JPH06338644A - Laser oscillator - Google Patents

Abstract

PURPOSE:To provide a laser oscillator, such as an excimer laser oscillator or a YAG laser oscillator provided with an optical resonator, which is capable of obtaining directly a beam of a uniform intensity from the optical resonator by a simple constitution without using a complicated optical system, has a small number of constituent components and is easily adjusted. CONSTITUTION:A laser oscillator is one developed by devising the relation between the arrangement direction of a prism 21 and a totally reflecting mirror. With the prism 21 arranged on an optical path in a resonator 22, a vertical angle part 21A of this prism 21 is arranged on the side of a partially reflecting mirror 4 and a totally reflective film 23 is formed on a reflective surface 21B, which opposes to this vertical angle part 21A, of the prism 21 as a totally reflecting mirror means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator, and in particular, lasers such as an excimer laser oscillator and a YAG laser oscillator can be obtained by reducing the number of parts and obtaining a laser beam having a uniform beam intensity distribution in a beam cross section. It concerns oscillators.

[0002]

2. Description of the Related Art Generally, an excimer laser oscillator using a gas medium for an excimer laser as a laser medium has a shorter upper level lifetime of several nanoseconds and a higher amplification efficiency than other laser oscillators of different types. Mode oscillation tends to occur. Therefore, the beam cross-section intensity of the laser light emitted from the excimer laser oscillator is extremely nonuniform.

For example, a discharge excitation type excimer laser oscillator has a flat top intensity distribution in the electrode direction and a Gaussian-like intensity distribution in the direction perpendicular to the electrodes.

An outline will be given based on FIGS. 11 to 13.
FIG. 11 is a schematic perspective view of a general excimer laser oscillator 1. This excimer laser oscillator 1 includes a laser container 2, a total reflection mirror 3 (total reflection mirror means) provided before and after the laser container 2, and And an optical resonator 5 having a partial reflection mirror 4 (partial reflection mirror means).

The laser vessel 2 contains a pair of discharge electrodes 6 and a gas medium for laser oscillation, and plasma is generated by the discharge between the discharge electrodes 6 to generate an optical resonator 5.
Laser oscillation is performed by.

Each of the pair of discharge electrodes 6 has a cross section close to a semicircle suitable for uniform discharge,
During that time, a discharge state that is as uniform as possible is generated, and the length thereof is set to 2L.

As shown in the figure, the length direction parallel to the top surface 6A of the discharge electrode 6 is defined as the X axis (optical axis), and the length direction of the discharge electrode 6 is in the plane including the pair of discharge electrodes 6. The Y-axis is the direction passing through the center, and the lengthwise direction of the discharge electrode 6 (optical axis,
The direction perpendicular to the X axis) and the central direction (Y axis) is defined as the Z axis.

A portion of the top surface 6A between the discharge electrodes 6 has the best discharge state, and therefore the beam intensity of the emitted laser light is maximum from this portion. However, the actual beam intensity is measured outside the partial reflecting mirror 4, but for convenience of description, it will be described below based on the X axis, Y axis, and Z axis.

That is, as shown in FIG. 12, the beam intensity in the XY plane where Z = 0 (the beam intensity as seen from the X-axis direction when cut in the XY plane) is the maximum, and the positive and negative directions of Z from this point. The beam intensity gradually weakens as the position shifts (Gaussian-like intensity distribution).

Further, as shown in FIG. 13, the beam intensity in the YZ plane perpendicular to the X axis (the beam intensity seen from the X axis direction when cut in the YZ plane) is 2D between the top surfaces 6A of the discharge electrodes 6. Is the maximum, and the beam intensity gradually weakens (flat top intensity distribution) as it deviates in the positive and negative directions of Y from here.

Therefore, in applying the oscillated laser light to various applications, it is important to make the beam intensity distribution uniform, but the oscillation direction is perpendicular to the direction (inter-electrode direction and oscillation direction). Is the vertical direction;
There is a problem that it is difficult to obtain a uniform beam intensity distribution (or flat top intensity distribution) in the Z-axis direction.

