JP5376908B2 - Two-stage laser apparatus and adjustment method applied to two-stage laser apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a higher laser output stability and a higher laser output efficiency by reducing a variation in laser output of a two-stage laser device. <P>SOLUTION: In a two-stage laser device equipped with an oscillation stage laser and an amplification stage laser, a cross-sectional profile of a laser beam discharged and excited by the oscillation stage laser 100 and a cross-sectional profile of a laser beam discharged and excited by the amplification stage laser 200 are measured by a beam profiler 401. Based on the measurement results, an adjustment of rotating the cross section of the laser beam discharged and excited by the oscillation stage laser 100 around the optical axis is made by an adjustment means 300 (a plane-convex cylindrical lens and a rotating mechanism of the plane-convex cylindrical lens) in such a manner as to eliminate a deviation between the cross section of the laser beam discharged and excited by the oscillation stage laser 100 and the cross section of the laser beam discharged and excited by the amplification stage laser 200. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a two-stage laser apparatus and an adjustment method applied to the two-stage laser apparatus.

  Currently, an excimer laser is used as a light source for a semiconductor exposure apparatus. In particular, in a technology node of 60 nm or less, an ArF laser light source having a high output of 40 W or more and an ultra-narrow band of 0.2 pm or less is employed.

  The following are required for an ArF laser light source as a light source for an exposure apparatus.

1． With the securing of high dose stability and high throughput, an output of 40 W or more is required.

2． In order to increase the resolution of the projection lens, the NA of the projection lens is being increased. As the NA increases, chromatic aberration occurs, and an ultra-narrow band of 0.2 pm or less is required.

3． There is a demand for extending the life of laser light sources.

  However, an excimer laser device having only one laser chamber has a limit in realizing high output while maintaining an ultra-narrow band spectrum.

Therefore, both the oscillation stage laser apparatus and the amplification stage laser apparatus that have adopted the two stage laser apparatus including the oscillation stage laser apparatus and the amplification stage laser apparatus have a laser gas sealed therein and a pair of opposed discharge electrodes. A laser chamber is provided. When a discharge occurs between the discharge electrodes of the laser chamber of the oscillation stage laser device (hereinafter referred to as the oscillation stage chamber), the laser gas is excited to make a transition to the excited state, and light is further emitted when making a transition from this excited state to the ground state. Occur. When the energy of this light is amplified to some extent, laser light as injection light is output from the oscillation stage laser device. The output injection light is injected into a laser chamber (hereinafter referred to as an amplification stage chamber) of the amplification stage laser apparatus. When a discharge occurs between the discharge electrodes of the amplification stage chamber, the energy of the injected injection light is amplified by the discharge unit and then output from the amplification stage laser apparatus as laser light of the two-stage laser apparatus.

  The two-stage laser apparatus can be roughly divided into two methods. One system is composed of an oscillation stage laser device (referred to as MO) and an amplification stage laser device (referred to as PA) that functions only as an amplifier without an optical resonator. MOPA (Master oscillator Power amplifier) )is called. Another method is composed of an oscillation stage laser device (referred to as MO) and an amplification stage laser device (referred to as PO) having an optical resonator and functioning as an amplifier and an oscillator. Power oscillator).

  The oscillation stage laser device is provided with a narrow band module, and an ultra narrow band spectrum is realized. On the other hand, in the amplification stage laser device, only the energy is amplified while maintaining the ultra narrow band spectrum of the injection light output from the oscillation stage laser apparatus and injected into the amplification stage chamber. According to the two-stage laser apparatus, since the amplification stage laser apparatus does not include a component that causes optical loss such as a narrow-band module, the laser oscillation efficiency is very high. Therefore, a desired ultra-narrow band spectrum and laser output can be obtained. The desired laser power is the product of the pulse energy per pulse and the repetition frequency. For example, the performance required for the next-generation ArF excimer laser is that the spectrum has a full width at half maximum (FWHM) of 0.2 pm or less, and the laser output is 40 W or more when the repetition frequency is 4 kHz.

  FIG. 1 shows an arrangement example of a MOPO type two-stage laser apparatus. FIG. 1A is a side view of the two-stage laser device 1, and FIG. 1B is a top view of the two-stage laser device 1.

  As shown in FIG. 1, the oscillation stage chamber 101 of the oscillation stage laser apparatus 100 and the amplification stage chamber 201 of the amplification stage laser apparatus 200 are provided in order to reduce the footprint of the two stage laser apparatus 1 and to make it compact. Often arranged in parallel and arranged vertically. In this case, two or more high reflection mirrors (high reflection mirrors 11 and 12) are disposed between the oscillation stage chamber 101 and the amplification stage chamber 201, and two or more injection lights emitted from the oscillation stage chamber 101 are emitted. The light enters the amplification stage chamber 201 via the high reflection mirrors (high reflection mirrors 11 and 12).

  Inventions related to the MOPA type and MOPO type two-stage laser devices are described in Patent Documents 1 and 2 below.

  Patent Document 1 describes an invention of a MOPA type two-stage laser apparatus. That is, a narrow-band module is mounted on the oscillation stage laser device (MO), and light is resonated between the narrow-band module and the mirror, thereby forming and outputting light having a very narrow spectrum width. This laser light is injected as injection light into the discharge part between the discharge electrodes of the amplification stage chamber of the amplification stage laser device (PA) to amplify the power of the laser light to obtain an ultra-narrow band and high output. Yes.

Patent Document 2 describes an invention of a MOPO-type two-stage laser apparatus. That is, a narrow-band module is mounted on the oscillation stage laser device (MO), and light is resonated between the narrow-band module and the mirror, thereby forming and outputting light having a very narrow spectrum width. Then, this laser light is injected as injection light into the discharge part between the discharge electrodes of the amplification stage chamber of the amplification stage laser apparatus (PO). In the amplification stage laser device, the discharge is started at the timing of introducing the injection light. As long as the discharge continues in the amplification stage chamber, the light is amplified a plurality of times by the low-coherence optical resonator, and the laser light is finally emitted from the output mirror to the outside. By arranging the optical resonator on the amplification stage laser device side, the amplification effect becomes very high. Therefore, while maintaining the beam quality as in the MOPA method, even if the output of the oscillation stage chamber is small, a sufficiently large laser output can be obtained due to high amplification efficiency, and the time of existence of light in the amplification stage chamber can be obtained. Since it is long, there are advantages such that the discharge start timing in the amplification stage chamber is relatively easy and a long pulse width can be obtained.
US2002 / 0154668 A1 WO 2004/095661 A1

  An object of the present invention is to reduce the variation in laser output of a two-stage laser device, to obtain higher laser output stability and higher laser output.

The following are findings that the present inventors have discovered for the first time.

  For example, in the MOPO type two-stage laser apparatus 1 shown in FIG. 1, the dispersion of the laser output becomes large and the laser output may be lowered. After earnest research on the cause, it became clear that it was the next cause.

a. Since the installation surfaces of the oscillation stage chamber 101 and the amplification stage chamber 201 are different, as shown in FIG. 2A, the cross section 102 of the laser beam of the injection light that is discharged and excited in the oscillation stage chamber 101 and the amplification stage chamber 201 A relative rotation angle difference θ is generated between the cross-sections 202 of the laser beam of the amplification stage light that is discharged and excited.

b. Since two or more high reflection mirrors are installed between the oscillation stage chamber 101 and the amplification stage chamber 201, depending on the installation positions of the oscillation stage chamber 101 and the amplification stage chamber 201, as shown in FIG. In addition, a relative rotation angle difference θ is generated between the cross section 102 of the laser beam of the injection light that is discharged and excited in the oscillation stage chamber 101 and the cross section 202 of the laser beam of the amplification stage light that is discharged and excited in the amplification stage chamber 201.

  The same applies to the MOPA-type two-stage laser apparatus.

  FIGS. 2B and 2C are diagrams for explaining the influence of the relative rotation angle difference θ on the laser output variation and the laser output.

  As shown in FIG. 2 (b), there is a relative gap between the cross section 102 of the laser beam of the injection light excited in the oscillation stage chamber 101 and the cross section 202 of the laser beam of the amplification stage light excited in the amplification stage chamber 201. When there is a rotation angle difference θ, a beam region 203 a in which amplification oscillation is not performed occurs in the discharge unit 203 of the amplification stage chamber 201. The region where the laser beam sections 102 and 202 of the injected light and the amplified stage light overlap in the discharge unit 203 of the amplification stage chamber 201 excluding the beam area 203a is a beam area 203b (shown by oblique lines) where amplification oscillation is performed. is there.

Here, the discharge unit 203 of the amplification stage chamber 201 is a beam gain region that is a space between the discharge electrodes 231 and 232 and in which the laser beam of the amplification stage light is discharge-excited.

  On the other hand, FIG. 2C shows the relative rotation between the cross section 102 of the laser beam of the injection light excited in the oscillation stage chamber 101 and the cross section 202 of the laser beam of the amplification stage light excited in the amplification stage chamber 201. In this example, there is no angular difference θ, and the laser beam cross sections 102 and 202 of the injection light and the amplification stage light coincide with each other. In this case, there is no beam region 203a where amplification oscillation is not performed in the discharge unit 203 of the amplification stage chamber 201, and the entire region of the discharge unit 203 is a beam region 203b where amplification oscillation is performed.

