JPH0637406A - Metal vapor laser device - Google Patents

Abstract

PURPOSE:To provide a metal vapor laser device, in which the consumption of metallic vapor is reduced largely and not only operation for a prolonged term is enabled but also laser transmission having a high output and high efficiency is enabled. CONSTITUTION:The thickness of a heat-resistant heat-insulating member 2 positioned at the central section in the axial direction of a discharge tube 1 is made thinner than that of the end section of the member 2 so that a heat- insulating member 2 mounted in a coaxial manner on the outer circumference of the discharge tube 1, in which metallic sources 9 are heated and vaporized by discharge energy in a gas and metallic vapor is generated and a laser medium composed of the metallic vapor is formed, has heat-insulating characteristics shaping tube-wall temperature distribution in the discharge tube having bimodal characteristics, in which a tube-wall temperature at a central section in the discharge tube 1 is minimized and a tube-wall temperature between the central section of the discharge tube and the end section of the discharge tube is maximized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal vapor laser device, and more particularly to a metal vapor laser device which heats a metal contained in a discharge tube in advance by gas discharge to vaporize and excite it to obtain a laser output. .

[0002]

2. Description of the Related Art A conventional metal vapor laser device is, for example,
As disclosed in Japanese Unexamined Patent Publication No. 281773/1990, since the temperature of the wall in the discharge tube is raised to a predetermined temperature (for example, about 1,500 ° C in a copper vapor laser) by the discharge energy in the gas, a ceramic discharge is generated. A composite structure in which an electrically insulating cylindrical heat insulating member having a uniform thickness along the discharge tube axial direction and having uniform heat insulating properties is provided on the outer circumference of the tube, and a vacuum heat insulating layer is further provided on the outer circumference thereof. A heat insulation structure is adopted to strengthen the heat insulation in the radial direction of the discharge tube.

Further, in Japanese Patent Application Laid-Open No. 63-229782, there is provided a second electrically insulating material having a uniform thickness along the discharge tube axis direction inside the vacuum heat insulating layer and having uniform heat insulating characteristics. By disposing a cylindrical heat insulating member, the heat insulating performance in the radial direction of the discharge tube is further improved.

[0004]

According to the above-mentioned conventional metal vapor laser device, the thickness of the cylindrical heat insulating member disposed on the outer periphery of the discharge tube is uniform along the axial direction of the discharge tube, and Since it had uniform heat insulation performance, the temperature of the wall inside the discharge tube was maximum at the central part in the axial direction of the discharge tube and formed a monomodal wall temperature distribution that monotonically decreased toward the end. .

As a result, the metal vapor density is uniquely determined by the tube wall temperature in the discharge tube, and the laser output and the oscillation efficiency are optimized by the appropriate tube wall temperature, that is, the appropriate metal vapor density in the discharge tube. According to the above fact, in the above-mentioned monomodal tube wall temperature distribution, the metal vapor density also reaches its maximum in the central part of the discharge tube and monotonically decreases from the central part toward the end, so that the effective area that can contribute to laser oscillation is However, it is limited to the high temperature region in the central portion of the discharge tube where the metal vapor density is high, and the conventional device has not been able to efficiently form the laser medium in the discharge tube.

Therefore, the ratio of the laser medium length to the discharge length is small. Therefore, in order to increase the output of the laser device, the discharge volume must be increased, and the length of the discharge tube must be increased. Due to the increase in the discharge resistance and the self-inductance of the discharge tube, it is necessary to increase the voltage of the power supply.For the larger diameter of the discharge tube, the skin effect of the discharge current causes
There is a problem that the laser beam becomes a ring mode due to the decrease in the gain in the central portion in the radial direction of the discharge tube, and the oscillation efficiency is decreased.

Further, since the density of the metal vapor serving as the laser medium monotonically decreases toward the end of the discharge tube, a large density gradient is generated between the central portion and the end of the discharge tube, and as a result, the metal vapor flows toward the end of the discharge tube. Since it diffuses and agglomerates and solidifies in the low temperature region of the edge, the metal vapor is consumed so much that it is difficult to operate the laser device for a long time.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a metal vapor laser device capable of performing highly efficient laser emission with a high output, as well as being able to drastically reduce the consumption of metal vapor and operating for a long time.

[0009]

DISCLOSURE OF THE INVENTION According to the present invention, a metal source is heated and evaporated by discharge energy in a gas to generate a metal vapor, and a laser medium made of the metal vapor is coaxially formed on the outer circumference of the discharge tube. The heat insulating member provided has a twin-peaked discharge tube inner wall temperature in which the temperature of the inner wall of the discharge tube is minimized and the temperature of the wall between the center of the discharge tube and the end of the discharge tube is maximized. It is characterized by having adiabatic properties that form a distribution.

[0010]

According to the metal vapor laser device having the above-described structure of the present invention, the metal vapor generated by heating and evaporating the metal lump previously arranged in the discharge tube by the discharge energy in the gas is the bimodal one. Due to the density gradient caused by the temperature distribution of the heat-generating tube wall, it diffuses simultaneously in both the central part and the end part of the discharge tube.

