlled within a certain range, such as α≤8mrad, by optical path design, so that the two beams are basically parallel to the electrode of the amplifying cavity PA. For example: the primary amplified seed light S1 passes through the center of the electrode, and the secondary amplified seed light S2 is parallel to the electrode, passes through the amplifying cavity PA, and enters the next module.

[0031] In the related technology, the ring cavity technology is used to make the seed light generated by the main oscillator cavity pass through the gain amplifier cavity back and forth, prolonging the residence time in the discharge cavity, and the amplifier cavity operates in a deep saturation state. Compared with the single-pass amplification technology, the advantages of this method are mainly reflected in: higher efficiency, greater energy, more stable output, and wider output pulses. In order to ensure the effectiveness of the ring cavity technology, it is necessary to accurately control the light path through the gain region of the amplifier cavity. However, existing gas laser devices such as excimer laser devices are large in size, have long optical paths, and are highly modularized, so that the coupling degree of the functional links of the excimer laser device is not high, resulting in the difficulty of adjusting the laser transmission optical path of the excimer laser device.

[0032] At present, the conventional optical path tuning method is to use auxiliary visible laser to guide the optical path debugging. However, due to the dispersion of optical materials with different wavelengths, there is still a certain error in laser transmission after debugging the optical path with auxiliary visible laser. In addition, in this process, it is difficult for general operators to control the error amount caused by multiple optical components, and the expected effect cannot be achieved.

[0033] The embodiment of the present invention provides an optical path tuning system, which can tune the optical path with a small error so that the energy and beam quality of the laser meet the requirements.

[0034] Figure 2 The structural schematic diagram of the optical path tuning system provided by the embodiment of the present invention is illustrated. Figure 2 As shown, the optical path tuning system provided by the embodiment of the present invention includes: a laser transmission system 100 and at least one optical path tuning device 200. The laser transmission system 100 includes an amplifying cavity PA and at least one level of adjustable reflector, and each level of adjustable reflector is used to reflect the incident seed light to the amplifying cavity PA to generate the corresponding amplified seed light. The optical path tuning device 200 here can be one or more. When there is one optical path tuning device 200, the adjustable reflectors of each level can share one optical path tuning device 200 in a time-sharing manner. The optical path tuning device 200 can measure the optical information after the amplified seed light is transferred out, and determine the characteristic parameters of the amplified seed light according to the optical information. When the preset characteristic parameters are not met, the corresponding adjustable reflector of the amplified seed light is adjusted, thereby avoiding the errors and operational inconveniences caused by the use of visible light laser guidance.

[0035] In practical applications, each stage of the adjustable reflector is used to reflect the incident seed light to the amplifying cavity. The amplifying cavity is used to emit a corresponding amplified seed light according to the incident seed light. For example: Figure 2 As shown, the at least one-stage adjustable reflector includes a first-stage adjustable reflector R1 and a second-stage adjustable reflector R2. The amplifying cavity PA has a first light-transmitting end T1 and a second light-transmitting end T2. The first-stage adjustable reflector R1 is close to the first light-transmitting end T1, and the second-stage adjustable reflector R2 is close to the second light-transmitting end T2. At this time, the first-stage adjustable reflector R1 is used to reflect the seed light S0 as the incident seed light to the amplifying cavity PA, so that the amplifying cavity PA emits a first amplified seed light S1; the second-stage adjustable reflector R2 is used to receive the first amplified seed light S1 emitted by the amplifying cavity PA, and reflect the first amplified seed S1 light as the incident seed light to the amplifying cavity PA, so that the amplifying cavity PA emits a second amplified seed light S2.

[0036] An optical path tuning device provided in an embodiment of the present invention is applied to a laser transmission system having an amplifying cavity and at least one adjustable reflector. The structure of the laser transmission system can be referred to Figure 2 The relevant description is not repeated here.

[0037] Figure 3 The following is a schematic diagram of the structure of an optical path tuning device provided by an embodiment of the present invention. Figure 3 As shown, the optical path tuning device provided by the embodiment of the present invention includes: a light output module 210 , an optical measurement unit 220 , and a control device 230 communicating with the optical measurement unit 220 .

[0038] like Figure 2 and Figure 3As shown, when the light output module 210 is in the light output mode, the light output module 210 is located in the transmission optical path of the amplifying cavity PA, and is used to output the amplified seed light SX emitted from the amplifying cavity PA to the optical measurement unit 220. The optical measurement unit 220 is used to measure the optical information of the amplified seed light SX and send the optical information to the control device 230. In addition, the position of the light output module 210 can be set according to the level of the adjustable reflector R corresponding to the amplified seed light SX to be measured. For example: when the light output module 210 is in the light output mode, the optical measurement unit 220 needs to be located on the light output optical path of the light output module 210 to ensure that after the light output module 210 outputs the amplified seed light SX emitted from the amplifying cavity PA, the optical measurement unit 220 can collect the optical information of the amplified seed light SX.