  When the relative rotation angle difference θ shown in FIG. 2B is present, the variation in the laser output increases compared to the state where there is no relative rotation angle difference θ shown in FIG. descend.

As shown in FIG. 2A, if the laser beam cross sections 102 and 202 of the amplification stage light do not coincide with each other, the discharge unit 203 of the amplification stage chamber 201 causes the injection light from the oscillation stage laser apparatus 100 to be This is because a region 203a that does not contribute to amplification occurs, and as a result, the injected light is not sufficiently amplified and the output of the laser decreases. Further, the discharge at the end portion of the discharge portion 203 between the discharge electrodes 231 and 232 is more unstable than the discharge center portion. Since the unstable discharge portion greatly affects the amplified oscillation of the injected light, the variation in laser output becomes large. As a result, the pulse energy of the laser output varies and unstable oscillation occurs.

As shown in FIG. 2B, when there is a beam region 203a that does not oscillate and does not contribute to the amplification of the injected light, a broadband laser beam that is not narrowed is emitted from the discharge unit 203 of the amplification stage chamber 201. As a result, it becomes an apparatus with a lot of ASE (Amplified Spontaneous Emission / parasitic oscillation), making it unsuitable as a laser for exposure.

The inventor conducted an experiment in which the laser beam cross section of the injection light is rotated around the optical axis to measure the variation in the laser output and the laser output.

  3 and 4 show the experimental results. The horizontal axis represents the rotation angle φ of the cross section of the injected laser beam with respect to the reference angle of 0 °, where the angle at the time of high-stable oscillation, that is, the optimum rotation angle is 0 °. The vertical axis in FIG. 3 represents the variation in pulse energy. A reference pulse energy level (for example, 10 mJ) is defined as 100%, and a variation with respect to the reference pulse energy is indicated in%. The vertical axis in FIG. 4 is pulse energy (unit: mJ).

  As can be seen from FIG. 3, the oscillation angle becomes unstable as the rotation angle φ of the cross section of the injected laser beam increases and deviates from the optimum angle of 0 °. In particular, when the rotation angle φ exceeds 2.5 °, the deterioration of oscillation instability becomes significant.

  As can be seen from FIG. 4, the oscillation output decreases as the rotation angle φ of the injection light laser beam cross section increases and deviates from the optimum angle of 0 °. In particular, when the rotation angle φ exceeds 2.5 °, the pulse energy is significantly reduced.

Based on the above findings, the present inventors have recalled the following invention.

The first invention is
In a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
By rotating the cross section of the laser beam discharge-excited by the oscillation stage laser device and / or the cross section of the laser beam discharge-excited by the amplification stage laser apparatus around the optical axis, An adjusting means for matching the cross section with the cross section of the laser beam discharged and excited by the amplification stage laser apparatus is provided.

The second invention is the first invention,
The adjustment means is manually adjusted or automatically controlled so that there is no deviation between the cross section of the laser beam excited by the oscillation stage laser apparatus and the cross section of the laser beam excited by the amplification stage laser apparatus. To do.

The third invention is the first invention,
The adjusting means is characterized in that the adjusting means is manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus is most stabilized.

A fourth invention is the first invention,
The adjusting means is manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus is maximized.

A fifth invention is the first invention,
The adjusting means is manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus is most stabilized and the laser output is maximized.

A sixth invention is the first invention or the second invention,
Measuring means is provided for measuring the cross-sectional profile of the laser beam discharged and excited by the oscillation stage laser apparatus and the cross-sectional profile of the laser beam discharged and excited by the amplification stage laser apparatus,
Based on the measurement results of the measurement means, the adjustment means is manually adjusted so that there is no deviation between the cross section of the laser beam excited by the oscillation stage laser apparatus and the cross section of the laser beam excited by the amplification stage laser apparatus. Or, it is automatically controlled.

The seventh invention is the first invention, the third invention or the fifth invention,
Measuring means for measuring the variation in laser output of the two-stage laser device is provided,
Based on the measurement result of the measuring means, the adjusting means is manually adjusted or automatically controlled so that the variation in the laser output of the two-stage laser apparatus is minimized.

The eighth invention is the first invention, the fourth invention or the fifth invention,
Measuring means for measuring the laser output of the two-stage laser device is provided,
Based on the measurement result of the measuring means, the adjusting means is manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus is maximized.

The ninth invention is the first invention, the third invention, the fourth invention or the fifth invention,
Measuring means for measuring the variation in laser output of the two-stage laser device and the laser output of the two-stage laser device are provided,
Based on the measurement result of the measurement means, the adjustment means is manually adjusted or automatically controlled so that the dispersion of the laser output of the two-stage laser apparatus is minimized and the laser output of the two-stage laser apparatus is maximized. Features.

The tenth invention is the first invention,
The adjusting means is a rotatable optical device provided on the optical axis between the oscillation stage laser apparatus and the amplification stage laser apparatus.

The eleventh invention is the first invention,
The adjusting means is a means for rotating at least one of the oscillation stage laser apparatus and the amplification stage laser apparatus around the optical axis.

In a twelfth aspect based on the tenth aspect,
The optical apparatus includes a plano-convex lens.

The thirteenth invention
An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
Measuring a cross-sectional profile of a laser beam discharge-excited by an oscillation stage laser device and a cross-sectional profile of a laser beam discharge-excited by an amplification stage laser device;
Based on the measurement result, the laser pumped by the oscillation stage laser apparatus so that there is no deviation between the cross section of the laser beam pumped by the oscillation stage laser apparatus and the section of the laser beam pumped by the amplification stage laser apparatus. Adjusting the rotation of the beam cross-section and / or the laser beam cross-section excited by the amplification stage laser device around the optical axis. .

The fourteenth invention is
An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
The cross-sectional profile of the laser beam that is discharged and excited by the oscillation stage laser apparatus is measured while the operation of the amplification stage laser apparatus is stopped, and the discharge excitation is performed by the amplification stage laser apparatus while the operation of the oscillation stage laser apparatus is stopped. Measuring a cross-sectional profile of the laser beam to be produced;
Based on the measurement result, the laser pumped by the oscillation stage laser apparatus so that there is no deviation between the cross section of the laser beam pumped by the oscillation stage laser apparatus and the section of the laser beam pumped by the amplification stage laser apparatus. Adjusting the cross section of the beam or / and rotating the cross section of the laser beam discharge-excited by the amplification stage laser device around the optical axis;
And a step of operating the two-stage laser device after the adjustment. The adjustment method is applied to a two-stage laser device.

The fifteenth invention
An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
Measuring the variation in laser output of the two-stage laser device;
Based on the measurement results, the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus and / or the laser beam excited by the amplification stage laser apparatus so that the variation in the laser output of the two-stage laser apparatus is minimized. And an adjustment method applied to a two-stage laser apparatus including an adjustment step of rotating the cross section around the optical axis.

The sixteenth invention
An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
Measuring the laser output of the two-stage laser device;
Based on the measurement results, the cross section of the laser beam that is discharge-excited by the oscillation stage laser apparatus and / or the cross section of the laser beam that is discharge-excited by the amplification stage laser apparatus so that the laser output of the two-stage laser apparatus is maximized. And an adjustment method applied to a two-stage laser apparatus including an adjustment step of rotating around an optical axis.

The seventeenth invention
An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
Measuring the laser output variation and laser output of the two-stage laser device;
Based on the measurement results, the cross-section or / and amplification of the laser beam that is discharge-excited by the oscillation stage laser device so that the dispersion of the laser output of the two-stage laser device is minimized and the laser output of the two-stage laser device is maximized. An adjustment method applied to a two-stage laser apparatus, comprising: adjusting the section of a laser beam discharge-excited by the stage laser apparatus to rotate around an optical axis.

(Effect of the invention)
According to the present invention, the section of the laser beam excited by the oscillation stage laser apparatus and / or the section of the laser beam excited by the amplification stage laser apparatus is rotated around the optical axis, and the discharge is performed by the oscillation stage laser apparatus. Adjustment was made so that the cross section of the laser beam to be excited and the cross section of the laser beam to be discharged and excited by the amplification stage laser device were matched, so that the variation in the laser output of the two-stage laser device was reduced and the laser output was more stable. And higher laser output can be obtained.

  Embodiments of a two-stage laser apparatus and an adjustment method applied to the two-stage laser apparatus according to the present invention will be described below with reference to the drawings.

(First embodiment: an embodiment in which adjustment is performed from the result of measuring the cross-sectional profile of a laser beam)
FIG. 5 is a diagram showing an apparatus configuration example of the first embodiment, and shows a configuration example of a MOPO type two-stage laser apparatus in a perspective view.

As shown in FIG. 5, the two-stage laser apparatus 1 includes an oscillation stage laser apparatus 100, an amplification stage laser apparatus 200, and a laser beam of injection light that is discharge-excited by the oscillation stage laser apparatus 100 to the amplification stage laser apparatus 200. It comprises high reflection mirrors 11 and 12 for guiding, adjusting means 300, and beam profiler 401 as measuring means 400.

The embodiment apparatus of the present invention is configured by adding an adjusting means 300 and a beam profiler 401 to the existing two-stage laser apparatus 1 shown in FIG. Therefore, the following description will be made with reference to FIGS. 1 and 5 together.

