JPH0387083A - Laser equipment - Google Patents

Abstract

PURPOSE:To reduce the bias of light pumping, uniformize the light radiated from medium, and increase irradiation light energy, by constituting a light converging body of a member having a reflecting surface formed by using partial cylindrical surfaces and partial plane surfaces which surround uniformly a columnar type laser medium and a columnar type pumping light source, in an axially parallel symmetrical manner. CONSTITUTION:The title equipment is constituted of the following; a laser rod 12 composed of an axially symmetrical columnar type laser medium, a cylindrical type pumping lamp 11 arranged so as to be adjacent and parallel with the rod, and a light converging body 10 having a reflecting surface formed by using two partial cylindrical surfaces and two partial plane surfaces surrounding practically uniformly the rod and the lamp in an axially parallel symmetrical manner. In this constitution, central lines 21, 22 of the partial cylindrical surfaces, the axial center 32 of the rod 12, and the axial center 31 of the lamp 11 are arranged on the same plane; the axial center of the rod 12 facing the partial cylindrical surface is positioned on the center line 22 of the curved surface; the axial center 31 of the lamp 11 is shifted at a position nearer to the curved surface than the center line 21, on a plane l connecting the center lines 21, 22. Thereby the difference in the light intensity distribution is set within the range of about 20%, and uniform irradiation can be obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a laser device, and more particularly, one or more axially symmetrical columnar laser media, and one or more columnar excitation light sources arranged parallel to each other adjacent to the laser medium. and a light condenser having a reflective surface formed by two partial cylindrical curved surfaces and two or more partial flat surfaces, which substantially uniformly surrounds the laser medium and the excitation light source in translational symmetry in their axial directions. This invention relates to an improvement of a laser device consisting of the following.

[Conventional technology]

Laser light differs from general natural radiation light in that it has various characteristics such as being coherent and having excellent monochromaticity. Because of these characteristics, laser light is widely applied to high-precision, high-sensitivity measurements, metrology, research on nonlinear optics, optical communications, and the like. As a laser device for oscillating or amplifying such laser light, for example, Walt13r KOeCh
ner: 5olid-8tate La5er En
gineering, p, 301-306 (Spr.
inger Verlag, 1976) and Japanese Patent Application Publication No. 5
1-40894, as shown in FIG.
The most widely used type of device is a device in which a laser (medium) rod 12 and an excitation lamp 11 are placed in the center. This arrangement is based on a geometrical theorem, and in this type, which has a high light condensing property, the one in which the laser rod 12 and the excitation lamp 11 are arranged closely has the highest efficiency. Also, Japanese Patent Application Publication No. 1973-
As shown in FIG. 22, the 85291 has two excitation lamps 11.13 arranged on both sides of the laser rod 12, and as shown in FIG. An arrangement of laser rods 12, 14 is disclosed. However, in any case, the focus of the ellipse 41.42
．． 43.44 Excitation lamp 11.13 and laser rod 1
2.14, the intensity of the light from the excitation lamp becomes extremely high near the axis of the laser rod, and when the laser beam is oscillated or amplified, the destruction limit of the optical element is reached and the beam as a whole This had the problem that large output energy could not be obtained. Furthermore, there are parts of the laser rod that are not illuminated by the excitation lamp light.
Another problem was that the output of the beam as a whole was reduced. Eliminates the above-mentioned problems and suppresses the occurrence of parts of the laser rod that are not illuminated by the excitation lamp light, which is caused by arranging the axes of the excitation lamp and laser rod at the two focal points of the elliptical cylinder. However, a laser oscillation device capable of reducing excitation debris is disclosed in Japanese Patent Laid-Open No. 62-1 & 3193. In this device, as shown in FIG. 24, the axis 31 of the excitation light source 11 is located at one focal point 41 of a condenser 10 made of an elliptical cylinder, and the point within the laser rod 12 is located at the other focal point 42. According to this device, in which the axis 32 of the laser rod 12 is arranged so as to be shifted between the two focal points 41 and 42,
Although the intensity distribution of the light from the laser rod is also improved, the degree of uniformity of the distribution is insufficient, and there is a problem in that the position of maximum intensity is simply shifted from the axis of the laser rod. The above-mentioned document by W. Koechner also discloses a non-focal type laser device in which the cross section of the condenser is circular, arc-straight, or oval. This type of device in which the laser rod and excitation lamp are closely coupled is easy to manufacture and provides improved laser intensity distribution. However, it has a problem of lower efficiency than an elliptical cylinder type device. Furthermore, although the distribution of laser intensity is improved compared to the elliptical cylinder type, there is also the problem that it is still not sufficient. Furthermore, the above-mentioned W. Koechner literature and JP-A-62
-262480 also discloses a multiple coupling type laser device provided with a plurality of excitation light sources. Such a multiple coupling type improves the uniformity of the laser intensity in the Rondo cross section than a single light source. However, there are problems in that the S precepts become complicated and the device becomes large, so it is not suitable for some applications. The present invention has been made in view of the problems of the prior art as described above, and its object is to maintain a high degree of uniformity in the intensity distribution of light emitted from a laser medium, and to efficiently optically excite the laser medium. The object of the present invention is to provide a laser device that can be miniaturized.