Conventionally, in order to eliminate such nonuniformity of beam intensity, an optical system called a beam homogenizer has been installed outside the optical resonator 5 of the excimer laser oscillator 1.

This beam homogenizer combines a plurality of prisms, reflecting mirrors, lenses and the like, divides the beam into a plurality of beams, and then superimposes the plurality of beams again, and by the integration effect of the superposition. This is intended to make the beam intensity uniform. Such a homogenizer is disclosed in, for example, JP-A-2-323.

Further, as a method for making the beam intensity uniform by reducing the beam divergence angle, a devised structure of the optical resonator is shown in "Laser Research", October 1991, P966-969.

An excimer laser oscillator 10 having this structure shown in FIG. 14 is provided with an optical resonator 12 having a partial reflection mirror 4 and a prism 11 outside the laser container 2.

However, the conventional method has the following problems because the optical system 13 such as a beam homogenizer for uniformizing the beam intensity is provided outside the optical resonator 12 of the excimer laser oscillator 10.

That is, since the beams divided into a plurality of beams by the optical system 13 such as the beam homogenizer have different propagation directions, there is a problem that the divergence angle of the beams after superposition becomes large.

Further, when a plurality of divided beams are superposed, the range in which the beam intensity becomes uniform is narrow in the beam propagation direction, and there is a problem that a uniform intensity distribution is not provided before and after the range.

Furthermore, the more uniform the beam intensity is, the more the number of beam divisions must be increased.
There is a problem that the configuration of the optical system 13 such as a beam homogenizer becomes complicated and its adjustment is difficult.

Furthermore, since the optical system 13 having a complicated structure is installed outside the optical resonator 12, there is a problem that the beam propagation efficiency is lowered and the laser energy cannot be effectively used.

Further, in particular, in the excimer laser oscillator 10 shown in FIG. 14, the prism 11 that functions as a total reflection mirror is used.
Since it is composed of two triangular prisms, each surface facing the laser vessel 2 must be adjusted to a single plane, and its size must be adjusted to the width of the beam.

Further, there is a problem that adjustment is very difficult because the optical axis must coincide with the boundary between the two triangular prisms.

Note that this configuration is equivalent to a configuration in which two independent optical resonators are arranged side by side, and there is a problem that it is very difficult to make the beam intensity uniform over the entire beam.

In addition, in the general excimer laser oscillator, the total reflection mirror 3 and the partial reflection mirror 4 are used as the optical resonator 5.
The excimer laser oscillator 1 shown in FIG.
In the case of 0, the prism 11 is also required, the number of constituent parts including the excimer laser oscillator 10 is large, and the optical axis adjustment is complicated.

In addition, as described with reference to FIGS. 12 and 13, there is a problem that the beam profile depends on the distance between the total reflection mirror 3 and the prism.

As described above, the non-uniformity of the intensity distribution of the oscillation beam has the same problem in other laser oscillators using a solid as a laser medium. For example, YA
The G (yttrium aluminum garnet) laser oscillator will be described below.

FIG. 15 shows a conventional YAG laser oscillator 1.
4 is a schematic configuration diagram of FIG. 4, showing the YAG laser oscillator 1
4 has a YAG laser rod 15 and an optical resonator 18 having a total reflection mirror 16 (total reflection mirror means) and a partial reflection mirror 17 (partial reflection mirror means) provided in front of and behind the YAG laser rod 15, respectively.

The YAG laser oscillator 14 actually has various additives such as Nd-YAG (neodymium-yttrium aluminum garnet) or Er-YAG (erbium-yttrium aluminum garnet) as its laser medium. There are some types, and in addition to these, Nd-glass and the like are included.

As shown in FIG. 16, the shape of the oscillation beam of the YAG laser oscillator 14 has a Gaussian-like intensity distribution at any radial cross section about the optical axis. The center of the distance is strong and the periphery is weak.