The adjusting means 300 rotates the section of the laser beam of the injection light excited by the oscillation stage laser apparatus 100 around the injection optical axis, and the section of the laser beam of the injection light excited by the oscillation stage laser apparatus 100 Adjustment is performed to match the cross section of the laser beam of the amplification stage light that is discharge-excited by the amplification stage laser apparatus 200.

The adjusting means 300 includes a rotatable optical device provided on the injection optical axis between the oscillation stage laser device 100 and the amplification stage laser device 200 and its rotation mechanism. The optical device includes two plano-convex elements. Cylindrical lenses 301 and 302. Details of the rotating mechanism will be described later with reference to FIGS.

The beam profiler 401 measures the cross-sectional profile of the laser beam of the injection light that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam of the amplification stage light that is discharge-excited by the amplification stage laser apparatus 200. The beam profiler 401 includes a fluorescent screen and a CCD camera. The fluorescent plate is used to visualize ultraviolet light. The fluorescence intensity of the laser light generated on this fluorescent plate indicates the light intensity of the cross section of the laser light. An image corresponding to the fluorescence intensity is picked up by a CCD camera as a cross-sectional image of laser light. When the size of the laser beam is larger than the light receiving portion of the CCD camera, the laser beam is guided to the beam profiler 401 using a convex lens or the like.

The beam profiler 401 is used at the time of adjustment by the adjusting means 300, and is removed when the adjusted two-stage laser apparatus 1 is operated.

The oscillation stage laser device 100 includes an oscillation stage chamber 101, a narrow-band module 110, and an output coupling mirror (Output Coupler) 120. The narrow band module 110 and the output coupling mirror 120 constitute an optical resonator of the oscillation stage laser device 100.

The oscillation stage chamber 101 includes a pair of discharge electrodes 131 and 132. The oscillation stage chamber 101 is filled with buffer gas, Ar gas, and F2 gas. The oscillation stage chamber 101 is provided with windows 141 and 142 for guiding light to the narrow-band module 110 and the output coupling mirror 120, respectively.

When a voltage is applied between the discharge electrodes 131 and 132 by a power source (not shown), a discharge is performed in a discharge portion that is a space between the discharge electrodes 131 and 132, and an ArF excimer is formed by this discharge. When the ArF excimer is separated into Ar gas and F, light having a wavelength of 193 nm is emitted. Thus, the laser beam is discharged and excited.

The narrow band module 110 includes a prism beam expander and a grating (diffraction grating) in order to narrow the spectral line width of the laser beam. The dispersion direction of the grating, that is, the beam expansion direction by the prism beam expander is arranged in a direction perpendicular to the discharge direction of the discharge electrodes 131 and 132 (see FIG. 1A).

The laser beam discharge-excited by the discharge part between the discharge electrodes 131 and 132 is guided to the narrowband module 110 through the window 141, and wavelength selection is performed. The band narrowing module 110 narrows the spectral width of the laser from 400 pm to 0.2 pm or less.

The energy of the laser beam excited by discharge in the discharge part between the discharge electrodes 131 and 132 is amplified by the optical resonator. That is, the light that has passed through the discharge unit is incident on the output coupling mirror 120 through the window 142. Part of the light incident on the output coupling mirror 120 is reflected by the partial reflection surface of the output coupling mirror 120, passes through the discharge unit again, and is guided to the band narrowing module 110 through the window 141. When wavelength selection is performed by the narrowband module 110, the light is reflected toward the discharge unit. Thus, the light repeats resonance a plurality of times between the output coupling mirror 120 and the band narrowing module 110.

Part of the light incident on the output coupling mirror 120 passes through the partial reflection surface of the output coupling mirror 120 and is emitted from the oscillation stage laser device 100 as injection light.
The laser beam transmitted through the output coupling mirror 120 is reflected by the high reflection mirror 11, enters the plano-convex cylindrical lens 301, and passes through the plano-convex cylindrical lens 301. The laser beam transmitted through the plano-convex cylindrical lens 301 is further incident on the plano-convex cylindrical lens 302 and is transmitted through the plano-convex cylindrical lens 302. The laser beam transmitted through the plano-convex cylindrical lens 302 is reflected by the high reflection mirror 12 and is incident on the rear mirror 210 of the amplification stage laser device 200. Here, when the distance from the output coupling mirror 120 of the oscillation stage laser apparatus 100 to the rear mirror 210 of the amplification stage laser apparatus 200 is 1 m or less, the divergence angle of the beam incident on the rear mirror 210 is determined by the output coupling mirror 120. It becomes the same as the spread angle when it is emitted from.

In this embodiment, the plano-convex cylindrical lenses 301 and 302 are arranged between the high reflection mirrors 11 and 12. However, the arrangement position of the plano-convex cylindrical lenses 301 and 302 is the output coupling mirror 120 of the oscillation stage laser device 100. To the rear mirror 210 of the amplification stage laser device 200 can be arranged at any position as long as it is on the injection optical axis. The lens may be a cylindrical lens, and is not limited to a combination of two as in the embodiment, and may be one or three or more.

The amplification stage laser apparatus 200 includes an amplification stage chamber 201, a rear mirror 210, and an output coupling mirror 220. The rear mirror 210 and the output coupling mirror 220 constitute an optical resonator of the amplification stage laser device 200. A beam profiler 401 is disposed at a position facing the amplification stage chamber 201 with the output coupling mirror 220 interposed therebetween.

The amplification stage chamber 201 includes a pair of discharge electrodes 231 and 232. The amplification stage chamber 201 is filled with buffer gas, Ar gas, and F2 gas. The amplification stage chamber 201 is provided with windows 241 and 242 for guiding light to the rear mirror 210 and the output coupling mirror 220, respectively.

When a voltage is applied between the discharge electrodes 231 and 232 by a power source (not shown), a discharge is performed in the discharge unit 203 that is a space between the discharge electrodes 231 and 232, and an ArF excimer is formed by this discharge. When the ArF excimer is separated into Ar gas and F, light having a wavelength of 193 nm is emitted. Thus, the laser beam is discharged and excited.

On the other hand, a part of the beam of injection light emitted from the oscillation stage laser apparatus 100 and incident on the rear mirror 210 is reflected by the rear mirror 210 and is not injected into the optical resonator of the amplification stage laser apparatus 200 but is incident on the rear mirror 210. A part of the injected light beam is injected into the optical resonator of the amplification stage laser device 200.

When the beam of injection light is injected into the discharge part between the discharge electrodes 231 and 232 of the amplification stage chamber 201, the amplification stage laser device 200 starts discharge at the timing of introduction of the injection light. As long as the discharge continues in the amplification stage chamber 201, the light is amplified a plurality of times by the low-coherence optical resonator, and the laser beam is finally emitted from the output coupling mirror 220 to the outside. As described above, in the MOPO-type two-stage laser 1, since the optical resonator is arranged on the amplification stage laser device 200 side, the amplification effect becomes very high.

That is, discharge is performed between the discharge electrodes 231 and 232 in synchronization with the center of the beam of the injection light passing near the center of the rear mirror 210 and passing through the discharge part 203 between the discharge electrodes 231 and 232. Light is amplified. However, a part of the injection light far from the center part of the rear mirror 210 is not amplified because it deviates from the discharge part.

The amplified beam of injected light reaches the output coupling mirror 220 through the window 242. A part of the laser beam reaching the output coupling mirror 220 is reflected by the partial reflection surface of the output coupling mirror 220, passes through the discharge unit again, and is amplified. Then, the laser beam reaches the rear mirror 210 through the window 241, is reflected by the rear mirror 210, passes through the discharge unit again, and is amplified. Thus, the light repeats resonance a plurality of times between the rear mirror 210 and the output coupling mirror 220, and a part of the light incident on the output coupling mirror 220 is transmitted through the partial reflection surface of the output coupling mirror 220 to output light. Is output from the amplification stage laser device 200 to the outside.
At the time of adjustment, the laser beam transmitted through the output coupling mirror 220 is incident on the beam profiler 401. The beam profiler 401 is removed when the two-stage laser apparatus 1 is operated after adjustment. When the beam profiler 401 is removed and the two-stage laser apparatus 1 is operated, the laser beam transmitted through the output coupling mirror 220 is guided to an external exposure apparatus.

FIG. 6 is a diagram for explaining the principle that the injection light is rotated by the rotation of the plano-convex cylindrical lenses 301 and 302. A case where one plano-convex cylindrical lens 302 is rotated on the injection optical axis will be described as an example.

6A and 6B are perspective views seen from different angles, and FIGS. 6C and 6D are virtual screens 501 and 502 shown in FIGS. 6A and 6B, respectively. 2 illustrates an example of a cross section of a laser beam irradiated on the substrate.

As shown in FIG. 6A, the injected light propagates from the left to the right in the figure and sequentially passes through the plano-convex cylindrical lenses 301 and 302. The lens system is a transfer type and transfers an incident beam profile as an outgoing beam profile. That is, the beam profile size, shape, and beam divergence are not affected.