[Means to solve the problem]

The present invention provides a laser device including one or more axially symmetrical columnar laser media, one or more columnar excitation light sources arranged parallel to each other and adjacent to the laser medium; two partially cylindrical curved surfaces substantially uniformly surrounding the laser medium and the excitation light source in translational symmetry in their axial directions;
a light condenser having a reflective surface formed by one or more partial planes, and the center line of the partial cylindrical curved surface, the axis of the laser medium, and the axis of the excitation light source are in the same plane. and the axis of at least one of two laser media, one laser medium and one excitation light source, or two excitation light sources that are opposite to the partially cylindrical curved surface of the reflective surface,
The above object is achieved by shifting the position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. The present invention also provides a laser device including a columnar excitation light source, four columnar laser media surrounding the excitation light source and arranged in parallel to each other, and a combination of the laser medium and the excitation light source. and a light condenser having a reflective surface formed by four partial cylindrical curved surfaces or four partial cylindrical curved surfaces and four or more partial planes substantially uniformly surrounding translationally symmetrical in the axial direction, and the excitation The axis of the light source is aligned with the intersection line of two orthogonal planes, and the center line of the two partial cylindrical curved surfaces and the axes of the two laser media facing the partial cylindrical curved surfaces are aligned with the two orthogonal planes. The center lines of the two partial cylindrical curved surfaces of the pond and the axes of the two laser media of the pond facing those partial cylindrical curved surfaces are within one plane forming the two orthogonal planes. Shifting the axis of at least one of the four laser media that is in a plane and faces the partial cylindrical curved surface of the reflective surface to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. Thus, the above-mentioned problem has been achieved. The present invention also provides a laser device including one columnar laser medium and four columns arranged parallel to each other surrounding the laser medium.
four columnar excitation light sources, four partial cylindrical curved surfaces or four partial cylindrical curved surfaces and four or more portions that substantially uniformly surround the laser medium and the excitation light source in translational symmetry in their axial directions; and a condenser having a reflective surface formed from a flat surface, the axis of the laser medium being aligned with the intersection line of two orthogonal planes, and the center line of two partial cylindrical curved surfaces and the partial cylindrical curved surfaces thereof. The axes of the two excitation light sources facing each other are within a plane forming the two orthogonal planes,
The center lines of the other two partial cylindrical curved surfaces and the axes of the other two excitation light sources facing the partial cylindrical curved surfaces are within another plane forming the two orthogonal planes, and the reflecting surface The above object is achieved by shifting the axis of at least one of the four excitation light sources facing the partial cylindrical curved surface to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. It is.