Therefore, when a certain area of the workpiece is processed by using the oscillation beam of the YAG laser oscillator 14, the peripheral portion of the oscillation beam is removed or an optical system (not shown) is used to process the workpiece. There is a problem that it is necessary to make the beam portion corresponding to the portion uniform.

However, in such a YAG laser oscillator 14 and other laser oscillators (not shown),
There is no structure for arranging an optical component inside the optical resonator 18 to make the oscillation beam uniform.

As shown in FIG. 17, in the excimer laser oscillator 1, the pattern 1A in the plane perpendicular to the optical axis of the oscillating beam is rectangular, and in the YAG laser oscillator 14, the optical axis of the oscillating beam. The pattern 14A in the plane perpendicular to is circular.

[0033]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a beam having a uniform intensity can be directly obtained from an optical resonator with a simple structure without using a complicated optical system. It is an object of the present invention to provide a laser oscillator such as an excimer laser oscillator or a YAG laser oscillator that includes an optical resonator and that has a small number of constituent parts and is easy to adjust.

[0034]

That is, the present invention focuses on devising the direction in which prisms are arranged and the relationship with the total reflection mirror, and optical resonance provided with the total reflection mirror means and the partial reflection mirror means. And a laser medium provided between the optical resonators, wherein a prism is arranged on the optical path in the optical resonator, and the apex angle portion of the prism is the partial reflection mirror. Placed on the means side,
Further, the laser oscillator is characterized in that a total reflection film is formed as the total reflection mirror means on the reflection surface facing the apex angle portion.

The prism may have a pyramid shape or a cone shape. In the case of the excimer laser oscillator, either a pyramid shape or a cone shape can be adopted, and in the case of the YAG laser oscillator, the cone shape is desirable.

The prism can be arranged at right angles to the optical axis of the optical resonator.

In the prism, the total reflection film can be arranged at right angles to the optical axis of the optical resonator.

A prism moving mechanism for moving the prism along the optical path can be provided.

The present invention can be applied to an excimer laser oscillator by using the above laser medium as a gas medium for excimer laser.

The prism is perpendicular to the plane containing the pair of discharge electrodes located parallel to the optical axis between the optical resonators and perpendicular to the optical axis of the optical resonator. Can be placed.

The prism is perpendicular to the plane including the pair of discharge electrodes (the plane including the Y-axis direction) located parallel to the optical axis between the optical resonators (the X-axis direction).
And the total reflection film can be arranged at right angles (in the Z-axis direction) to the optical axis of the optical resonator.

The prism may be provided with a thickness in a direction parallel to the optical axis.

The present invention can be applied to a YAG laser oscillator by using the above laser medium as a YAG laser rod.

[0044]

In the laser oscillator according to the present invention, since the prism is arranged on the optical path in the optical resonator, it is possible to solve the above-mentioned problems caused by installing an optical system such as a beam homogenizer outside the optical resonator. At the same time, the beam intensity can be made uniform by the refraction of the laser light by the prism.

In the case of the excimer laser oscillator, the beam intensity in the direction perpendicular to the discharge electrode can be made uniform. Further, by providing the prism with a thickness in a direction parallel to the optical axis, total reflection of incident light by the prism can be facilitated.

In particular, since the total reflection film corresponding to the total reflection mirror means is formed on the reflection surface of the prism, the prism can also serve as the total reflection mirror means, and the number of constituent parts can be reduced. it can.

[0047]

EXAMPLE Next, an excimer laser oscillator 20 according to a first example in which the present invention is applied to an excimer laser oscillator.
Will be described with reference to FIGS. However, in the following description, the same parts as those in FIGS. 11 to 17 are designated by the same reference numerals, and the detailed description thereof will be omitted.

FIG. 1 is a schematic configuration diagram showing an excimer laser oscillator 20, and is a diagram viewed from the Y-axis direction described above based on FIG. This excimer laser oscillator 20
Has a laser container 2 and an optical resonator 22 having a prism 21 and a partial reflection mirror 4.