As shown in FIG. 6B, the beam profile of the injection light before entering the planoconvex cylindrical lens 301, that is, the beam cross-sectional image on the screen 501 (FIG. 6C) is a reference angle around the injection optical axis. The posture is rotated by A ° to the right in the figure with respect to (optimal angle). The injected light sequentially passes through the plano-convex cylindrical lenses 301 and 302. At this time, when the plano-convex cylindrical lens 302 is rotated A ° clockwise around the injection optical axis, the plano-convex cylindrical lens 302 is emitted. The subsequent injection light rotates around the injection optical axis, and the beam profile after emission, that is, the beam cross-sectional image on the screen 502 (FIG. 6D) is corrected to the reference angle (optimal angle). . Thus, when the incident light to the plano-convex cylindrical lens 301 is rotated by A °, if the plano-convex cylindrical lens 302 is rotated by the same angle A ° in the same direction, the angle from the reference angle (optimal angle) The deviation of A ° can be corrected.

In FIG. 6, the case where one plano-convex cylindrical lens 302 is rotated around the injection optical axis has been described as an example. However, the same correction may be performed by rotating the other plano-convex cylindrical lens 301. The same correction may be performed by rotating both the convex cylindrical lenses 301 and 302.

Further, the adjusting means 300 of the present embodiment is constituted by a transfer type combined lens using two plano-convex cylindrical lenses, but it is sufficient if there is a rotating lens system, not a transfer type combined lens but a condensing lens system. It may be.

Next, the adjustment method of the first embodiment will be described. The adjustment method is as follows.

(Measurement step)
First, the beam profiler 401 measures the cross-sectional profile of the laser beam that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam that is discharge-excited by the amplification stage laser apparatus 200.

(Adjustment step)
Next, on the basis of the measurement result, the oscillation stage laser apparatus 100 eliminates the deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200. Adjustment for rotating the cross section of the laser beam excited by discharge around the optical axis is performed by the adjusting means 300 (plano-convex cylindrical lens and plano-convex cylindrical lens rotation mechanism) (see FIG. 6).

More specific adjustment methods are as follows.

(Measurement step)
While the operation of the amplification stage laser apparatus 200 is stopped, the cross-sectional profile of the laser beam that is discharged and excited by the oscillation stage laser apparatus 100 is measured by the beam profiler 401, and the operation of the oscillation stage laser apparatus 100 is stopped. A beam profiler 401 measures a cross-sectional profile of a laser beam that is discharge-excited by the amplification stage laser device 200.

(Adjustment step)
Based on the measurement result, the oscillation excitation is performed in the oscillation stage laser apparatus 100 so that there is no deviation between the cross section of the laser beam excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam excited by the amplification stage laser apparatus 200. The adjustment of rotating the cross section of the laser beam around the optical axis is performed by the preparation means 300 (plano-convex cylindrical lens and plano-convex cylindrical lens rotation mechanism) (see FIG. 6).

(Operation step)
After the adjustment, the two-stage laser apparatus 1 is operated. For example, an output laser emitted from the two-stage laser apparatus 1 enters the exposure apparatus, and exposure is performed.

This is shown in the flowchart of FIG. Hereinafter, description will be given with reference to this flowchart.

That is, first, the oscillation of the oscillation stage laser is stopped (step 1001).

Next, the amplification stage laser is oscillated (step 1002).

Next, the beam profiler 401 measures the beam profiler (cross-sectional profile) BP-AMP of the amplified stage light (step 1003).

Next, the oscillation of the amplification stage laser is stopped (step 1004).

Next, the oscillation stage laser is oscillated (step 1005).

Next, the injection light that has passed through the amplification stage chamber 201 whose oscillation is stopped is received by the beam profiler 401 (step 1006).

Next, a beam profiler (cross-sectional profile) BP-OSC of injected light is measured by the beam profiler 401 (step 1007).

Next, the beam profiler (cross-sectional profile) BP-AMP of the amplification stage light and the beam profiler (cross-sectional profile) BP-OSC of the injected light are compared (step 1008).

Next, the plano-convex cylindrical lens 302 is rotated on the injection optical axis so that the beam profiler (cross-sectional profile) BP-AMP of the amplification stage light and the beam profiler (cross-sectional profile) BP-OSC of the injection light coincide. For example, the beam profiler (cross-sectional profile) BP-AMP of the amplification stage light is the reference angle, and the beam profiler (cross-sectional profile) BP-OSC of the injection light is shifted from the reference angle (optimum angle) by an angle A °. In this case, as shown in FIGS. 6C and 6D, the planoconvex cylindrical lens 302 is rotated by A ° around the injection optical axis to correct the deviation, and both beam profilers (cross-sectional profiles) BP-AMP are corrected. BP-OSC should be matched. That is, as described with reference to FIGS. 2A, 2 </ b> B, and 2 </ b> C, the cross section 102 of the laser beam that is discharge-excited in the oscillation stage chamber 101 and the cross section 202 of the laser beam that is discharge-excited in the amplification stage chamber 201. They are matched so that there is no relative rotation angle difference θ between them (step 1009).

After the adjustment, the two-stage laser apparatus 1 is operated to perform exposure.

In FIG. 7, the beam profiler (cross-sectional profile) BP-AMP of the amplification stage light is measured, and then the beam profiler (cross-sectional profile) BP-OSC of the injected light is measured. After measuring the cross-sectional profile) BP-OSC, the beam profiler (cross-sectional profile) BP-AMP of the amplified stage light may be measured.

The adjustment of the adjusting unit 300 may be manual or automatic control. For example, a rotation mechanism that can manually rotate the plano-convex cylindrical lens 302 around the injection optical axis may be provided, and the plano-convex cylindrical lens 302 may be rotated by manually operating the rotation mechanism. In addition, a rotation actuator that rotates the plano-convex cylindrical lens 302 around the injection optical axis is provided, and a controller that controls the rotation actuator is provided, and the plano-convex cylindrical lens 302 is rotated according to a command signal output from the controller to the rotation actuator. You may let them.

FIGS. 8A to 8D are diagrams showing examples of each configuration of the rotation mechanism of the planoconvex cylindrical lens from two directions. Each of these is a configuration example in which the planoconvex cylindrical lens 302 is manually operated with a micrometer, and the configuration of the housing is different. In either case, the plano-convex cylindrical lens 302 is disposed in the housing 350, and the plano-convex cylindrical lens 302 can be rotated by the operation of the knob 351. 8C and 8D, a coarse motion rotation knob 351a and a fine motion rotation knob 351b are provided to vary the rotation amount of the plano-convex cylindrical lens 302 per unit operation amount. When the coarse operation rotating knob 351a is operated by the unit operation amount, the plano-convex cylindrical lens 302 is rotated greatly, and when the fine movement rotation knob 351b is operated by the unit operation amount, the plano-convex cylindrical lens 302 is rotated small.

FIGS. 9A, 9B, and 9C are diagrams illustrating a configuration example of the rotation actuator of the planoconvex cylindrical lens viewed from three directions.

9A, 9 </ b> B, and 9 </ b> C, a portion corresponding to the knob 351 in FIG. 8 is replaced with a motor 352. A motor control cable 353 is connected to the motor 352, and a controller (not shown) is connected to the motor control cable 353. When a command signal is output from the controller to the motor 352 via the motor control cable 353, the plano-convex cylindrical lens 302 is rotated according to the command signal.

In the above description, the case where a rotatable plano-convex cylindrical lens is used as the adjusting unit 300 has been described as an example. However, the adjusting means 300 may be any rotatable optical device provided on the injection optical axis between the oscillation stage laser apparatus 100 and the amplification stage laser apparatus 200, and includes a configuration including a cylindrical lens, other than the cylindrical lens. Any configuration using an optical device may be used.

FIG. 10 shows an embodiment in which a rotating cylindrical mirror 303 and a cylindrical lens 304 are used as the adjusting means 300. FIG. 10A is a perspective view of the overall configuration, and FIG. 10B is an enlarged perspective view of the cylindrical mirror 303. The cylindrical mirror 303 has a curvature that is curved in the horizontal direction, and is formed so that there is no curvature in the vertical direction.

The injection light can be rotated by rotating the cylindrical mirror 303 around the injection optical axis.

In FIG. 10, the case where the cylindrical mirror 303 is rotated around the injection optical axis has been described as an example. However, the cylindrical lens 304 is rotated around the injection optical axis in the same manner as described in FIG. It may be rotated, and the same correction may be performed by rotating both the cylindrical mirror 303 and the cylindrical lens 304.

In the embodiment described above, the section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 is rotated around the optical axis, and the section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 and the amplification stage laser apparatus 200 are rotated. An adjustment is made so that the cross section of the laser beam excited by discharge coincides, but the cross section of the laser beam excited by the amplification stage laser apparatus 200 is rotated around the optical axis, and the discharge is performed by the oscillation stage laser apparatus 100. The cross section of the laser beam to be excited may coincide with the cross section of the laser beam to be discharged and excited by the amplification stage laser apparatus 200. Further, the laser beam cross section of the laser beam excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge excited by the amplification stage laser apparatus 200 are rotated around the optical axis, and the discharge excitation is performed by the oscillation stage laser apparatus 100. The cross section of the laser beam and the cross section of the laser beam excited by the amplification stage laser device 200 may be matched.

(Effect of the invention according to the first embodiment)
According to the first embodiment, the cross-sectional profile of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam discharge-excited by the amplification stage laser apparatus 200 are measured, and based on the measurement result, Since the optical device is rotated and adjusted so that there is no deviation between the cross section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharged and excited by the amplification stage laser apparatus 200, Variations in the laser output of the two-stage laser apparatus 1 are reduced, and higher laser output stability and higher laser output can be obtained.