[0039] by Figure 2 Taking the two-stage adjustable reflector shown as an example, when the optical measurement unit 220 needs to measure the optical information of the once-amplified seed light S1, the light transfer module 210 can be set between the second light-transmitting end T2 of the amplifying cavity PA and the second-stage adjustable reflector R2, so that the light transfer module 210 transfers the once-amplified seed light S1 to the optical measurement unit 220; when it is necessary to measure the optical information of the secondary-amplified seed light S2, the light transfer module 210 can be close to the first light-transmitting end T1 of the amplifying cavity PA, so that the light transfer module 210 transfers the secondary-amplified seed light S2 to the optical measurement unit 220.

[0040] like Figure 2 As shown, when the light output module 210 is in idle mode, the light output module 210 can be located in an area outside the transmission optical path of the amplifying cavity PA. If the light output module 210 is integrated in the optical path tuning device 200, the light output module 210 can be moved out of the transmission optical path of the amplifying cavity PA by electrical control after the optical path tuning, so as to avoid affecting the normal transmission of the laser. If the light output mode is not integrated in the optical path tuning device 200, the light output module 210 can be taken out of the laser transmission system after the optical path tuning, so as to avoid affecting the normal transmission of the laser. It can be seen that when the light output module 210 is in idle mode and light output mode, the area where it is located is different. Based on this, an intelligent control method can be adopted to control the position of the light output module 210. Exemplarily, the control device 230 communicates with the light output module 210, so that the control device 230 can be used to control the light output module 210 to switch between the idle mode and the light output mode.

[0041] like Figure 2 and Figure 3As shown, in order to intelligently control the environment in which the light output module 210 is located, the above-mentioned optical path tuning device 200 may also include an image sensor, which communicates with the control device 230. The image sensor may be arranged on the light output module 210 to collect the environment in which the light output module 210 is located. When the light output module 210 needs to be in the light output mode, it is possible to determine whether the environment in which the light output module 210 is located is converted to the transmission optical path of the amplifying cavity PA through the image transmitted by the image sensor. When the light output module 210 needs to be in the idle mode, it is possible to determine whether the environment in which the light output module 210 is located is converted outside the transmission optical path of the amplifying cavity PA through the image transmitted by the image sensor.

[0042] like Figure 2 As shown, for the above-mentioned light output module 210, it can be a movable reflective element. For example, the movable reflective element includes a driving mechanism and a reflective element arranged on the driving mechanism. When the control device 230 is connected to the driving mechanism for communication, the control device 230 can control the driving mechanism to drive the reflective element to achieve the conversion between the idle mode and the light output mode.

[0043] In one example, the driving mechanism may be a linear driving mechanism, including but not limited to a screw-nut mechanism or a linear guide mechanism. Figure 2 Arrow A or arrow B) in the figure can push the output reflector forward and out of the optical path. When the light output module 210 is not needed, the control device 230 can control the driving mechanism to withdraw the reflective element from the optical path of the amplified seed light SX to ensure that the optical path of the amplified seed light SX is unobstructed.

[0044] For example, when the driving mechanism is a lead screw nut mechanism, the lead screw nut mechanism can be an electric lead screw nut mechanism, and the control device can control the rotation direction of the motor of the electric lead screw nut mechanism so that the nut can move linearly in two opposite directions along the lead screw, thereby realizing the conversion between the idle mode and the light output mode.

[0045] like Figure 3 As shown, for the above optical measurement unit 220, it can include an imaging lens 221 and a light detector 222. The imaging lens 221 is arranged on the detection surface of the light detector 222. The light detector 222 communicates with the control device 230. The light detector 222 is one of a pyroelectric detector and a magneto-optical effect sensor. The pyroelectric detector is a common test instrument in the laboratory, which is convenient for employees to operate and use proficiently.

[0046] In specific implementation, Figure 3As shown, the imaging lens 221 can image the amplified seed light SX, and the amplified seed light SX is collected by the light detector 222. The light detector 222 converts the collected light signal into an electrical signal and transmits it to the control device 230.

[0047] In one example, if Figure 3 As shown, when the light output module 210 is in the light output mode, the light output module 210 is located in the depth of field range of the imaging lens 221 to ensure that the image obtained by the imaging lens 221 is clear. The imaging lens 221 can be a double telecentric lens, but is not limited thereto, as long as it is ensured that when the light output module 210 is in the light output mode, the light output module 210 is located in the depth of field range of the imaging lens 221.