The prism 21 has an apex angle portion 21A arranged toward the partial reflecting mirror 4 side and a reflecting surface 21 perpendicular to the optical axis.
B and a slope 21C facing the reflection surface 21B at a predetermined angle.
And 21D and both side surfaces 21E parallel to the optical axis, for example, a prism (triangular prism) is provided, which is provided at a position separated from the laser container 2 by a predetermined distance.

As the predetermined distance, when the prism 21 is moved, the uniformity of the beam intensity changes, and therefore the position where the beam intensity is most uniform is shown.

Further, a total reflection film 23 as total reflection mirror means corresponding to the total reflection mirror 3 is provided on the reflection surface 21B.

The prism 21 is arranged in a plane parallel to the Z axis (perpendicular to the optical axis of the optical resonator 5) and on a plane including the discharge electrode 6 (XY plane). The reflecting surface 21B is oriented at a right angle to it.

Various shapes can be adopted as the shape of the prism in the present invention. For example, the prism 24 shown in FIG. 2 has an apex angle portion 24A, a reflecting surface 24B which is perpendicular to the optical axis and has a total reflection film 25 formed thereon, and a reflecting surface 24.
Slope 24C and slope 24D facing B at a predetermined angle
And a left side surface 24E and a right side surface 24F parallel to the optical axis,
It is a pentagonal prism having an upper surface 24G and a lower surface 24H parallel to the optical axis.

Further, the prism 26 shown in FIG. 3 has an apex angle portion 26A, a reflecting surface 26B which is perpendicular to the optical axis and has a total reflection film 27 formed thereon, and an inclined surface 26C which faces the reflecting surface 26B at a predetermined angle. Slope 26D, slope 26E and slope 26F, and left side surface 26G and right side surface 26 parallel to the optical axis.
It is a pentagonal prism having H and an upper surface 26I and a lower surface 26J parallel to the optical axis. The slope 26C, the slope 26D,
The slope 26E and the slope 26F form a quadrangular pyramid.

The operation of the excimer laser oscillator 20 will be described below with reference to FIG. The beam emitted from the laser container 2 is incident on the prism 21. The incident beam is deflected by the prism 21 in two directions. That is, the upper beam is deflected downward and the lower beam is deflected upward with respect to the optical axis.

The deflected light is reflected by the total reflection film 23,
The beam is deflected again by the prism 21 and emitted as a beam parallel to the optical axis through the partial reflecting mirror 4.

More specifically, the deflected beam will be described. For example, the beam generated at the point P1 far from the optical axis and the beam generated at the point Q1 near the optical axis are close to the optical axis by the prism 21 and the total reflection film 23, respectively. It will pass through the point P2 and the point Q2 far from the optical axis.

That is, in the arrangement posture of the illustrated prism, that is, in the Z-axis direction, the beam generated at the central portion with respect to the optical axis moves to the outer peripheral portion, and the beam generated at the outer peripheral portion moves to the central portion.

Such a movement is repeatedly performed between the partial reflection mirror 4 and the total reflection film 23 to perform a kind of superposition, and a part thereof becomes an outgoing beam. This beam has a uniform beam intensity due to the superposition of laser beams in the Z-axis direction.

Thus, the prism 21 (the prism 21
Since the total reflection film 23 of (1) fulfills the function of the conventional total reflection mirror 3, the optical resonator 22 is composed of only the partial reflection mirror 4 and the prism 21, and the beams are superposed by the refraction of the prism 21. A beam having a uniform intensity distribution can be obtained directly from the optical resonator 22.

The prism 21 has a flat surface on all of its surfaces. For example, the prism 24 shown in FIG.
24C and 24D of the prism are curved surfaces such as spherical surfaces or aspherical surfaces other than flat surfaces, and the slopes 26C, 26D, 26E and 26F of the prism 26 shown in FIG. 3 are spherical surfaces or flat surfaces. It is also possible to use a lens having a curved surface such as an aspherical surface.