[Action and effect]

In the laser device according to the present invention, a reflecting surface formed of a partial cylindrical curved surface and a partial plane, which substantially uniformly surrounds the columnar laser medium and the columnar excitation light source in translational symmetry in their axial directions, is used as the condenser. As a result, the strong light-gathering property of an elliptical cylinder is alleviated, and the light from the excitation light source uniformly irradiates and excites the laser medium over a wide range, reducing the polarization of the optical excitation of the laser medium. can be reduced and the light emitted from the laser medium can be made uniform. Furthermore, the axis of the excitation light source and/or the laser medium is shifted to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface, so that the light irradiated from the excitation light source to the laser medium is More energy, more efficiency. As a result, a laser beam with a highly uniform intensity distribution is emitted, making it possible to increase the light intensity of most of the beam diameter to the destructive limit of the optical element and increase the output energy. . Further, the laser device can be made smaller, and the structure of the condenser is simple and the manufacturing cost is low. Therefore, it is possible to increase the laser output, reduce the size of the laser device, and reduce the price of the laser device, which has the advantage of expanding the industrial applications of laser light.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing the configuration of the first embodiment. This first embodiment includes a laser rod 12 made of one axially symmetrical columnar laser medium, one cylindrical excitation lamp 11 arranged parallel to each other adjacent to the laser rod 12, Consisting of a condenser 10 having a reflecting surface formed by two partially cylindrical curved surfaces and two partially flat surfaces, which substantially uniformly surrounds the laser rod 12 and the excitation lamp 11 in translational symmetry in their axial directions. The center lines 21 and 22 of the partially cylindrical curved surface, the axis 32 of the laser rod 12, and the axis 31 of the excitation lamp 11 are in the same plane, and are relative to the partially cylindrical curved surface of the reflecting surface. The axial center 32 of the laser rod 12 is located on the center [22] of the partially cylindrical curved surface, and the axial center 32 of the excitation lamp 11
1 is shifted to a position closer to the partial cylindrical curved surface than the center line 21 of the partial cylindrical curved surface on the plane °C connecting the center lines 21 and 22. With this arrangement, the excitation light reflected by the mirror surface of the condenser 10 widely excites the surface of the laser rod 12, and the intensity distribution of the light emitted from the laser rod 12 becomes
As shown in characteristic curve C in the figure, the curve is gentle. That is, in FIG. 2, characteristic curve A relates to the conventional laser device disclosed in Japanese Patent Laid-Open No. 51-40894 (see FIG. 21), where the distribution of light intensity is 65%.
There are varying degrees of height. Further, as shown in FIG. 3, characteristic curve B relates to a comparative example in which the cross-sectional shape of the condenser 10 is not an ellipse but a circle and a straight line, and the height difference in the light intensity distribution is about 20%. It has been improved. However, the total amount of optical energy of the laser beam emitted from the comparative example shown in FIG. 3 is reduced by about 40% compared to the conventional example shown in FIG. 21. In contrast, in the case of the first embodiment of the present invention, the light intensity distribution has only a height difference of about 20%, and the uniformity is greatly improved. Furthermore, the total amount of optical energy of the laser beam emitted from the laser device of this embodiment is approximately 15% higher than that of the comparative example shown in FIG. In this way, in this embodiment, not only the distribution of light intensity is improved, but also the total amount of light energy is improved, resulting in high efficiency. The inventors considered the reason for obtaining such high efficiency as follows. That is, in the comparative example shown in FIG.
Of the light emitted from the excitation rung 11, all the light emitted to the left of the perpendicular line A returns to the excitation lamp 11 again and does not contribute to the absorption of the laser rod 12. In contrast, in the first embodiment As shown in FIG.
)1! 1), the light that had returned to the excitation lamp 11 in the comparative example of FIG. 3 is absorbed by the laser rod 12 again, as shown at 4A and 4B in FIG. Therefore, in this example, there is no waste of light energy compared to the comparative example, and as a result, higher efficiency of the total amount of light energy is achieved than in the comparative example. When the light emitted from the excitation lamp 11 returns to the excitation lamp 11 again, the returned light is absorbed again by the plasma within the excitation lamp. Therefore, the plasma temperature inside the excitation lamp increases, and the emission spectrum of the excitation lamp 11 changes from the light concentrator 1.