[0048] For example, if Figure 3 As shown, when the light output module 210 is a movable reflective element. When the movable reflective element includes a driving mechanism and a reflective element disposed on the driving mechanism, the light output module 210 is located within the depth of field of the imaging lens 221, which can weaken the length effect of the reflective element along the light output direction of the amplified seed light SX. In other words, when the light output module 210 is located within the depth of field of the imaging lens 221, the mechanical positioning difficulty of the light output module 210 is relatively low, and it is not necessary to strictly reach the preset position, as long as the light output module 210 is ensured to be located on the optical path of the amplified seed light SX.

[0049] For example, Figure 3 As shown, P represents the intersection of the amplified seed light SX on the reflection surface M, N represents the light incident surface of the imaging lens 221, L is the distance between point P and surface N, and ΔL represents the length of the reflection surface along the outgoing direction of the amplified seed light SX (the propagation direction of the outgoing light SZ). When the length range shown by ΔL is within the depth of field D of the imaging lens 221, the imaging lens 221 can capture a clear image.

[0050] like Figure 3 As shown, when the imaging lens 221 can be a double telecentric lens. The double telecentric lens can eliminate the measurement error caused by the inaccurate position of the object plane and the image plane, and reduce the measurement error. It can be seen that the optical path tuning device 200 provided in the embodiment of the present invention can eliminate the error caused by mechanical processing by selecting the depth of field and type of the optical lens, reduce the difficulty of operation, save adjustment time, and is easy for machine operators to accept.

[0051] like Figure 3As shown, in order to integrate some units of the optical path tuning device 200 into the laser transmission system, the optical path tuning device 200 also includes a light-transmitting window 240 for integration into the laser transmission system. The light-transmitting window 240 is located between the light output module 210 and the optical measurement unit 220. The light-transmitting window 240 has a light-transmitting lens, and the light-transmitting lens may have an anti-reflection film to reduce light loss. In this case, the light output module 210 can be located in the laser transmission system, so that the user can perform optical path tuning without opening the cover of the laser transmission system. This approach does not destroy the dynamic seal of the machine, reduces the pollution of the external environment to the optical components in the optical path transmission, and delays the service life of the components.

[0052] like Figure 2 and Figure 3 As shown, for the above-mentioned control device 230, it is used to receive the optical information sent by the optical measurement unit 220, and it may have a display interface or may not have a display interface. When the control device 230 has a display interface. The control device 230 can display the received optical information and display the characteristic parameters of the amplified seed light SX, which helps the user to understand the problems of the machine in real time. On this basis, the control device 230 is also used to determine that the characteristic parameters of the amplified seed light SX do not meet the preset characteristic parameters according to the optical information, and tune the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters.

[0053] The above-mentioned preset characteristic parameters can be determined according to the optical information of the laser that meets the requirements of beam energy and quality. For example: optical design and actual debugging tests can be carried out in the early stage to determine that the spot size of the light beam that meets the requirements of beam energy and beam quality after amplification in the gain zone is the preset characteristic parameter. After receiving the optical information sent by the optical unit, the control device 230 can determine the spot size of the amplified seed light SX according to the optical information. When the spot size of the amplified seed light SX does not meet the spot size defined as the preset characteristic parameter, it can be considered that the spot size of the adjustable reflector R corresponding to the amplified seed light SX needs to be tuned. It can be seen that when the characteristic parameter of the amplified seed light SX in the embodiment of the present invention is the spot size of the amplified seed light SX, the preset characteristic parameter is the preset spot size. The preset spot size meets the spot size of the amplified seed light SX of the output light energy of the laser transmission system.

[0054] For example, when the spot of the amplified seed light SX is a rectangular spot, the preset characteristic parameter includes a preset length threshold and a preset width threshold of the rectangular spot. The preset length threshold can be a fixed value or a range value. Similarly, the preset width threshold can be a fixed value or a range value.