In the first embodiment described above, the cross-sectional profile of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam discharge-excited by the amplification stage laser apparatus 200 are measured, and based on the measurement results, The optical device is rotated so that adjustment is made so that there is no deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200.

However, it is also possible to measure the variation in the laser output of the two-stage laser device 1 and perform adjustment so that the variation in the laser output of the two-stage laser device 1 is minimized based on the measurement result. This will be described below in the second embodiment.

(Second embodiment: an embodiment in which adjustment is performed from the result of measuring the variation in laser output)
FIG. 11 is a diagram showing an apparatus configuration example of the second embodiment, and is a perspective view showing a configuration example of a MOPO type two-stage laser apparatus. In the following, description of the parts common to the first embodiment will be omitted.

11 differs from the apparatus configuration shown in FIG. 5 in that a laser energy detector 402 that detects the laser output (laser energy) of the output laser light of the two-stage laser apparatus 1 instead of the beam profiler 401 as the measuring means 400. A laser control device 403 that measures variations in laser output based on the laser output detected by the laser energy detector 402, and a beam splitter 404 for guiding the output laser light to the laser energy detector 402. It is. The laser energy detector 402, the laser control device 403, and the beam splitter 404 are originally provided for performing normal measurement and control in the apparatus configuration shown in FIG. 5, but are shown in FIG. Is omitted.

The beam splitter 404 is disposed at a position facing the amplification stage chamber 201 with the output coupling mirror 220 interposed therebetween. The laser energy detector 402 is arranged in a direction in which light is reflected by the beam splitter 404. The laser energy detector 402 is connected to the laser control device 403. The laser control device 403 includes a computer.

A part of the laser light emitted from the output coupling mirror 220 passes through the beam splitter 404 and is guided to an external exposure apparatus. However, a part of the laser light is reflected by the beam splitter 404, and the laser energy detector 402. Is incident on. The laser output detected by the laser energy detector 402 is input to the laser control device 403, and the dispersion of the laser output is measured.

The measured value may be a variation in pulse energy, or may be a variation in laser output (a laser output is a product of pulse energy per pulse and repetition frequency).

As described with reference to FIG. 3, as the rotation angle φ of the cross section of the injected laser beam increases and deviates from the optimum angle of 0 °, the pulse energy varies and the oscillation becomes unstable. Therefore, the adjustment means 300 may be manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus 1 is most stabilized. Specifically, while measuring the laser output variation (pulse energy variation), the laser output variation (pulse energy variation) is minimized (the value at the optimum angle of 0 ° in FIG. 3). The adjustment by the adjusting means 300, that is, the adjustment for rotating the optical device may be performed manually or automatically. In the case of performing automatic control, the laser control device 403 may have a controller function for automatically controlling the adjusting unit 300. Of course, the laser energy detector 402, the laser control device 403, and the beam splitter 404 function to perform normal measurement and control, and separately from these, measurement of variation in laser output and variation in laser output according to the present invention. It is also possible to provide an equivalent device that performs control to minimize the above.

Next, the adjustment method of the second embodiment will be described. The adjustment method is as follows.

(Measurement step)
Variation in laser output of the two-stage laser apparatus 1 is measured.

(Adjustment step)
Based on the measurement result, adjustment means 300 (adjustment for rotating the section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 around the optical axis so that the variation in the laser output of the two-stage laser apparatus 1 is minimized. The rotation mechanism is a plano-convex cylindrical lens and a plano-convex cylindrical lens rotation mechanism).

  The adjustment may be performed before the two-stage laser apparatus 1 is in operation, or may be performed while the two-stage laser apparatus 1 is in operation.

In the adjustment step, the cross section of the laser beam discharged and excited by the amplification stage laser apparatus 200 may be rotated around the optical axis, and the cross section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 and The cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200 may be rotated around the optical axis.

(Effect of the invention according to the second embodiment)
In the second embodiment, the variation in the laser output of the two-stage laser device 1 is measured, and the optical device is rotated so that the variation in the laser output of the two-stage laser device 1 is minimized based on the measurement result. Therefore, the variation in the laser output of the two-stage laser apparatus 1 is reduced, and higher laser output stability can be obtained.

(3rd Example: Example which adjusts from the result of having measured the laser output)
In the following, the description of the parts common to the first embodiment and the second embodiment will be omitted.

The configuration of the third embodiment is the same as that of the second embodiment shown in FIG. 11, and a laser energy detector 402, a laser control device 403, and a beam splitter 404 are provided. However, measurement contents and control contents are different.

A part of the laser light emitted from the output coupling mirror 220 passes through the beam splitter 404 and is guided to an external exposure apparatus. However, a part of the laser light is reflected by the beam splitter 404, and the laser energy detector 402. Is incident on. The laser output detected by the laser energy detector 402 is input to the laser controller 403, and the laser output is measured.

The measured value may be pulse energy or laser output (laser output is the product of pulse energy per pulse and repetition frequency).

As described with reference to FIG. 4, as the rotation angle φ of the cross section of the injected laser beam increases and deviates from the optimum angle of 0 °, the pulse energy decreases and the oscillation output decreases. Therefore, the adjustment unit 300 may be manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus 1 is maximized. Specifically, the laser output (pulse energy) is measured, and the adjustment by the adjusting means 300 is performed so that the laser output (pulse energy) becomes maximum (value at the optimum angle of 0 ° in FIG. 4), that is, optical. Adjustment for rotating the device may be performed manually or automatically. In the case of performing automatic control, the laser control device 403 may have a controller function for automatically controlling the adjusting unit 300. Of course, the laser energy detector 402, the laser control device 403, and the beam splitter 404 function to perform normal measurement and control, and separately from these, the laser output measurement and laser output according to the present invention are maximized. It is possible to provide an equivalent device for controlling.

Next, an adjustment method of the third embodiment will be described. The adjustment method is as follows.

(Measurement step)
The laser output of the two-stage laser apparatus 1 is measured.

(Adjustment step)
Based on the measurement result, adjustment means 300 (plano-convex) is used to rotate the section of the laser beam excited by the oscillation stage laser apparatus 100 around the optical axis so that the laser output of the two-stage laser apparatus 1 is maximized. Rotation mechanism of cylindrical lens and plano-convex cylindrical lens).

  The adjustment may be performed before the two-stage laser apparatus 1 is in operation, or may be performed while the two-stage laser apparatus 1 is in operation.

In the adjustment step, the cross section of the laser beam discharged and excited by the amplification stage laser apparatus 200 may be rotated around the optical axis, and the cross section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 and The cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200 may be rotated around the optical axis.

(Effect of the invention according to the third embodiment)
In the third embodiment, the laser output of the two-stage laser apparatus 1 is measured, and based on the measurement result, the optical device is rotated so that the laser output of the two-stage laser apparatus 1 is maximized. The stage laser device 1 can obtain a higher laser output.

(4th Example: Example which adjusts from the result of having measured the dispersion | variation in a laser output, and a laser output)
In the following, description of the parts common to the first embodiment, the second embodiment, and the third embodiment will be omitted.

The configuration of the fourth embodiment is the same as that of the second embodiment shown in FIG. 11, and a laser energy detector 402, a laser control device 403, and a beam splitter 404 are provided. However, measurement contents and control contents are different.

A part of the laser light emitted from the output coupling mirror 220 passes through the beam splitter 404 and is guided to an external exposure apparatus. However, a part of the laser light is reflected by the beam splitter 404, and the laser energy detector 402. Is incident on. The laser control device 403 receives the laser output detected by the laser energy detector 402, and measures the laser output and the variations in the laser output.

The measured value may be pulse energy and pulse energy variation, or may be laser output (laser output is the product of pulse energy per pulse and repetition frequency) and laser output variation.

As described with reference to FIG. 3, as the rotation angle φ of the cross section of the injected laser beam increases and deviates from the optimum angle of 0 °, the pulse energy varies and the oscillation becomes unstable. In addition, as described with reference to FIG. 4, the rotation angle φ of the cross section of the injected laser beam increases, and the pulse energy decreases and the oscillation output decreases as the optimum angle deviates from 0 °. Therefore, the adjustment means 300 may be manually adjusted or automatically controlled so that the laser output of the two-stage laser apparatus 1 is most stabilized and the laser output is maximized. Specifically, while measuring the laser output (pulse energy), the laser output (pulse energy) is maximized (value at the optimum angle of 0 ° in FIG. 4), and the laser output (pulse energy) is measured. The adjustment by the adjusting means 300, that is, the adjustment for rotating the optical device is manually performed so that the variation in the laser output (pulse energy) is minimized (the value at the optimum angle of 0 ° in FIG. 3) Alternatively, automatic control may be performed. In the case of performing automatic control, the laser control device 20 may have a controller function for automatically controlling the adjusting unit 300. Of course, the laser energy detector 402, the laser control device 403, and the beam splitter 404 function to perform normal measurement and control, and separately from these, measurement of laser output and output variation, laser output according to the present invention. It is also possible to provide an equivalent device that performs control to maximize the power and minimize the variation in laser output.

Next, an adjustment method of the fourth embodiment will be described. The adjustment method is as follows.