Compared to the case where there is no 0, the position leaks to the shorter wavelength side and deviates from the optical absorption band of the laser rod 12. Therefore, compared to the comparative example shown in FIG. 3, the arrangement in the first embodiment is more suitable. , This is also considered to contribute to the high efficiency of the total amount of light energy. Furthermore, in the first embodiment, the axis 3 of the excitation lamp 11
By moving R 1 outwardly from the center line 21 of one of the partial cylindrical curved surfaces of the light condenser 10, the centers R21 and 22 of the partial cylindrical curved surfaces of the light condenser 10 can be brought closer to each other by the amount of movement. It becomes possible. Therefore, compared to the comparative example shown in FIG. 3, the condenser 10, and therefore the laser device, can be downsized by (R2-R+). Note that when the distance from the end of the condenser 10 to the axis 31 of the excitation lamp 11 is R1, and the radius of the condenser 10 is R2, as shown in FIG. 1, R1 is R+ = 1 /
It has been confirmed that the most efficient and desirable state is achieved at or near the point 2.R2. R+ = 1/2・
In the vicinity of the point R2, it is preferable that the line R1 = 1/2 · R2 is at least in the inside of the excitation lamp 11. In addition, the present invention is directed to the point R1 = 1/2R2 or in the vicinity thereof. It is not limited. FIG. 4 is a sectional view showing the configuration of a second embodiment of the present invention. In this second embodiment, in a laser device similar to the first embodiment, the axis 31 of the excitation lamp 11 is
are placed on the center line 21 of the partially cylindrical curved surfaces facing each other,
On the other hand, the axis 32 of the laser rod 12 is placed at a position closer to the partial cylindrical curved surface than the center line 22 of the partial cylindrical curved surface that the laser rod 12 is facing on the plane °C connecting the center lines 21 and 22. It has been shifted and placed. Other configurations and effects are the same as those in the first embodiment, so detailed explanations will be omitted. FIG. 5 is a sectional view showing the configuration of a third embodiment of the present invention. In the third embodiment, in a laser device similar to the first embodiment, not only the axis 31 of the excitation lamp 11 but also the axis 32 of the laser rod 12 are arranged on one partial cylindrical curved surface surrounding the laser rod 12. It is arranged so that it is located on the extension of the plane connecting the center line 22 and the center line 21 of the other partial cylindrical curved surface surrounding the excitation lamp 11. With this arrangement, the mirror surface of the condenser IO The excitation light that is reflected and directed toward the laser rod 12 spreads over a wide range, and the unevenness of the excitation of the laser rod 12 is reduced.In other words, the intensity distribution of the light emitted from the laser rod 12 is as follows:
The characteristic curve is as shown in FIG. In this characteristic curve, the height difference in the light intensity distribution is 25%, and the uniformity of the light intensity is slightly worse than in the first embodiment (about 20%). However, the total amount of light energy is increased by about 25% compared to the comparative example shown in FIG. This third embodiment is furthermore 2X(
R2R1) is smaller in size. In the third embodiment, the axis 31 of the excitation lamp 11 and the axis 32 of the laser rod 12 are connected from the end of the condenser 10.
R1 and R3 are the distances to R1 and R3, respectively, and R2 is the radius of the cylindrical portion of the condenser IO.As shown in FIG. - It was confirmed that the most efficient and desirable state is achieved at or near the point R2. That is, by adopting such a configuration, a laser device having a simple structure, low manufacturing cost, and excellent light focusing ability can be realized. However, in the present invention, R1=1/2・R2, R3=1/2
- It is not limited to the point R2 or the vicinity thereof. FIG. 6 is a sectional view showing the configuration of a fourth embodiment of the present invention. In this fourth embodiment, in a laser device similar to the first embodiment, a center line 21 of a partial cylinder surrounding the excitation lamp 11 and a partial cylinder surrounding the laser rod 12 are added to the plane constituting the condenser 10. Approximately 20
With this arrangement, the amount of excitation light reflected by the mirror surface of the condenser 10 and directed toward the laser rod 12 increases, and the intensity distribution of the light emitted from the laser rod 12 is , as shown in the characteristic curve E in Figure 2.This characteristic curve E shows that the difference in height of the light intensity distribution is improved to about 25%, but the total amount of light energy is compared to the comparative example in Figure 3. This has increased by about 30%.Although this example is an improvement over the first example,
The invention is not limited to this, and the second and third embodiments may be similarly improved. FIG. 7 is a sectional view showing the configuration of a fifth embodiment of the present invention. This fifth embodiment uses a laser device similar to that of the first embodiment, but further includes an excitation lamp. An excitation lamp 13 is added on the opposite side of 11, and the two excitation lamps 11.