[0055] When the preset length threshold is a range value, the maximum value of the preset length threshold is X0+0.5mm. The minimum value of the preset length threshold is X0-0.5mm, and the maximum value of the preset width threshold is Y0+0.2mm. The minimum value of the preset length threshold is Y0-0.2mm. On this basis, Figure 4 The schematic diagram of the spot size of the amplified seed light in the embodiment of the present invention is illustrated. Figure 3 and Figure 4 As shown, when the control device 230 determines that the rectangular spot length of the amplified seed light SX is X and the length is Y, it can be determined whether X is in the range of X0-0.5mm to X0+0.5mm and whether Y is in the range of Y0-0.2mm to Y0+0.2mm. When X is in the range of X0-0.5mm to X0+0.5mm and Y is in the range of Y0-0.2mm to Y0+0.2mm, it means that the rectangular spot size of the amplified seed light SX meets the preset spot size, that is, the characteristic parameters of the amplified seed light SX meet the preset characteristic parameters, and there is no need to tune the adjustable reflector R corresponding to the amplified seed light SX. When X is not in the range of X0-0.5mm to X0+0.5mm, or Y is not in the range of Y0-0.2mm to Y0+0.2mm, or X is not in the range of X0-0.5mm to X0+0.5mm, and Y is not in the range of Y0-0.2mm to Y0+0.2mm, it means that the rectangular spot size of the amplified seed light SX meets the preset spot size, that is, the characteristic parameters of the amplified seed light SX meet the preset characteristic parameters, and the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX needs to be tuned. The attitude angle of the adjustable reflector R can be a pitch angle or other propagation direction that can achieve light direction adjustment.

[0056] In an alternative approach, Figure 3 As shown, the control device 230 is used to intermittently tune the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters. This adjustment method can effectively alleviate the error caused by the attitude angle of the adjustable reflector R being out of sync with the optical information, and prevent the problem of over-adjustment or under-adjustment caused by one-time adjustment. For example: the control device 230 can automatically adjust the knob to turn 1 / 4 turn clockwise or counterclockwise and pause for 30 seconds. At this time, the optical information measured by the optical measurement unit 220 is stable, and a second adjustment can be made.

[0057] like Figure 2 and Figure 3As shown, when at least one adjustable reflector R includes a first-stage adjustable reflector R1 and a second-stage adjustable reflector R2, when the second-stage adjustable reflector R2 includes multiple second-stage adjustable reflectors, considering that in actual applications, the second-stage adjustable reflector R2 cannot be adjusted at a large angle, the above-mentioned control device 230 is also used to determine that the attitude angles of each second-stage adjustable reflector have been adjusted. If the characteristic parameters of the secondary amplified seed light S2 do not meet the preset characteristic parameters, the attitude angle of the first-stage adjustable reflector R1 is updated when the characteristic parameters of the primary amplified seed light S1 meet the preset characteristic parameters.

[0058] In practical applications, such as Figure 2 As shown, when the second-stage adjustable reflector R2 contains two adjustable reflectors, the attitude angle of the first-stage adjustable reflector R1 can be tuned first, and then the attitude angle of the second-stage adjustable reflector R2 can be tuned. When all the second-stage adjustable reflectors R2 contained in the second-stage adjustable reflector R2 are adjusted, and the requirements are still not met (such as the spot size cannot meet the preset spot size), the attitude angle of the first-stage adjustable reflector R1 is adjusted, and the spot size corresponding to the first-stage adjustable reflector R1 is ensured to reach the preset spot size, thereby simplifying the difficulty of optical path tuning.

[0059] From the above, it can be seen that Figure 2 and Figure 3As shown, in the optical path tuning device 200 provided by the embodiment of the present invention, when the light output module 210 is in the light output mode, the light output module 210 is located in the transmission optical path of the amplifying cavity PA, so that the light output module 210 can output the amplified seed light SX emitted by the amplifying cavity PA to the optical measuring unit 220, thereby ensuring that the optical measuring unit 220 can measure the optical information of the amplified seed light SX. At the same time, since the control device 230 communicates with the optical measuring unit 220, the control device 230 can receive the optical information sent by the optical measuring unit 220. Therefore, when the control device 230 determines that the characteristic parameters of the amplified seed light SX do not meet the preset characteristic parameters according to the optical information sent by the optical measuring unit 220, the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX can be tuned according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters. After that. After the adjustable reflector R reflects the corresponding incident seed light to the amplifying cavity PA, the optical information of the corresponding amplified seed light SX emitted from the amplifying cavity PA meets the preset characteristic parameters. It can be seen that the optical path tuning device 200 provided in the embodiment of the present invention uses the debugging of the adjustable reflector R as an aid, and focuses on the characteristic parameters of the amplified seed light SX, so that when the characteristic parameters of the amplified seed light SX determined by the optical information of the amplified seed light SX do not meet the preset characteristic parameters, the attitude angle of the corresponding adjustable reflector R is adjusted according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters, thereby ensuring that the output light energy value and beam quality passing through the laser transmission system meet user requirements. In addition, the optical path tuning device 200 provided in the embodiment of the present invention uses the light output module 210 to output the amplified seed light SX out of the laser transmission system, and directly uses the optical measurement unit 220 to measure the light, which not only avoids the error caused by using the auxiliary visible laser to guide the optical path to debug the optical path, but also reduces the error of the optical element caused.