For this reason, in a steady state where the density gradient of the metal vapor is zero except for the end of the discharge tube, the region where the metal vapor is uniformly distributed expands along the axial direction of the discharge tube and becomes long.
In addition, since the flat metal vapor density distribution is formed, the above object is achieved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The metal vapor laser device of the present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of the metal vapor laser device of the present invention.

As shown in the figure, a plurality of metal ingots 9 are previously formed.
A cylindrical discharge tube 1 made of a heat-resistant ceramic that accommodates is coaxially surrounded by a cylindrical heat-insulating layer 2 made of a heat-resistant ceramic fiber.
Further, a cylindrical heat-resistant glass tube 3 is coaxially arranged.

The cylindrical heat-resistant glass tube 3 accommodating the discharge tube 1 and the heat insulating layer 2 has O-rings or the like on the metal flanges 8a to 8c provided on the laser tube body 5 made of metal at both ends (see FIG. It is supported via an elastic member (not shown), which absorbs the expansion of the discharge tube 1 and the heat-resistant glass tube 3 in the axial direction of the discharge tube at high temperature and prevents thermal stress cracking.

Further, the space surrounded by the heat-resistant glass tube 3 and the laser tube body 5 is sealed with the O-ring or the like, and the vacuum heat insulating layer 4 is formed by vacuuming, so that the heat insulation is further enhanced. I am trying.

A cylindrical sleeve 7 for electrical insulation is provided between the metal flanges 8a and 8b, and cylindrical electrodes 6a and 6b are mechanically fixed to the metal flanges 8a and 8c, respectively. It is connected.

When a high voltage pulse is applied from an external electric circuit (not shown) between the cylindrical electrodes 6a and 6b,
Plasma is generated and propagates in the discharge space 10 sandwiched between the electrodes 6a and 6b in the buffer gas previously sealed inside the discharge tube 1, and the pulse discharge current flows between the electrodes 6a and 6b via this plasma. And further flows through the metal laser tube body 5 via the electrodes. At this time, the discharge space 10 and the laser tube main body 5 form a coaxial structure, and the direction 11a of the discharge current flowing through the discharge space 10 is opposite to the direction 11b flowing through the laser tube main body 5. Has a reduced self-inductance, and has a structure capable of obtaining a fast rising discharge current suitable for a metal vapor laser device utilizing a self-terminating transition between upper and lower laser levels.

As a result, a part of the pulse discharge energy is transferred to the metal vapor, and a population inversion state is formed in a part of the metal vapor atoms, so that an optical resonator (not shown) for stimulated emission light. Laser oscillation is achieved by the amplifying action by.

In the conventional laser device, as described above, the outer circumference of the discharge tube 1 is coaxially arranged with the heat insulating layer 2 having a uniform thickness and uniform heat insulating property, and therefore, the tube wall. Since the temperature was maximum in the central part in the axial direction of the discharge tube and formed a monomodal distribution that monotonically decreased toward the end, the metal vapor density of the laser medium, like the tube wall temperature, was also monomodal. It will have a distribution.

For this reason, the effective region in the discharge tube 1 which can contribute to laser oscillation is limited to the high temperature region of the central portion, so that the laser output and the oscillation efficiency can be improved without increasing the discharge volume. Was difficult.

Therefore, in this embodiment, as shown in detail in FIG. 2, the thickness of the heat insulating layer 2 at the central portion in the axial direction is reduced, and the heat radiation in the radial direction at the central portion is discharged. It becomes more noticeable than the heat radiation in the thick heat insulating region sandwiched between the central portion and the end portion of the tube 1.

Therefore, as shown in FIG. 3 which shows the characteristics of the tube wall temperature 12 and the copper vapor density distributions 13a and 13b with respect to the axial length of the discharge tube, the tube wall temperature 12 at the central portion of the discharge tube becomes minimum, while the discharge The tube wall temperature 12 in the region sandwiched between the central part and the end part of the tube can form a maximally bimodal tube wall temperature distribution.

As a result, as shown in FIG. 3, the metal vapor that has reached the saturated vapor pressure peculiar to the metal, which is determined by the tube wall temperature, transiently has the tube wall temperature 12 at the minimum center in the axial direction of the discharge tube. Density distribution where the copper vapor density is minimal in the area, and is maximal in the area sandwiched between the center and the end in the axial direction of the discharge tube.
will exhibit a.

However, similarly, since the density gradient of the metal vapor is generated in the discharge tube 1 due to the bimodal density distribution 13a of the metal vapor shown in FIG. 3, the density gradient of the metal vapor is directed toward the central portion and the end portion in the axial direction of the discharge tube. At the same time diffusion of metal vapors 14a, 14b, 1
4c and 14d occur, and the equilibrium state 13b having a uniform metal vapor density distribution can be constantly formed in the discharge tube 1 except at least the outermost end in the axial direction of the discharge tube.