(Measurement step)
The laser output of the two-stage laser apparatus 1 and the variation in the laser output are measured.

(Adjustment step)
Based on the measurement result, the laser that is discharge-excited by the oscillation stage laser apparatus 100 so that the laser output of the two-stage laser apparatus 1 is maximized and the variation in the laser output of the two-stage laser apparatus 1 is minimized. Adjustment for rotating the cross section of the beam around the optical axis is performed by the adjusting means 300 (plano-convex cylindrical lens and plano-convex cylindrical lens rotation mechanism).

  The adjustment may be performed before the two-stage laser apparatus 1 is in operation, or may be performed while the two-stage laser apparatus 1 is in operation.

In the adjustment step, the cross section of the laser beam discharged and excited by the amplification stage laser apparatus 200 may be rotated around the optical axis, and the cross section of the laser beam discharged and excited by the oscillation stage laser apparatus 100 and The cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200 may be rotated around the optical axis.

(Effect of the invention according to the fourth embodiment)
In the fourth embodiment, the laser output of the two-stage laser apparatus 1 and the variations in the laser output are measured, and based on the measurement result, the laser output of the two-stage laser apparatus 1 is maximized, and the two-stage laser apparatus 1 Since the optical device is rotated so that the variation in the laser output is minimized, the variation in the laser output of the two-stage laser apparatus 1 is reduced, and higher laser output stability and higher laser output can be obtained. .

  In the above-described first to fourth embodiments, the description has been given of the case where adjustment for rotating an optical device such as a planoconvex cylindrical lens or a mirror is performed. However, the cross section of the laser beam may be rotated by adjusting the rotation of the laser chamber (the oscillation stage chamber 101 or / and the amplification stage chamber 201).

In the following fifth and sixth embodiments, the adjusting means 300 is constituted by means for rotating at least one of the laser chambers 101 and 201 of the oscillation stage laser apparatus 100 and the amplification stage laser apparatus 200 around the optical axis.

(Fifth embodiment: an embodiment in which adjustment is made to rotate the oscillation stage chamber)
A case where the oscillation stage chamber 101 is rotated will be described.

FIG. 12 is a diagram showing an apparatus configuration example of the fifth embodiment, and shows a configuration example of a MOPO type two-stage laser apparatus in a perspective view. In the following, description of the parts common to the first embodiment will be omitted.

12 is the same as the apparatus configuration shown in FIG. 5 in that a beam profiler 401 is provided as the measuring unit 400, but the adjusting unit is composed of a rotatable optical device (plano-convex cylindrical lenses 301 and 302). The apparatus configuration shown in FIG. 5 is that an adjusting means 300 configured by a rotation mechanism 310 that rotates the oscillation stage chamber 101 around the injection optical axis by rotating the oscillation stage chamber 101 instead of the rotation stage chamber 101 is provided. And different.

FIG. 13B shows a configuration example of the rotation mechanism 310. FIG. 13A shows a state where the oscillation stage chamber 101 is inclined with respect to the vertical axis. FIGS. 13A and 13B are views of the oscillation stage chamber 101 as viewed from the side from which the injection light is emitted, that is, from the window 142 side.

As shown in FIG. 13B, the rotation mechanism 310 is provided so as to protrude upward on the left and right of the chamber support table 311 for supporting the oscillation stage chamber 101 and the chamber support table 311 in the drawing, depending on the screwing amount. The screws 312 and 313 push up the left and right sides of the oscillation stage chamber 101, respectively.

As shown in FIG. 13A, it is assumed that the oscillation stage chamber 101 rotates around the injection optical axis and is inclined with respect to the vertical axis. At this time, the output coupling mirror 120, the window 142, and the discharge electrodes 131 and 132 are inclined with respect to the vertical axis, and the cross section (beam profile) 102 of the laser beam of the injection light formed between the discharge electrodes 131 and 132 is vertical. It will be inclined with respect to the axis. Therefore, as described with reference to FIG. 2, the cross section 102 of the laser beam of the injection light injected into the amplification stage chamber 201 via the high reflection mirrors 11 and 12 and the cross section of the laser beam discharge-excited in the amplification stage chamber 201. A relative rotational angle difference θ occurs between 202 (assuming that the amplification stage chamber 201 is not inclined with respect to the vertical axis). As a result, a beam region 203a in which amplification oscillation is not performed occurs in the discharge unit 203 (beam gain region) of the amplification stage chamber 201, and high output and high stability oscillation cannot be realized.

Therefore, the screwing amounts of the screws 312 and 313 are adjusted manually or automatically. As a result, the amount of left and right protrusion of the chamber support 311 can be adjusted. As a result, the left and right sides of the oscillation stage chamber 101 are pushed up by a desired amount, the oscillation stage chamber 101 rotates around the injection optical axis, and the oscillation stage chamber 101 has a desired inclination, that is, a posture not inclined with respect to the vertical axis. . As a result, as described with reference to FIG. 2, the relative rotation angle difference θ between the cross sections of both the injected light and the amplified stage light is eliminated, and high output and highly stable oscillation is realized.

The procedure of the adjustment method is the same as the procedure of the adjustment method of the first embodiment described above, and is performed as follows.

(Measurement step)
First, the beam profiler 401 measures the cross-sectional profile of the laser beam that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam that is discharge-excited by the amplification stage laser apparatus 200.

(Adjustment step)
Next, on the basis of the measurement result, the oscillation stage laser apparatus 100 eliminates the deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200. Adjustment for rotating the cross section of the laser beam to be discharged around the optical axis is performed by the adjustment means 300 (the rotation mechanism 310 of the oscillation stage chamber 101).

The rotation mechanism 310 illustrated in FIG. 13B is an example, and a rotation mechanism having a configuration other than the tilting of the oscillation stage chamber 101 by pushing up a screw may be employed.

FIGS. 14A, 14 </ b> B, and 14 </ b> C illustrate other configuration examples of the rotation mechanism 310 in perspective views.

As shown in FIGS. 14A, 14 </ b> B, and 14 </ b> C, the lower end of the oscillation stage chamber 101 is composed of a plate portion 150. The oscillation stage chamber 101 is supported from below by the laser frame 30. Left and right adjustment members 314 that adjust the distance between the laser frame 30 and the plate part 150 on the left and right respectively are provided on the left and right sides of the plate part 150 of the oscillation stage chamber 101.

FIG. 14A illustrates a case where the left / right adjustment member 314 is configured by a screw. By adjusting the screwing amounts of the left and right screws, the distance between the left and right laser frames 30 and the plate portion 150 is adjusted. Thereby, the left and right heights of the oscillation stage chamber 101 are adjusted, the oscillation stage chamber 101 rotates around the injection optical axis, and the oscillation stage chamber 101 can be set to a desired inclination.

FIG. 14B illustrates a case where the left and right adjustment member 314 is configured by a shim. By inserting shims on the left and right sides, the distance between the left and right laser frames 30 and the plate portion 150 is adjusted. Thereby, the left and right heights of the oscillation stage chamber 101 are adjusted, the oscillation stage chamber 101 rotates around the injection optical axis, and the oscillation stage chamber 101 can be set to a desired inclination. A spacer may be used instead of the shim.

FIG. 14C illustrates a case where the left / right adjustment member 314 is configured by a jack. By operating the left and right jacks, the distance between the left and right laser frames 30 and the plate portion 150 is adjusted. Thereby, the left and right heights of the oscillation stage chamber 101 are adjusted, the oscillation stage chamber 101 rotates around the injection optical axis, and the oscillation stage chamber 101 can be set to a desired inclination. The jack can be operated by any driving source such as hydraulic pressure or pneumatic pressure.

In the case of the rotation mechanism 300 using the screw and jack described above, the rotation mechanism 300 can be adjusted not only manually but also by automatic control. However, in the case of the rotation mechanism 300 using shims and spacers, it is desirable to perform manual adjustment. For example, at the stage of shipping the two-stage laser apparatus 1 to the market, shims or spacers are inserted and adjustment is performed.

(Sixth embodiment: an embodiment in which an amplification stage chamber is rotated)
Next, a case where the amplification stage chamber 201 is rotated will be described.

FIG. 15 is a diagram showing an apparatus configuration example of the sixth embodiment, and shows a configuration example of a MOPO type two-stage laser apparatus in a perspective view. In the following, description of the parts common to the first embodiment will be omitted.

15 is the same as the apparatus configuration shown in FIG. 5 in that a beam profiler 401 is provided as the measurement unit 400, but an adjustment unit configured with rotatable optical devices (plano-convex cylindrical lenses 301 and 302). Instead of 300, an adjustment means 300 configured by a rotation mechanism 310 that rotates the amplification stage chamber 201 to rotate the laser beam excited by discharge in the amplification stage chamber 201 around the injection optical axis is provided. Different from the apparatus configuration shown in FIG.

FIG. 16B shows a configuration example of the rotation mechanism 310. FIG. 16A shows a state where the amplification stage chamber 201 is inclined with respect to the vertical axis. FIGS. 16A and 16B are views of the amplification stage chamber 201 as viewed from the side from which the output laser light is emitted, that is, from the window 242 side.

The rotation mechanism 310 is configured in the same manner as the rotation mechanism 310 shown in FIG.