[0060] The embodiment of the present invention further provides an optical path tuning method, which is applied to an optical path tuning system having a laser transmission system and an optical path tuning device 200. The laser transmission system includes an amplifying cavity PA and at least one level of adjustable reflector R, each level of adjustable reflector R is used to reflect incident seed light to the amplifying cavity PA to generate corresponding amplified seed light SX. The optical path tuning device 200 has a light output module 210, an optical measurement unit 220 and a control device 230.

[0061] Figure 5 The flowchart of the optical path tuning method provided by the embodiment of the present invention is illustrated. Figure 5 As shown, the optical path tuning method provided by the embodiment of the present invention includes:

[0062] Step 100: When the light output module 210 is in the light output mode, the light output module 210 outputs the amplified seed light SX emitted by the amplifying cavity PA to the optical measurement unit 220. It can be understood that before the light output module 210 is in the light output mode, the light output module 210 is in the idle mode, and the control device 230 can control the light output module 210 to switch from the idle mode to the light output mode.

[0063] Step 200: The optical measurement unit 220 measures the optical information of the amplified seed light SX. In practical applications, when the optical measurement unit 220 includes a light detector 222 and an imaging lens 221 disposed on the detection surface of the light detector 222, the imaging lens 221 can collect the amplified seed light SX outputted by the light output module 210, and the formed light spot image is detected by the light detector 222 to obtain the light spot of the amplified seed light SX.

[0064] Step 300: The optical measurement unit 220 sends optical information to the control device 230. The optical information here may be a photoelectric signal.

[0065] Step 400 : the control device 230 receives the optical information sent by the optical measurement unit 220 .

[0066] Step 500: When the control device 230 determines according to the optical information that the characteristic parameters of the amplified seed light SX do not meet the preset characteristic parameters, the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX is tuned according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters.

[0067] In practical applications, such as Figure 3 As shown, the control device 230 can intermittently tune the attitude angle of the adjustable reflector R corresponding to the amplified seed light SX according to the characteristic parameters of the amplified seed light SX and the preset characteristic parameters, so as to avoid the problem of asynchronous adjustment of the attitude angle of the optical information and the adjustable reflector R, thereby accurately adjusting the attitude angle of the adjustable reflector R.

[0068] like Figure 3 As shown, the characteristic parameter of the amplified seed light SX can be the spot size of the amplified seed light SX, and the preset characteristic parameter is the preset spot size, which satisfies the spot size of the amplified seed light SX of the output light energy of the laser transmission system. For example: when the adjustable reflector R is a rotatable high reflector, the control device 230 can determine the pitch angle adjustment amount of the high reflector according to the difference between the spot size of the amplified seed light SX and the preset spot size. Then, the pitch angle of the high reflector corresponding to the amplified seed light SX is adjusted according to the adjustment information of the attitude angle.

[0069] like Figure 4As shown, the light spot of the above-mentioned amplified seed light SX is a rectangular light spot, and the preset characteristic parameters include a preset length threshold and a preset width threshold of the rectangular light spot. The maximum value of the preset length threshold is X0+0.5mm, and the minimum value of the preset length threshold is X0-0.5mm; the maximum value of the preset width threshold is Y0+0.2mm, and the minimum value of the preset length threshold is Y0-0.2mm.

[0070] like Figure 2 As shown, when at least one level of adjustable reflector R includes a first level adjustable reflector R1 and a second level adjustable reflector R2, the first level adjustable reflector R1 is used to reflect the seed light as incident seed light to the amplifying cavity PA, so that the amplifying cavity PA emits a first amplified seed light S1, and the second level adjustable reflector R2 is used to receive the first amplified seed light S1 emitted by the amplifying cavity PA, and reflect the first amplified seed light S1 as incident seed light to the amplifying cavity PA, so that the amplifying cavity PA emits a second amplified seed light S2. The second level adjustable reflector R2 includes a plurality of second level adjustable reflectors R2. After step 400, the above optical path tuning method may further include the following steps:

[0071] Step 600: When the control device 230 determines that the attitude angles of all second-stage adjustable reflectors have been adjusted, if the characteristic parameters of the secondary amplified seed light S2 do not meet the preset characteristic parameters, and if the characteristic parameters of the primary amplified seed light S1 meet the preset characteristic parameters, the attitude angles of the first-stage adjustable reflectors are updated.