For example, FIG. 5 shows still another example of the prism according to the present invention, in which the prism is a conical prism 28.

The prism 28 shown in FIG. 5 has an apex portion 28A.
A reflecting surface 28B that is perpendicular to the optical axis and has a total reflection film 29 formed thereon, a conical sloped surface 28C that faces the reflecting surface 28B at a predetermined angle, and a circumferential surface 28D that is parallel to the optical axis.
Have.

If such a conical prism 28 is used, the plane on which the beam intensity is made uniform is the prism 2 described above.
The beam intensity can be made uniform in the Z-axis direction without depending on the number of slopes as in 1, 24, and 26, and in the directions around the X-axis (optical axis),
That is, by overlapping the laser beams in all directions of 360 degrees around the optical axis, it is possible to achieve uniformity in all directions.

Therefore, the discharge state becomes non-uniform due to dust on the discharge electrode 6 or a slight deviation thereof, or distortion of each component due to heat generation by laser oscillation, and the non-uniformity of the beam intensity due to the discharge state. Even if it occurs, it becomes possible to properly make it uniform.

The cone-shaped prism 28 is easier to perform the positioning adjustment operation than the pyramidal prisms 21, 24 and 26, but in the excimer laser oscillator, as shown in FIG. 17, it is perpendicular to the optical axis of the oscillation beam. In-plane pattern 1
Since A has a rectangular shape, a larger cross-sectional area surrounding the pattern 1A is required.
Reference numerals 4 and 26 are smaller prisms that can make the beam uniform.

The pentagonal prism 24 shown in FIG.
24G and the lower surface 24H parallel to the optical axis of the left side surface 26 parallel to the optical axis of the pentagonal prism 26 shown in FIG.
G, the right side surface 26H, the upper surface 26I and the lower surface 26J, and the thickness in the direction parallel to the optical axis as represented by the circumferential surface 28D parallel to the optical axis of the conical prism 28 shown in FIG. By providing the, it is possible to facilitate total reflection of incident light by the prisms (total reflection films 25, 27, 29).

Next, FIG. 6 shows an excimer laser oscillator 30 according to a second embodiment of the present invention, in which the prism 21 is attached to a prism moving mechanism 31.

The prism moving mechanism 31 includes a uniaxial stage fixing portion 32, a uniaxial stage moving portion 33, a holder fixing portion 34, a prism moving portion 35, and an inclination adjusting screw 36.
Have and.

The uniaxial stage movable portion 33 is attached to the uniaxial stage fixing portion 32 so as to be movable along the optical path, and the holder fixing portion 34 is fixed on the uniaxial stage movable portion 33.

The prism movable portion 35 is the holder fixing portion 34.
This is attached to the lens so that it can move in the direction perpendicular to the optical path.

The prism 21 is held on the prism movable portion 35, and the tilt adjusting screw 36 is adjusted to make the optical axis of the prism 21 parallel to the laser light.

One of the important factors in the present invention is the distance between the partial reflection mirror 4 and the total reflection film 23 sandwiching the prism 21. That is, the beam intensity when the beams are superposed is governed by the distance between the total reflection film 23 and the partial reflection mirror 4.

Therefore, when a uniform beam is required, the uniaxial stage movable part 33 described above is moved,
The distance between the total reflection film 23 and the partial reflection mirror 4 is set to a predetermined distance.

When a beam having a uniform distribution is not required, the uniaxial stage movable part 33 with respect to the total reflection film 23.
A beam having an arbitrary beam width can be obtained by moving.

If a deviation of the optical axis due to mechanical rattling or the like occurs as the prism 21 moves, the tilt adjusting screw 36 can be used to adjust the deviation.

In the above embodiment, the laser container 2
The so-called external resonator type in which the optical resonator 22 is provided outside the above is described, but the same applies to the internal resonator type in which the optical resonator 22 is provided inside the laser container 2.