As shown in FIG. 16A, it is assumed that the amplification stage chamber 201 rotates around the injection optical axis and is inclined with respect to the vertical axis. At this time, the output coupling mirror 220, the window 242, and the discharge electrodes 231 and 232 are inclined with respect to the vertical axis, and the cross section (beam profile) 202 of the laser beam formed between the discharge electrodes 231 and 232 is with respect to the vertical axis. Will be inclined. Therefore, as described with reference to FIG. 2, the cross section 102 of the laser beam of the injection light injected into the amplification stage chamber 201 via the high reflection mirrors 11 and 12 and the cross section of the laser beam discharge-excited in the amplification stage chamber 201. A relative rotation angle difference θ occurs between 202 (assuming that the oscillation stage chamber 101 is not inclined with respect to the vertical axis). As a result, a beam region 203a in which amplification oscillation is not performed occurs in the discharge unit 203 (beam gain region) of the amplification stage chamber 201, and high output and high stability oscillation cannot be realized.

Therefore, the screwing amounts of the screws 312 and 313 are adjusted manually or automatically. As a result, the amount of left and right protrusion of the chamber support 311 can be adjusted. As a result, the left and right sides of the amplification stage chamber 201 are pushed up by a desired amount, the amplification stage chamber 201 rotates around the injection optical axis, and the amplification stage chamber 201 has a desired inclination, that is, a posture not inclined with respect to the vertical axis. . As a result, as described with reference to FIG. 2, the relative rotation angle difference θ between the cross sections of both the injected light and the amplified stage light is eliminated, and high output and highly stable oscillation is realized.

The procedure of the adjustment method is the same as the procedure of the adjustment method of the first embodiment described above, and is performed as follows.

(Measurement step)
First, the beam profiler 401 measures the cross-sectional profile of the laser beam that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam that is discharge-excited by the amplification stage laser apparatus 200.

(Adjustment step)
Next, on the basis of the measurement result, the amplification stage laser apparatus 200 eliminates the deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200. Adjustment for rotating the cross section of the laser beam to be discharged around the optical axis is performed by the adjustment means 300 (the rotation mechanism 310 of the amplification stage chamber 201).

The rotation mechanism 310 shown in FIG. 16B is an example, and has a configuration other than that in which the amplification stage chamber 201 is tilted by pushing up the screw, as in FIGS. 14A, 14B, and 14C described above. It is also possible to employ a rotation mechanism.

(Seventh embodiment: an embodiment in which the oscillation stage chamber and the amplification stage chamber are adjusted to rotate)
The oscillation stage chamber 101 can be rotated as in the fifth embodiment, and the adjustment for rotating the amplification stage chamber 201 can be performed in combination as in the sixth embodiment.

The procedure of the adjustment method is the same as the procedure of the adjustment method of the first embodiment described above, and is performed as follows.

(Measurement step)
First, the beam profiler 401 measures the cross-sectional profile of the laser beam that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam that is discharge-excited by the amplification stage laser apparatus 200.

(Adjustment step)
Next, on the basis of the measurement result, the oscillation stage laser apparatus 100 eliminates the deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200. Adjustment means 300 (oscillation stage chamber 101 and rotation stage 310 of amplification stage chamber 201) for adjusting the cross section of the laser beam excited by discharge and the section of the laser beam excited by discharge in amplification stage laser apparatus 200 around the optical axis. To do.

  In the fifth embodiment, the sixth embodiment, and the seventh embodiment, the adjustment by the rotation mechanism 310 is performed based on the measurement result of the cross-sectional profile of the laser beam, but the second embodiment, the third embodiment, As described in the fourth embodiment, based on the measurement result of the laser output variation, or based on the measurement result of the laser output, or based on the variation of the laser output and the measurement result of the laser output, Adjustment by the rotation mechanism 310 may be performed.

(Effects of the inventions according to the fifth, sixth and seventh embodiments)
According to the fifth, sixth, and seventh embodiments, the cross section of the laser beam is rotated by adjusting the rotation of the laser chamber (the oscillation stage chamber 101 and / or the amplification stage chamber 201). Therefore, the variation in the laser output of the two-stage laser apparatus 1 is reduced, and higher laser output stability and higher laser output can be obtained.

(Eighth embodiment: an embodiment in which adjustment is made to rotate the slit (or aperture))
FIG. 17 is a diagram showing an apparatus configuration example of the eighth embodiment, and shows a configuration example of a MOPO type two-stage laser apparatus in a perspective view. In the following, description of the parts common to the first embodiment will be omitted.

In FIG. 17, the beam profiler 401 is provided as the measuring unit 400 in the same way as the apparatus configuration shown in FIG. 5, but instead of the adjusting unit 300 including the rotatable plano-convex cylindrical lenses 301 and 302. 5 is different from the apparatus configuration shown in FIG. 5 in that an adjusting means 300 including a rotatable slit 320 is provided. It is also possible to provide an aperture instead of the slit 320.

  The slit 320 is disposed on the injection optical axis between the high reflection mirror 11 and the high reflection mirror 12. The slit 320 is configured to be rotatable around the injection optical axis, and is rotated manually or automatically. The rotation mechanism of the slit 320 can be configured similarly to the rotation mechanism of the plano-convex cylindrical lens shown in FIGS.

  However, the size of the laser beam of the injection light emitted from the oscillation stage laser device 100 is larger than the size of the slit 320, and the size of the laser beam of the injection light after passing through the slit 320 is the discharge part of the amplification stage chamber 201. The size needs to be large enough to efficiently extract the laser output from 203 (beam gain region). Further, the size of the laser beam of the injection light needs to be larger than the size of the laser beam of the amplification stage light.

  18A and 18B show the relationship among the slit 320, the cross section 102 of the laser beam of the injection light, and the cross section 202 of the laser beam of the amplification stage light. FIG. 18A shows a state before the slit 320 rotates, and FIG. 18B shows a state after the slit 320 rotates. In the drawing, a portion indicated by a broken line is a cut-out portion of the laser beam section 102 of the injection light that overlaps the laser beam section 202 of the amplification stage light.

As shown in FIG. 18, by rotating the slit 320, the laser beam cross section 102 of the injection light can be artificially rotated around the injection optical axis.
As a result, as described with reference to FIG. 2, the relative rotation angle difference θ between the cross sections of both the injected light and the amplified stage light is eliminated, and high output and highly stable oscillation is realized.

The procedure of the adjustment method is the same as the procedure of the adjustment method of the first embodiment described above, and is performed as follows.

(Measurement step)
First, the beam profiler 401 measures the cross-sectional profile of the laser beam that is discharge-excited by the oscillation stage laser apparatus 100 and the cross-sectional profile of the laser beam that is discharge-excited by the amplification stage laser apparatus 200.

(Adjustment step)
Next, on the basis of the measurement result, the oscillation stage laser apparatus 100 eliminates the deviation between the cross section of the laser beam discharge-excited by the oscillation stage laser apparatus 100 and the cross section of the laser beam discharge-excited by the amplification stage laser apparatus 200. Adjustment for rotating the cross section of the laser beam excited by discharge around the optical axis is performed by the adjusting means 300 (the slit 320 and the rotation mechanism of the slit 320).

  The above has been described assuming the MOPO type two-stage laser device 1, but the configuration of the optical resonator of the two-stage laser device 1 is arbitrary. For example, as shown in FIG. 19, the present invention can be applied to a configuration in which a ring optical resonator is used in the amplification stage laser device 200.

  Hereinafter, portions common to the configuration shown in FIG. FIG. 19A is a side view of the two-stage laser device 1, and FIG. 19B is a top view of the two-stage laser device 1.

  As shown in FIG. 19, the band narrowing module 110 and the output coupling mirror 120 constitute an optical resonator of the oscillation stage laser device 100. The band narrowing module 110 includes a prism beam expander and a grating (diffraction grating). The grating dispersion direction, that is, the beam expanding direction by the prism beam expander is arranged in a direction perpendicular to the discharge direction of the discharge electrodes 131 and 132.

The laser beam transmitted through the output coupling mirror 120 is reflected by the high reflection mirror 11, enters the plano-convex cylindrical lens 301, and passes through the plano-convex cylindrical lens 301. The laser beam transmitted through the plano-convex cylindrical lens 301 is further incident on the plano-convex cylindrical lens 302 and is transmitted through the plano-convex cylindrical lens 302. The laser beam transmitted through the plano-convex cylindrical lens 302 is reflected by the high reflection mirror 12, further reflected by the high reflection mirror 13, and incident on the output coupling mirror 220 of the amplification stage laser device 200.

The output coupling mirror 220 and the high reflection mirrors 14, 15, and 16 constitute a ring optical resonator of the amplification stage laser device 200. In other words, the output coupling mirror 220 and the high reflection mirrors 14, 15, and 16 are arranged with their reflection surfaces inclined by 45 ° with respect to the longitudinal direction of the amplification stage chamber 201 when viewed from the upper surface of the amplification stage chamber 201 ( (Refer FIG.19 (b)). A beam profiler 401 is disposed at a position facing the amplification stage chamber 201 with the output coupling mirror 220 interposed therebetween.