[0072] In order to clearly describe the optical path tuning method of the optical path tuning device 200 provided in the embodiment of the present invention, Figure 2 Taking the laser transmission system shown in as an example, the optical path tuning method of the laser transmission system is described in detail. It should be understood that Figure 3 As shown, the imaging lens 221 contained in the optical measurement unit 220 of the optical path tuning device 200 can be a bi-telecentric lens, and the light detector 222 can be a pyroelectric light detector. The first-stage adjustable reflector R1 contained in the laser transmission system is defined as a first tunable reflector. The second-stage adjustable reflector R2 is defined as an adjustable reflector composed of a second tunable reflector and a third tunable reflector.

[0073] In the first step, the light output module 210 is rotated into the optical path of the primary amplified seed light S1 (i.e., between the second light-transmitting end T2 of the amplifying cavity PA and the second-stage adjustable reflector R2), and the imaging lens 221 is installed on the detection surface of the light detector 222.

[0074] In practical applications, a linear guide mechanism or a screw nut mechanism can be used to screw the reflective element along the direction indicated by the first arrow A into between the second light-transmitting end T2 of the amplifying cavity PA and the second-stage adjustable reflective element R2.

[0075] The second step is to open the control device 230, which may be a computer device with a display interface, and the computer device may have image processing software installed therein. When the control device 230 is opened, the image processing software has been opened and can process image information. The computer device may include but is not limited to a mobile phone, a desktop computer or a tablet computer.

[0076] In the third step, when the primary amplified seed light S1 is emitted from the amplifying cavity PA, the primary amplified seed light S1 is turned out by a reflecting element to form a primary turned-out light SZ1, so that the primary turned-out light SZ1 is received by the imaging lens 221, thereby ensuring that the light detector 222 detects the light spot of the primary amplified seed light S1.

[0077] In the fourth step, the control device 230 can measure the spot length X1 and spot width Y1 of the once-enlarged seed light S1 using the image processing software therein. For the preset characteristic parameters of the enlarged seed light, it can include a preset length threshold and a preset width threshold. And, depending on the level of the adjustable reflector, the corresponding preset characteristic parameters of the enlarged seed light are different. Based on this, for the preset characteristic parameters of the once-enlarged seed light S1, its preset length threshold can be X 01 -0.5mm to X 01 +0.5mm, the preset width threshold can be Y 01 -0.2mm to Y 01 +0.2mm. When X1 is at X 01 -0.5mm to X 01 +0.5mm, Y1 is located at Y 01 -0.2mm to Y 01 +0.2mm, it is determined that the spot size of the first amplified seed light S1 meets the preset spot size of the first amplified seed light S1, and the fifth step is executed. If any one of the spot length X1 and the spot width Y1 does not meet the preset characteristic parameters of the first amplified seed light S1, the control device 230 can adjust the pitch angle of the first tunable reflector until both the spot length X1 and the spot width Y1 meet the requirements to execute the fifth step. It should be understood that

[0078] In practical applications, when adjusting the pitch angle of the first tunable reflector, the first tunable reflector can be adjusted intermittently. For example, when the pitch angle of the first tunable reflector is controlled by a knob, the knob can be controlled to rotate a certain angle along the direction of arrow C1, and then paused, and then the next rotation is performed after the image size is stable, so as to avoid adjustment errors caused by the asynchronous movement of the spot image and the adjustment knob.

[0079] Step 5: When the spot size of the first amplified seed light S1 meets the preset spot size of the first amplified seed light S1, rotate the light output module 210 out of the optical path of the first amplified seed light S1, and rotate the light output module 210 into the optical path of the second amplified seed light S2 (i.e., between the first light-transmitting end T1 of the amplifying cavity PA and the first-stage adjustable reflector R1), and install the imaging lens 221 and the light detector 222 at a position where the output light of the second amplified seed light S2, i.e., the second output light SZ2, can be received. Then reinstall the imaging lens 221 on the detection surface of the light detector 222, and then open the image processing software of the control device 230.

[0080] It should be understood here that when the spot size of the once-amplified seed light S1 meets the preset spot size of the once-amplified seed light S1, the light output module 210 in the original optical path tuning device 200 can be rotated into the optical path of the secondary-amplified seed light S2, or a new optical path tuning device 200 can be added, and the light output module 210 in the newly added optical path tuning device 200 can be rotated into the optical path of the secondary-amplified seed light S2.

[0081] In the sixth step, when the secondary amplified seed light S2 is emitted from the amplifying cavity PA, the secondary amplified seed light S2 is transferred out by a reflecting element to form a secondary transferred light SZ2, so that the secondary transferred light SZ2 is received by the imaging lens 221, thereby ensuring that the light detector 222 detects the light spot of the secondary amplified seed light S2.