A real laser rod 12 is excited from both openings. In this fifth embodiment, as in the first embodiment, the center of the partially cylindrical curved surface of the condenser 10 surrounding the excitation lamps 11 and 13, respectively! 121.23 are respectively excitation lamps 11
．． 13 axis 31.33 and laser rod 12 axis 32
The excitation lamps 11 and 13 are arranged so as to be on the plane connecting the axes 31 and 33 (that is, at a position shifted to (1) near the laser rod 12). 12 is arranged at the center position on the plane connecting the axes 31.33 of the two excitation lamps 11.13.In this embodiment, since the laser rod 12 is irradiated from both left and right sides, its cross section Furthermore, due to the arrangement according to the present invention, for the same reason as described in the first embodiment, the light intensity distribution is different from the height in the conventional example shown in FIG. The difference was about 65%, but the difference was 20%.
%, and the light energy = i is determined by aligning the axis 31.32 of the excitation lamp 11.13 with the center line 2 of the partially cylindrical curved surface.
1.23 Approximately 15% compared to the comparative example in Figure 8 placed above
It also rose. Further, this fifth embodiment is smaller in size by 2X (R2R1) than the comparative example shown in FIG. Note that in this embodiment, R+ = 1/2・R2, but similarly to the first embodiment, the present invention also provides R1=1/2・R2.
It is not limited to the point R2 or its vicinity. FIG. 9 is a sectional view showing the configuration of a sixth embodiment of the present invention. In this sixth embodiment, in the same laser device as the second embodiment, a laser rod 14 is further added on the opposite side of the laser rod 12, and one excitation lamp 11 is used to connect two laser rods 12. 14 is excited. In this sixth embodiment, the center line 22.24 of the partially cylindrical curved surface of the condenser 10 surrounding the laser rod 12.14 is
so as to be located on an extension of the plane connecting the axis 32.34 of the laser rod 12.14 and the axis 31 of the excitation lamp 11,
A laser rod 12.14 is arranged. Furthermore, the excitation lamp 11 is located at the axis 32 of the two laser rods 12 and 14.
．． It is arranged at the center position on the plane connecting 34. With this arrangement, the excitation light reflected by the mirror surface of the condenser 10 widely excites the surface of the laser rod 12.14, and the intensity distribution of the light emitted from the laser rod 12.14 is as follows: As shown in the characteristic curve F in the figure, the curve is gentle. That is, in FIG. 10, the characteristic IIA is related to the laser device disclosed in the prior art Japanese Patent Application Laid-open No. 50-85291 (see FIG. 23), in which the light intensity distribution has a height difference of about 65%. have. Further, the characteristic curve B is as shown in FIG.
The axis 32.34 of 4 is the center of the partial cylindrical curved surface: 422.
This is related to the comparative example arranged on No. 24, and the height difference in the light intensity distribution has been improved to about 20%. However, the total amount of optical energy of the laser beam emitted from the comparative example in FIG. 11 is the same as that of the conventional example (characteristic curve A) in FIG.
This is a decrease of about 40% compared to the previous year. In contrast, in the case of the sixth embodiment of the present invention, the light intensity distribution has only a height difference of about 20%, and the uniformity is greatly improved. Moreover, the total amount of optical energy of the laser beam emitted from the laser device of this example is increased by about 15% compared to the comparative example shown in FIG. In this way, in this embodiment, not only the distribution of light intensity is improved, but also the total amount of light energy is improved, resulting in high efficiency. Furthermore, as shown by the arrow in FIG. 10, the position where the light intensity distribution curve B) in the case of the comparative example in FIG. The light intensity distribution in one example (the position where the curved RF is maximum is close to the center of the laser medium). They considered the following: In the comparative example shown in FIG. 11, the laser rod 12.14 is strongly excited from the surface facing the excitation lamp 11. #lO circle frI
The light that hits the shaped part passes through the laser rod 14 without being irradiated with it, and does not contribute to excitation.On the other hand, in the sixth embodiment, similar light hits the laser rod 14 as shown in FIG. In addition, the laser rod 14 is irradiated with light, contributing to excitation. As a result, asymmetry is improved and higher efficiency is obtained than in the comparative example. Furthermore, in the sixth embodiment, by moving the center line 22.24 of the partially cylindrical curved surface of the condenser 1o inward from the axis 32.34 of the laser rod 12.14, , center line 2 of the partially cylindrical curved surface of the condenser lO
2.24 can be brought close to each other. Therefore, compared to the comparative example shown in FIG. 11, the size of the condenser lO5 and the t laser device can be reduced by 2x(R2-R+). Note that when the distance from the end of the condenser 10 to the axis 32.34 of the laser rod 12.14 is R1, and the radius of the condenser 10 is R2, as shown in FIG. 9, R1 is It has been confirmed that the most efficient and desirable state can be achieved by establishing the relationship R+ = 1/2・R2, but the present invention
It is not limited to the point 1/2·R2 or its vicinity. In this embodiment, the laser medium in a single laser device is operated as a laser oscillator and a laser amplifier, respectively.