Next, FIG. 7 shows a YAG laser oscillator 40 according to a third embodiment in which the present invention is applied to a YAG laser oscillator.
AG laser rod 15, optical resonator 18 having total reflection mirror 16 and partial reflection mirror 17, total reflection mirror 16 and YA
And a conical prism 41 arranged between the G laser rod 15 and the G laser rod 15.

The conical prism 41 has an apex angle portion 41A.
And a bottom surface 41B perpendicular to the optical axis and a conical slope surface 41C facing the bottom surface 41B at a predetermined angle.

The operation of the YAG laser oscillator 40 will be described below with reference to FIG. The beam emitted from the YAG laser rod 15 is incident on the prism 41. The incident beam is deflected by the prism 41 in two directions. That is, the upper beam is deflected downward and the lower beam is deflected upward with respect to the optical axis.

The deflected light is reflected by the total reflection mirror 16,
The beam is deflected again by the prism 41 and emitted as a beam parallel to the optical axis through the partial reflection mirror 17.

More specifically, the deflected beam is, for example, a beam generated at a point P1 far from the optical axis and a beam generated at a point Q1 near the optical axis, which are close to the optical axis by the prism 41 and the total reflection mirror 16, respectively. It will pass through the point P2 and the point Q2 far from the optical axis.

That is, in the illustrated arrangement of the prisms, that is, the beam generated at the center with respect to the optical axis moves to the outer peripheral portion, and the beam generated at the outer peripheral portion moves to the central portion.

Such a movement is repeated between the partial reflecting mirror 17 and the optical resonator 18 to perform a kind of superposition, and a part thereof becomes an outgoing beam. This beam has a uniform beam intensity due to the superposition of the laser beams.

Thus, the beams having a uniform intensity distribution can be directly obtained from the optical resonator 18 by superimposing the beams by the refraction effect of the prism 41.

Uniform processing can be performed by using a simple enlargement / reduction optical system (not shown) for the oscillation beam.

Next, FIG. 9 shows a YAG laser oscillator 50 according to a fourth embodiment of the present invention. The YAG laser oscillator 50 includes a YAG laser rod 15, a conical prism 51 and a partial reflecting mirror 17. And the optical resonator 52.

The prism 51 has an apex angle portion 51A arranged toward the partial reflection mirror 17 side, a reflection surface 51B which is perpendicular to the optical axis and has a total reflection film 53 formed thereon, and a reflection surface 51B.
Has a conical slope 51C facing each other at a predetermined angle,
This is provided at a position separated from the YAG laser rod 15 by a predetermined distance.

As the predetermined distance, when the prism 51 is moved, the uniformity of the beam intensity changes, and therefore the position where the beam intensity is most uniform is shown.

The operation of the YAG laser oscillator 50 will be described below with reference to FIG. The beam emitted from the YAG laser rod 15 is incident on the prism 51. The incident beam is deflected by the prism 51 in two directions. That is, the upper beam is deflected downward and the lower beam is deflected upward with respect to the optical axis.

The deflected light is reflected by the total reflection film 53,
The beam is deflected again by the prism 51 and emitted as a beam parallel to the optical axis through the partial reflecting mirror 17.

More specifically, the deflected beam is, for example, a beam generated at a point P1 far from the optical axis and a beam generated at a point Q1 near the optical axis, which are close to the optical axis by the prism 51 and the total reflection film 53, respectively. It will pass through the point P2 and the point Q2 far from the optical axis.

That is, in the arrangement posture of the illustrated prism, that is, the beam generated at the central portion with respect to the optical axis moves to the outer peripheral portion, and the beam generated at the outer peripheral portion moves to the central portion.

Such a movement is repeated between the partial reflecting mirror 17 and the prism 51, a kind of superposition is performed, and a part thereof becomes an outgoing beam. This beam has a uniform beam intensity due to the superposition of the laser beams.

Thus, by superimposing the beams by the refraction action of the prism 51, a beam having a uniform intensity distribution can be obtained directly from the optical resonator 52.