The beam of injection light emitted from the oscillation stage laser device 100 and incident on the output coupling mirror 220 is transmitted through the output coupling mirror 220 and injected into the ring optical resonator of the amplification stage laser device 200. The beam of injected light that has passed through the output coupling mirror 220 is reflected by the high reflection mirror 14 and is injected into the discharge unit 203 between the discharge electrodes 231 and 232 of the amplification stage chamber 201 through the window 241. Since the injection light transmitted through the output coupling mirror 220 has beam divergence, it is reflected by the high reflection mirror 14 while spreading slightly, and is incident on the discharge part 203 between the discharge electrodes 231 and 232 of the amplification stage chamber 201 at an angle. . When the injection light is injected into the discharge unit 203 between the discharge electrodes 231 and 232 of the amplification stage chamber 201, the amplification stage laser device 200 starts discharge at the timing of introduction of the injection light. As long as the discharge continues in the amplification stage chamber 201, the light is amplified a plurality of times by the ring optical resonator, and the laser beam is finally emitted from the output coupling mirror 220 to the outside.

That is, the discharge light is discharged between the discharge electrodes 231 and 232 in synchronization with the injection light beam passing through the discharge part 203 between the discharge electrodes 231 and 232, and the injection light is amplified. The amplified beam of injected light is incident on the high reflection mirror 16 through the window 242. The amplified injection light beam reflected by the high reflection mirror 16 is incident on the high reflection mirror 15, reflected by the high reflection mirror 15, and folded toward the window 242 of the amplification stage chamber 201. The beam of amplified injection light is incident on the discharge part 203 between the discharge electrodes 231 and 232 at an angle and further amplified.

The amplified injected light that has passed through the discharge part 203 between the discharge electrodes 231 and 232 reaches the output coupling mirror 220 via the window 241. A part of the laser beam reaching the output coupling mirror 220 is reflected by the partial reflection surface of the output coupling mirror 220, further reflected by the high reflection mirror 14, and again passes through the discharge unit and is amplified. The amplified laser beam passes through the window 242 and is folded back by the high reflection mirrors 16 and 15, and again passes through the discharge portion and is amplified. Thus, the light repeats resonance a plurality of times between the high reflection mirrors 14, 15, 16 and the output coupling mirror 220, and a part of the light incident on the partial reflection surface of the output coupling mirror 220 passes through the output coupling mirror 220. The light is transmitted and emitted as output light from the amplification stage laser device 200 to the outside.

When the reflectance of the output coupling mirror 220 is 20 to 30%, the injection efficiency is 80% to 70%, and a high injection efficiency can be obtained.

In the two-stage laser apparatus 1 shown in FIG. 19, the laser light is folded back to the amplification stage chamber 201 using the high reflection mirrors 14, 15, and 16 inclined by 45 ° with respect to the longitudinal direction of the amplification stage chamber 201. However, the laser beam may be folded back to the amplification stage chamber 201 using Fresnel reflection by the total reflection prism.

In each of the above-described embodiments, the MOPO-type two-stage laser apparatus 1 has been described. However, the configuration of the MOPO-type two-stage laser apparatus 1 in each embodiment is the same as that of the MOPA-type two-stage laser apparatus. The present invention may be similarly carried out by substituting

FIG. 1 is a view showing an arrangement example of a MOPO type two-stage laser device, FIG. 1A is a side view of the two-stage laser device, and FIG. 1B is a top view of the two-stage laser device. It is. 2A is a diagram for explaining that there is a relative rotation angle difference between the cross section of the laser beam discharge-excited in the oscillation stage chamber and the cross section of the laser beam discharge-excited in the amplification stage chamber. FIGS. 2B and 2C are diagrams for explaining the influence of the relative rotation angle difference on the laser output variation and the laser output. FIG. 3 is a graph showing the relationship between the rotation angle of the injection light laser beam section relative to the reference angle and the variation in pulse energy. FIG. 4 is a graph showing the relationship between the rotation angle of the injection laser beam cross section relative to the reference angle and the pulse energy. FIG. 5 is a perspective view showing a configuration example of a MOPO-type two-stage laser apparatus, showing a configuration example of the first embodiment. FIGS. 6A and 6B are diagrams for explaining the principle that the injection light is rotated by the rotation of the plano-convex cylindrical lens. FIGS. 6A and 6B are perspective views seen from different angles. ) And (d) are views illustrating cross sections of the laser beam irradiated on the virtual screen shown in FIGS. 6 (a) and 6 (b), respectively. FIG. 7 is a flowchart showing the procedure of the adjustment method. FIGS. 8A to 8D are diagrams illustrating examples of the configuration of the rotation mechanism of the planoconvex cylindrical lens. FIGS. 9A, 9B, and 9C are diagrams showing a configuration example of a rotation actuator of a plano-convex cylindrical lens. 10A and 10B are diagrams showing an embodiment in which a cylindrical mirror and a cylindrical lens are used as adjusting means. FIG. 10A is a perspective view of the overall configuration, and FIG. 10B is an enlarged perspective view of the cylindrical mirror. is there. FIG. 11 is a perspective view showing a configuration example of a MOPO type two-stage laser apparatus, showing a configuration example of the second embodiment. FIG. 12 is a perspective view showing a configuration example of a MOPO type two-stage laser apparatus, showing a configuration example of the fifth embodiment. FIG. 13B is a diagram illustrating a configuration example of the rotation mechanism of the oscillation stage chamber, and FIG. 13A is a diagram illustrating a state in which the oscillation stage chamber is inclined with respect to the vertical axis. 14A, 14 </ b> B, and 14 </ b> C are perspective views illustrating other configuration examples of the rotation mechanism. FIG. 15 is a perspective view showing a configuration example of a MOPO type two-stage laser apparatus, showing a configuration example of the sixth embodiment. FIG. 16B is a diagram illustrating a configuration example of the rotation mechanism of the amplification stage chamber, and FIG. 16A is a diagram illustrating a state in which the amplification stage chamber is inclined with respect to the vertical axis. FIG. 17 is a perspective view showing a configuration example of a MOPO-type two-stage laser apparatus, showing a configuration example of the eighth embodiment. 18A and 18B are diagrams showing the relationship among the slit, the cross section of the laser beam of the injection light, and the cross section of the laser beam of the amplification stage light, and FIG. 18A shows the state before the slit rotation. FIG. 18B is a diagram illustrating a state after the slit is rotated. FIG. 19 is a diagram illustrating a configuration example of a two-stage laser apparatus using a ring optical resonator in the amplification stage laser apparatus, FIG. 19A is a side view of the two-stage laser apparatus, and FIG. It is a top view of a two-stage laser apparatus.

Explanation of symbols

1 2-stage laser apparatus, 100 oscillation stage laser apparatus, 200 amplification stage laser apparatus,
101 Oscillation stage chamber 201 amplification stage chamber 300 adjustment means 400 measurement means

Claims (6)

In a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
By rotating the cross section of the laser beam discharge-excited by the oscillation stage laser device and / or the cross section of the laser beam discharge-excited by the amplification stage laser apparatus around the optical axis, Adjusting means for matching the cross section and the cross section of the laser beam that is discharge-excited by the amplification stage laser device ;
A measuring means for measuring a cross-sectional profile of a laser beam discharge-excited by an oscillation stage laser apparatus and a cross-sectional profile of a laser beam discharged by an amplification stage laser apparatus;
Is provided,
Based on the measurement results of the measurement means, the adjustment means is manually adjusted so that there is no deviation between the cross section of the laser beam excited by the oscillation stage laser apparatus and the cross section of the laser beam excited by the amplification stage laser apparatus. Or be automatically controlled
A two-stage laser device. The adjusting means is a rotatable optical device provided on the optical axis between the oscillation stage laser device and the amplification stage laser device.
The two-stage laser apparatus according to claim 1. The adjusting means is means for rotating at least one of the oscillation stage laser apparatus and the amplification stage laser apparatus around the optical axis.
The two-stage laser apparatus according to claim 1 . Optical equipment should include plano-convex lenses
The two-stage laser apparatus according to claim 2 . An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
Measuring a cross-sectional profile of a laser beam discharge-excited by an oscillation stage laser device and a cross-sectional profile of a laser beam discharge-excited by an amplification stage laser device;
Based on the measurement result, the laser pumped by the oscillation stage laser apparatus so that there is no deviation between the cross section of the laser beam pumped by the oscillation stage laser apparatus and the section of the laser beam pumped by the amplification stage laser apparatus. An adjustment method applied to a two-stage laser apparatus, comprising: adjusting the cross section of the beam and / or adjusting the rotation of the cross section of the laser beam discharge-excited by the amplification stage laser apparatus around an optical axis. An adjustment method applied to a two-stage laser apparatus provided with an oscillation stage laser apparatus and an amplification stage laser apparatus,
The cross-sectional profile of the laser beam that is discharged and excited by the oscillation stage laser apparatus is measured while the operation of the amplification stage laser apparatus is stopped, and the discharge excitation is performed by the amplification stage laser apparatus while the operation of the oscillation stage laser apparatus is stopped. Measuring a cross-sectional profile of the laser beam to be produced;
Based on the measurement result, the laser pumped by the oscillation stage laser apparatus so that there is no deviation between the cross section of the laser beam pumped by the oscillation stage laser apparatus and the section of the laser beam pumped by the amplification stage laser apparatus. Adjusting the cross section of the beam or / and rotating the cross section of the laser beam discharge-excited by the amplification stage laser device around the optical axis;
And a step of operating the two-stage laser device after adjustment.

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