This is suitable when it is desired to downsize the device. FIG. 12 is a sectional view showing the configuration of a seventh embodiment of the present invention. This seventh embodiment has a laser device similar to that of the sixth embodiment, but further includes an excitation lamp 15 on the right side of the laser rod 12.
, the laser rod 12 is connected to two excitation lamps 1
1.15 for excitation. The excitation lamp 15 has its axis 35 aligned with the center line 25 of the partially cylindrical curved surface surrounding the excitation lamp 15 and the laser rod 1.
It is arranged so as to be located on an extension of a plane connecting the two axes 32. In this embodiment, the laser rod 14 is used as an oscillator,
Laser rod 12 can be used as an amplifier. By changing the electrical input energy of the added excitation lamp 15, the amplification factor of the amplifier can be freely changed. The contents of the pond are the same as those in the sixth embodiment, so a description thereof will be omitted, but the light intensity distribution of both the laser rods 12 and 14 showed a gentle distribution almost similar to the curve F in FIG. 10. FIG. 13 is a sectional view showing the structure of an eighth embodiment of the present invention. This eighth embodiment uses a laser device similar to the sixth embodiment, with laser rods 6.17 above and below the excitation lamp 11.
12.14.1 Add each of the four laser rods.
6.17 are excited by one common excitation lamp 11. Said laser rod 16.17 also includes laser rod 12.1.
4, the axis 36.37 of the lathe rod 1
6. Centers of partial cylindrical surfaces surrounding each 17! 126.
27 and the axis 31 of the excitation lamp 11. The contents of the pond are the same as in the sixth embodiment, so the explanation will be omitted, but the light intensity distribution is the same as the laser rod 12.14.16.
．． Both No. 17 showed a gentle distribution almost similar to curve F in FIG. In this embodiment, one of the laser rods is used as an oscillator, and the remaining three
This is suitable when multi-stage amplification is desired by using one as an amplifier. FIG. 14 is a sectional view showing the structure of a ninth embodiment of the present invention. This ninth embodiment uses excitation rungs 18 and 19 above and below the laser rod 12 in a laser device similar to that of the fifth embodiment.
and four excitation lamps 11.13.18
．． 19 to excite one laser rod 12. Like the excitation lamp 11.13, the axis 38.39 of the excitation lamp 18.1 is aligned with the excitation lamp 18.19.
The laser rod 12 is disposed so as to be located on an extension of a plane connecting the center lines 28 and 29 of the partial cylindrical curved surfaces surrounding the laser rod 12 and the axis 32 of the laser rod 12. The other details are the same as those in the fifth embodiment, so the explanation will be omitted, but the light intensity distribution showed a gentle distribution almost similar to the curve F in FIG. 10. In addition, in each of the above embodiments, the excitation lamp 1
1.13.15.18.19 outer diameter is laser rod 1
It was said to be approximately the same outer diameter as 2.14.16.17, but
The relationship between the size of the excitation lamp and the size of the laser medium is not limited to this. In particular, when the outer diameter of the excitation lamp is small, it appears as a point light source, which improves the light condensing ability and improves the energy efficiency, although the energy distribution becomes a little non-uniform. Furthermore, it is possible to bring the reflective surface of the condenser 10 close to the diameter of the laser rod, which has the advantage of further downsizing. Hereinafter, embodiments of a laser device based on the above idea will be described in detail. FIG. 15 is a sectional view showing the structure of a tenth embodiment of the present invention. In the tenth embodiment, an excitation lamp 11 having a lamp outer diameter smaller than the diameter of the laser rod 12 is used in the same laser device as the first embodiment. Other points are the same as those in the first embodiment, so explanations will be omitted. In