[0082] In step 7, the control device 230 can measure the spot length X2 and spot width Y2 of the secondary amplified seed light S2 by using the image processing software therein. For the preset characteristic parameters of the secondary amplified seed light S2, the preset length threshold can be X 02 -0.5mm to X 02 +0.5mm, the preset width threshold can be Y 02 -0.2mm to Y 02 +0.2mm. When X2 is at X 02 -0.5mm to X 02 +0.5mm, Y2 is located at Y 02 -0.2mm to Y 02 +0.2mm, it is determined that the spot size of the secondary amplified seed light S2 meets the preset spot size of the secondary amplified seed light S2, and the optical path tuning is completed. If any one of the spot length X2 and the spot width Y2 does not meet the preset characteristic parameters of the secondary amplified seed light S2, the control device 230 can adjust the pitch angle of the second tunable reflector along the direction of arrow C2 and / or adjust the pitch angle of the third tunable reflector along the direction of arrow C3 until both the spot length X2 and the spot width Y2 meet the requirements.

[0083] In practical applications, when adjusting the pitch angle of the second tunable reflector and / or the elevation angle of the second tunable reflector, intermittent adjustment can be performed. For example, when the pitch angle of the second tunable reflector is controlled by a knob, the knob can be controlled to rotate a certain angle, and then paused, and then the next rotation is performed after the image size is stabilized, so as to avoid adjustment errors caused by the asynchronism between the spot image and the movement of the adjustment knob.

[0084] If the pitch angles of the second tunable reflector and the third tunable reflector have been (slightly) adjusted, but the spot size still does not meet the requirements, it means that the spot size of the secondary amplified seed light cannot be directly adjusted using the second tunable reflector and the third tunable reflector. Do not adjust the second tunable reflector and the third tunable reflector at a large angle, return to the first step to readjust the first adjustable reflector, that is, update the pitch angle of the first adjustable reflector. This optical path tuning method can simplify the difficulty of optical path tuning, reduce the difficulty of user operation, and save tuning time.

[0085] like Figure 2 As shown, when the optical path tuning device 200 is integrated with the excimer laser, the embodiment of the present invention further provides an excimer laser device, including the optical path tuning device 200. The light output module 210 included in the optical path tuning device 200 is at least located in the housing of the excimer laser, but the solution that the optical measurement unit 220 and the control device 230 are located in the housing of the excimer laser is not excluded.

[0086] like Figure 2 As shown, when the optical path tuning device 200 includes a light-transmitting window 240, the light-transmitting window 240 is integrated with the housing of the excimer laser. At this time, the optical measurement unit 220 and the control device 230 are located outside the excimer laser. The beneficial effects of the excimer laser device provided by the embodiment of the present invention can refer to the optical path tuning device described above, and will not be repeated here.

[0087] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0088] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An optical path tuning device, characterized in that: Applicable to a laser transmission system having an amplifying cavity and at least one level of adjustable reflector, wherein each level of the adjustable reflector is used to reflect incident seed light toward the amplifying cavity, and the amplifying cavity is used to emit corresponding amplified seed light according to the incident seed light; The optical path tuning device comprises: a light output module, an optical measurement unit and a control device communicating with the optical measurement unit; When the light output module is in the light output mode, the light output module is located in the transmission optical path of the amplifying cavity, and is used to output the amplified seed light emitted by the amplifying cavity to the optical measurement unit; the optical measurement unit is used to measure the optical information of the amplified seed light and send the optical information to the control device; The control device is used to receive the optical information sent by the optical measurement unit, and when it is determined according to the optical information that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters, tune the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters.

2. The optical path tuning device according to claim 1, characterized in that: The light output module is a movable reflective element; the movable reflective element comprises: a driving mechanism and a reflective element arranged on the driving mechanism; wherein, The driving mechanism is a screw-nut mechanism or a linear guide mechanism; and / or, The driving direction of the driving mechanism and the propagation direction of the amplified seed light of the amplifying cavity are greater than 0°.

3. The optical path tuning device according to claim 1, characterized in that: The control device communicates with the light output module; when the light output module is in an idle mode, the light output module is located in a region outside the transmission light path of the amplifying cavity; The control device is used to control the light output module to switch between the idle mode and the light output mode.

4. The optical path tuning device according to any one of claims 1 to 3, characterized in that: The optical measurement unit includes a light detector and an imaging lens arranged on a detection surface of the light detector, and the light detector communicates with the control device; wherein, The imaging lens is a bi-telecentric lens; when the light output module is in the light output mode, the light output module is located within the depth of field of the imaging lens; and / or, The light detector is one of a pyroelectric detector and a magneto-optical effect sensor, and the control device has a display interface.