Although all the surfaces of the prisms 41 and 51 are formed by planes, for example, a lens in which the conical slopes 41C and 51C are curved surfaces such as spherical surfaces or aspherical surfaces other than flat surfaces is used. You can also do it.

Further, the YAG laser oscillators 40, 50
In this case, since the oscillating beam pattern 14A is circular as shown in FIG. 17, the conical prism 4
By using Nos. 1 and 51, it is possible to superimpose the laser beams in all directions of 360 degrees around the optical axis, achieve homogenization in all directions, and obtain circular uniform light.

Incidentally, the above-mentioned prisms 21, 24, 26,
It is preferable to apply a non-reflective coating to the beam passage surfaces of 28, 41 and 51.

Further, although the embodiment in which the laser oscillator according to the present invention is applied to the excimer laser oscillator and the YAG laser oscillator has been described, it can be applied to various other laser oscillators.

[0100]

As described above, according to the present invention, the prism is provided with the total reflection film corresponding to the total reflection mirror means of the optical resonator of the laser oscillator such as the excimer laser oscillator or the YAG laser oscillator. The beam intensity of the beam emitted from the oscillator can be made uniform, and the number of constituent parts can be reduced to provide a simple and easily adjustable configuration.

[0101]

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an excimer laser oscillator 20 according to a first embodiment in which the present invention is applied to an excimer laser oscillator.

FIG. 2 is a front view and a left side view showing an example (prism 24) of a modification of the prism.

3A and 3B are a front view and a left side view showing another modification of the prism (prism 26).

FIG. 4 is a schematic configuration diagram for explaining the operation of the excimer laser oscillator 20.

FIG. 5 is a front view and a left side view showing still another example (conical prism 28) of deformation of the prism.

FIG. 6 is a schematic configuration diagram showing an excimer laser oscillator 30 according to a second embodiment of the present invention.

FIG. 7: Third application of the present invention to a YAG laser oscillator
3 is a schematic configuration diagram of a YAG laser oscillator 40 according to the example of FIG.

FIG. 8 is a schematic configuration diagram for explaining the operation of the YAG laser oscillator 40.

FIG. 9 is a schematic configuration diagram of a YAG laser oscillator 50 according to a fourth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram for explaining the operation of the YAG laser oscillator 50.

FIG. 11 is a schematic perspective view of a conventional excimer laser oscillator 1.

FIG. 12 is a graph of beam intensity on the XY plane in the Z-axis direction.

FIG. 13 is a graph of beam intensity on the YZ plane in the X-axis direction.

FIG. 14 is a configuration diagram of a conventional excimer laser oscillator 1 capable of making the beam intensity of an outgoing beam uniform.

FIG. 15 is a schematic configuration diagram of a conventional YAG laser oscillator 14.

FIG. 16 is a graph of the beam intensity of the oscillation beam of the YAG laser oscillator 14 of the same.

17 is a pattern 1A and Y in the plane perpendicular to the optical axis of the oscillation beam in the excimer laser oscillator 1. FIG.
It is explanatory drawing which shows the pattern 14A in a surface perpendicular | vertical to the optical axis of the oscillation beam in AG laser oscillator 14. FIG.

[Explanation of symbols]