this example, the energy distribution showed a gentle curve almost similar to curve C in FIG. 2, and the height difference was about 22%, so the deterioration of the energy distribution was not large. The energy efficiency was better than the first example and 20% higher than the comparative example shown in FIG. Further, in this embodiment, the reflecting surface can be made small to be close to the outer diameter of the laser rod 12, as in the modification shown in FIG. Therefore, it is possible to downsize the device without changing the energy efficiency or the height difference of the energy distribution. FIG. 17 is a sectional view showing the structure of an eleventh embodiment of the present invention. In this eleventh embodiment, an excitation lamp 11 having a lamp outer diameter smaller than the diameter of the laser rod 12 is used in a laser device similar to the third embodiment. Other points are the same as those in the third embodiment, so explanations will be omitted. In this 11th embodiment, as in the 3rd embodiment, the energy distribution shows a gentle curve almost similar to the curve in FIG. 2, the difference in height is about 27%, and the energy efficiency is compared with that in FIG. It was 28% higher than the previous example. FIG. 18 is a sectional view showing the structure of a twelfth embodiment of the present invention. In this twelfth embodiment, two excitation lamps 11 and 13 whose outside diameters are smaller than the diameter of the laser rod 12 are used in a laser device similar to that of the fifth embodiment. Other points are the same as those in the fifth embodiment, so explanations will be omitted. The height difference of the energy distribution in this twelfth embodiment is 22
%, and the energy efficiency is 20% compared to the comparative example in Figure 8.
It was rising. FIG. 19 is a sectional view showing the structure of a thirteenth embodiment of the present invention. In this thirteenth embodiment, in a laser device similar to the seventh embodiment, the outer diameter of the excitation lamp 11 is the same as that of the laser rod 12.
The outer diameter of the excitation lamp 15 is smaller than the outer diameter of the excitation lamp 11. Further, the axis 34 of the laser rod 14 is aligned with the center line 24 of the curved surface of the partial barrel. Other points are the same as those in the seventh embodiment, so explanations will be omitted. In this thirteenth example, the energy distribution of the laser rod 14 showed a gentle distribution approximately between curves B and F in FIG. 10, and the energy efficiency was increased by 5% compared to the comparative example in FIG. 11. On the other hand, although the height difference in the energy distribution of the laser rod 12 was 22%, the energy efficiency was 20% higher than the comparative example shown in FIG. In this embodiment, the outer diameter of the excitation lamp 15 is made smaller than the outer diameter of the excitation rung 11 because the excitation lamp 11 excites two laser rods 12.14, whereas the excitation lamp 15 excites only one laser rod. This is because only the main laser rod 12 is excited. In particular, when the laser rod 12 is used as an amplifier and the excitation lamp 15 is used for gain control thereof, the outer diameter of the excitation lamp 15 may be small. FIG. 20 is a sectional view showing the configuration of a fourteenth embodiment of the present invention. In this 14th embodiment, a laser device similar to that of the 9th embodiment uses excitation lamps 11, 13, 18, and 19 whose outer diameters are smaller than the diameter of the laser rod 12. Other points are the same as those in the ninth embodiment, so explanations will be omitted. The light intensity distribution in this 14th example showed a gentle distribution similar to curve F in FIG. 10, almost the same as in the 9th example. In addition, the energy efficiency is further increased by 5% compared to the ninth embodiment.
It was quite high. In the above embodiment, the excitation lamps 11, 13.
A cylindrical one is used as 15.18.19, and a solid columnar laser rod 12.14.16 is used as the laser medium.