5. The optical path tuning device according to any one of claims 1 to 3, characterized in that: The optical path tuning device also includes a light-transmitting window for integration on the laser transmission system, the light-transmitting window is located between the light output module and the optical measurement unit, and the light-transmitting window has a light-transmitting lens forming an anti-reflection film.

6. The optical path tuning device according to any one of claims 1 to 3, characterized in that: The control device is used for intermittently tuning the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameter of the amplified seed light and the preset characteristic parameter.

7. The optical path tuning device according to any one of claims 1 to 3, characterized in that: The at least one-stage adjustable reflector comprises a first-stage adjustable reflector and a second-stage adjustable reflector, the amplifying cavity has a first light-transmitting end and a second light-transmitting end, the first-stage adjustable reflector is close to the first light-transmitting end, and the second-stage adjustable reflector is close to the second light-transmitting end; The first-stage adjustable reflector is used to reflect the seed light as incident seed light to the amplifying cavity, so that the amplifying cavity emits amplified seed light once; The second-stage adjustable reflector is used to receive the primary amplified seed light emitted from the amplifying cavity, and reflect the primary amplified seed light as incident seed light to the amplifying cavity, so that the amplifying cavity emits secondary amplified seed light; When the second-stage adjustable reflector includes multiple second-stage adjustable reflectors, the control device is also used to determine that the attitude angles of each of the second-stage adjustable reflectors have been adjusted, and if the characteristic parameters of the secondary amplified seed light do not meet the preset characteristic parameters, when the characteristic parameters of the primary amplified seed light meet the preset characteristic parameters, update the attitude angle of the first-stage adjustable reflector.

8. The optical path tuning device according to any one of claims 1 to 3, characterized in that: The characteristic parameter of the amplified seed light is the spot size of the amplified seed light, and the preset characteristic parameter is the preset spot size, and the preset spot size satisfies the spot size of the amplified seed light of the output light energy of the laser transmission system; wherein, The light spot of the amplified seed light is a rectangular light spot, and the preset characteristic parameters include a preset length threshold and a preset width threshold of the rectangular light spot; the maximum value of the preset length threshold is X0+0.5mm, and the minimum value of the preset length threshold is X0-0.5mm; the maximum value of the preset width threshold is Y0+0.2mm, and the minimum value of the preset length threshold is Y0-0.2mm.

9. A method for optical path tuning, characterized in that: Applicable to an optical path tuning system having a laser transmission system and an optical path tuning device; the laser transmission system comprises an amplifying cavity and at least one level of adjustable reflector, each level of the adjustable reflector is used to provide incident seed light to the amplifying cavity to generate corresponding amplified seed light; The optical path tuning device comprises a light output module, an optical measurement unit and a control device; The optical path tuning method comprises: When the light output module is in the light output mode, the light output module outputs the amplified seed light emitted from the amplifying cavity to the optical measurement unit; The optical measurement unit measures optical information of the amplified seed light and sends the optical information to the control device; The control device receives the optical information sent by the optical measurement unit, and when it is determined according to the optical information that the characteristic parameters of the amplified seed light do not meet the preset characteristic parameters, tunes the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters.

10. The optical path tuning method according to claim 9, characterized in that: When the light output module is in the light output mode before the light output module is in the light output mode, the light path tuning method further includes: the control device controls the light output module to switch from the idle mode to the light output mode; and / or, The step of tuning the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters comprises: the control device intermittently tuning the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameters of the amplified seed light and the preset characteristic parameters; and / or, The at least one-stage adjustable reflector includes a first-stage adjustable reflector and a second-stage adjustable reflector; the first-stage adjustable reflector is used to reflect the seed light as the incident seed light to the amplifying cavity, so that the amplifying cavity emits a first-amplified seed light; the second-stage adjustable reflector is used to receive the first-amplified seed light emitted by the amplifying cavity, and reflect the first-amplified seed light as the incident seed light to the amplifying cavity, so that the amplifying cavity emits a second-amplified seed light; the second-stage adjustable reflector includes a plurality of second-stage adjustable reflectors; After tuning the attitude angle of the adjustable reflector corresponding to the amplified seed light according to the characteristic parameter of the amplified seed light and the preset characteristic parameter, the optical path tuning method further comprises: When the control device determines that the attitude angles of all the second-stage adjustable reflectors have been adjusted, if the characteristic parameters of the secondary amplified seed light do not meet the preset characteristic parameters, and when the characteristic parameters of the primary amplified seed light meet the preset characteristic parameters, the attitude angles of the first-stage adjustable reflectors are updated.

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