1 Excimer Laser Oscillator 1A Pattern (rectangular) in a plane perpendicular to the optical axis of an oscillation beam by the excimer laser oscillator 1 Laser container 3 Total reflection mirror (total reflection mirror means) 4 Partial reflection mirror (partial reflection mirror means) 5 Optical resonator 6 Pair of discharge electrodes 6A Top surface of pair of discharge electrodes 6 Excimer laser oscillator 11 Prism 12 Optical resonator 13 Optical system such as beam homogenizer 14 YAG (yttrium aluminum garnet) laser oscillator 14A YAG laser oscillator 14 Pattern in a plane perpendicular to the optical axis of the oscillating beam (circular) 15 YAG laser rod 16 Total reflection mirror (total reflection mirror means) 17 Partial reflection mirror (partial reflection mirror means) 18 Optical resonator 20 Excimer laser oscillator 21 Prism 21A Vertical angle 21B of prism 21B Vertical to optical axis The reflecting surfaces 21C and 21D of the prism 21 are inclined surfaces facing the reflecting surface 21B at a predetermined angle 21E Both sides parallel to the optical axis 22 Optical resonator 23 Total reflection film formed on the reflecting surface 21B 24 Pyramidal prism 24A Top Corner 24B Reflecting surface 24C, 24D perpendicular to the optical axis 24C, 24D Slopes facing the reflecting surface 24B at a predetermined angle 24E, 24F Left and right surfaces parallel to the optical axis 24G, 24H Upper and lower surfaces parallel to the optical axis 25 Reflection Total reflection film formed on surface 24B 26 Pyramidal prism 26A Apex angle portion 26B Reflection surface perpendicular to the optical axis 26C, 26D, 26E, 26F Slopes facing the reflection surface 26B at a predetermined angle 26G, 26H Parallel to the optical axis Left side surface and right side surface 26I, 26J Upper surface and lower surface parallel to optical axis 27 Total reflection film formed on reflecting surface 26B 28 Conical prism 28A Apex angle portion 28B Reflecting surface perpendicular to the optical axis 28C Conical inclined surface facing the reflecting surface 28B at a predetermined angle 28D Circular surface parallel to the optical axis 29 Total reflection film formed on the reflecting surface 28B 30 Excimer laser oscillator 31 Prism moving mechanism 32 Uniaxial stage fixed part 33 Uniaxial stage movable part 34 Holder fixed part 35 Prism movable part 36 Tilt adjusting screw 40 YAG laser oscillator 41 Conical prism 41A Vertical angle part 41B Bottom face perpendicular to optical axis 41C Predetermined on bottom face 41B Conical slopes facing each other at an angle of 50 YAG laser oscillator 51 Conical prism 51A Vertical angle portion 51B Reflecting surface perpendicular to the optical axis 51C Conical slope facing the reflecting surface 51B at a predetermined angle 52 Optical resonator 53 Total reflection film 2L Length of discharge electrode 6 2D Distance between top surfaces 6A of discharge electrode 6 P1, Q2 Optical axis Point far from P2, Q1 Point near optical axis

Claims (11)

[Claims] 1. A laser oscillator comprising: an optical resonator provided with a total reflection mirror means and a partial reflection mirror means; and a laser medium provided between the optical resonators. A prism is disposed on the road, the apex angle portion of the prism is disposed on the side of the partial reflection mirror means, and a total reflection film is formed as the total reflection mirror means on the reflection surface facing the apex angle portion. Laser oscillator characterized by. 2. The laser oscillator according to claim 1, wherein the prism has a pyramid shape. 3. The laser oscillator according to claim 1, wherein the prism has a conical shape. 4. The laser oscillator according to claim 1, wherein the prism is arranged at right angles to the optical axis of the optical resonator. 5. The laser oscillator according to claim 1, wherein the prism has the total reflection film arranged at right angles to an optical axis of the optical resonator. 6. The laser oscillator according to claim 1, further comprising a prism moving mechanism that moves the prism along the optical path. 7. The laser oscillator according to claim 1, wherein the laser medium is a gas medium for an excimer laser. 8. The prism is perpendicular to a plane including a pair of discharge electrodes located parallel to the optical axis between the optical resonators and perpendicular to the optical axis of the optical resonator. The laser oscillator according to claim 7, wherein the laser oscillator is arranged in 9. The prism is perpendicular to a plane including a pair of discharge electrodes located parallel to the optical axis between the optical resonators and perpendicular to the optical axis of the optical resonator. 8. The total reflection film is arranged on the substrate.
The laser oscillator described. 10. The laser oscillator according to claim 7, wherein the prism is provided with a thickness in a direction parallel to the optical axis. 11. The laser medium is YAG
The laser oscillator according to claim 1, wherein the laser oscillator is a laser rod.