．． 17 was used, but the shape of the excitation lamp and laser medium is not limited to this. For example, a columnar excitation lamp may be used, and as the laser medium, for example, the shape is disclosed in JP-A No. 62-262480. It is also possible to use a hollow columnar type.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the configuration of a first embodiment of a laser device according to the present invention, FIG. 2 is a characteristic curve diagram showing an example of the intensity distribution of light emitted from a laser medium, and FIG. , FIG. 4 is a sectional view showing the configuration of a comparative example of the first embodiment, FIG. 4 is a sectional view showing the configuration of the second embodiment of the present invention, and FIG. 5 is a cross-sectional view showing the configuration of the third embodiment of the present invention. 6 is a sectional view showing the configuration of a fourth embodiment of the present invention, FIG. 7 is a sectional view showing the configuration of a fifth embodiment of the present invention, and FIG. 8 is a sectional view showing the configuration of a fifth embodiment of the present invention. FIG. 9 is a cross-sectional view showing the structure of a sixth embodiment of the present invention; FIG. 10 is a characteristic curve showing an example of the intensity distribution of light emitted from the laser medium. Figure 11 is a cross-sectional view showing the configuration of a comparative example of the sixth example, Figure 12 is a cross-sectional view showing the configuration of the seventh example of the present invention, and Figure 13 is a cross-sectional view showing the configuration of the seventh example of the present invention. 14 is a sectional view showing the structure of a ninth embodiment of the present invention; FIG. 15 is a sectional view showing the structure of a tenth embodiment of the present invention; FIG. 16 is a sectional view showing the structure of a tenth embodiment of the present invention. 17 is a cross-sectional view showing the structure of the eleventh embodiment of the present invention. FIG. 18 is a cross-sectional view showing the structure of the twelfth embodiment of the present invention. 19 is a sectional view showing the structure of the thirteenth embodiment of the present invention. FIG. 20 is a cross-sectional view showing the structure of the fourteenth embodiment of the present invention. 51-40894, FIG. 22 and FIG. 23 are cross-sectional views showing the structure of a conventional example disclosed in JP-A-50-85291, and FIG. It is a sectional view showing the structure of a conventional example disclosed in 183193/1983. 10... Light collector, 11.13.15.18.19... Excitation lamp, 12
．． 14.16.17... Laser rod, 21.22.
23.24.2, 26.27.28.29... Center line of partially cylindrical curved surface, 31.33.35.38.39... Axis center of excitation lamp, 32.34.36.37. ...The axis of the laser rod.

Claims (3)

[Claims] (1) One or more axially symmetrical columnar laser media;
Formed by two or more columnar excitation light sources, two partial cylindrical curved surfaces and two or more partial planes that substantially uniformly surround the laser medium and the excitation light source in translational symmetry in their axial directions. a condenser having a reflecting surface that is shaped like a cylinder, and a center line of the partially cylindrical curved surface, an axis of the laser medium, and an axis of the excitation light source are in the same plane, and the partially cylindrical surface of the reflecting surface is Two laser media facing the curved surface, 1
one laser medium and one excitation light source, or a laser characterized in that the axis of at least one of the two excitation light sources is shifted to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. Device. (2) one columnar excitation light source; four columnar laser media surrounding the excitation light source and arranged parallel to each other; and the laser medium and the excitation light source being translationally symmetrical in their axial directions. and a condenser having a reflecting surface formed by four partial cylindrical curved surfaces or four partial cylindrical curved surfaces and four or more partial planes substantially uniformly surrounding the excitation light source, and the axes of the excitation light sources are perpendicular to each other. The center lines of the two partial cylindrical curved surfaces and the axes of the two laser media that are opposite to the partial cylindrical curved surfaces coincide with the intersection line of the two planes, and are within one plane forming the two perpendicular planes. and the center lines of the other two partial cylindrical curved surfaces and the axes of the other two laser media facing those partial cylindrical curved surfaces are within another plane forming the two orthogonal planes, The axial center of at least one of the four laser media facing the partial cylindrical curved surface of the reflective surface is shifted to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. Laser equipment for (3) one columnar laser medium, four columnar excitation light sources surrounding the laser medium and arranged parallel to each other, and the laser medium and the excitation light source being translationally symmetrical in their axial directions; and a condenser having a reflective surface formed by four partial cylindrical curved surfaces or four partial cylindrical curved surfaces and four or more partial planes, which are substantially uniformly surrounded, and the axes of the laser medium are perpendicular to each other. The center lines of the two partial cylindrical curved surfaces and the axes of the two excitation light sources, which coincide with the intersection line of the two planes and are opposed to the partial cylindrical curved surfaces, are within one plane forming the two orthogonal planes. and the center lines of the other two partial cylindrical curved surfaces and the axes of the other two excitation light sources facing those partial cylindrical curved surfaces are within another plane forming the two orthogonal planes, The axial center of at least one of the four excitation light sources facing the partial cylindrical curved surface of the reflective surface is shifted to a position closer to the partial cylindrical curved surface than the center line of the partial cylindrical curved surface. Laser equipment for