As a result, the ratio of the laser medium length to the discharge length increases, and the diffusion region is limited to the outermost end of the discharge tube 1, so that the high output and high oscillation can be achieved without increasing the discharge volume. It is possible to provide a metal vapor laser device that is efficient and can be operated for a long time.

Although the heat insulating member 2 shown in FIG. 2 has an integrated structure having uniform heat insulating characteristics, a plurality of heat insulating members 2 having the same heat insulating performance as in the other embodiments shown in FIGS. The above bimodal tube wall temperature distribution can also be achieved by combining the above heat insulating members.

That is, in the embodiment shown in FIG. 4, the heat insulating layer 2 is divided into three parts in the axial direction, and a heat insulating layer having a thin central portion and thick heat insulating layers at both ends thereof are butted against each other. Is configured.

In the embodiment shown in FIG. 5, the heat insulating member has a structure in which a thin heat insulating layer at the central portion and thick heat insulating layers at both ends thereof are fitted to each other.

In the embodiment shown in FIG. 6, the heat insulating member is constructed by abutting structure of heat insulating layers divided into two in the axial direction at a thin portion of the central portion.

In the embodiment shown in FIG. 7, the heat insulating member having a structure in which the heat insulating layer having a small thickness at the central portion and the heat insulating layer having a large thickness on one side are integrated, and the remaining heat insulating layer having a large thickness is abutted against each other. It was done.

In the embodiment shown in FIG. 8, a heat insulating member is constructed by modifying the butt structure shown in FIG. 7 into a mating structure.

In the embodiment shown in FIG. 9, the abutting structure shown in FIG. 6 is transformed into a mating structure in the thin central portion to form a heat insulating member.

In the embodiment shown in FIG. 10, a further heat insulating layer is coaxially arranged on the outer periphery of the end portion of an integrated heat insulating layer having a uniform thickness to form a heat insulating member.

In the embodiment shown in FIG. 11, the outer periphery of one end of the thick heat insulating layer is tapered, and the heat insulating member is formed by abutting the tapered heat insulating layer and the thin heat insulating layer. .

In the embodiment shown in FIG. 12, a heat insulating member is constructed by the abutting structure of the above-mentioned tapered heat insulating layers.

In the above heat insulating structure, the thickness of the heat insulating layer 2 at the central portion in the axial direction is made thin, so that the outer peripheral length of the heat insulating layer located at the central portion in the axial direction of the discharge tube 1 is made shorter than the end portion thereof. However, in the embodiment shown in FIG. 13, conversely, in the three-divided heat insulating member, the inner peripheral length of the central portion of the heat insulating layer 2 is made longer than the inner peripheral length of the end portion, and the abutting is performed. It is characterized by having a structure. The other structure is similar to that shown in FIG.

The embodiment shown in FIG. 14 has a structure in which a heat insulating layer having a short inner circumference and a heat insulating layer having a long outer circumference are integrated with each other, and the heat insulating layer and the remaining heat insulating layer having a short inner circumference are butted against each other. This is a heat insulating member.

The embodiment shown in FIG. 15 is a modification of the fitting structure of the butt structure of FIG.

The embodiment shown in FIG. 16 is an example in which FIG. 13 is modified into a fitting structure.

The embodiment shown in FIG. 17 has a structure in which a heat insulating layer is coaxially arranged on the inner surface of an end of an integral heat insulating layer having uniform heat insulating properties.

The embodiment shown in FIG. 18 has a butt structure of heat insulating layers in which the inner surface of the end is tapered.

The embodiment shown in FIG. 19 is similar to that of FIG.
This is an example in which a uniform heat insulating layer member having a long inner peripheral length is inserted in the central portion in the axial direction to form a butt structure.

In the embodiment shown in FIG. 20, another heat insulating layer 15 is coaxially provided on the outer periphery of the heat-resistant glass tube 3 accommodating the discharge tube 1 and the heat insulating layer 2 and at a portion other than the central portion of the discharge tube 1. It is characterized in that it is arranged in a shape.

The embodiment shown in FIG. 21 is the heat insulating layer 1 of FIG.
It is characterized in that at least one or more metal heat radiation plates 16 are provided in the same portion as in FIG.

In the embodiment shown in FIG. 22, the heat absorber 17 is provided on the inner surface of the metallic laser tube body 5 located in the central portion of the discharge tube 1 in the vacuum heat insulating layer 4, and the radial direction of the central portion of the discharge tube 1 is set. Radiant heat from the heat absorbing body 17 is absorbed by the heat absorbing body 17, and the absorbed heat is removed by a cooling layer 19 such as water or oil provided on the outer circumference of the vacuum heat insulating layer 4, and the tube at the central portion in the axial direction of the discharge tube 1 is removed. It is characterized in that the wall temperature is lowered from the end.

In the embodiment shown in FIG. 23, at least one portion is provided in the vacuum heat insulating layer 4 at a portion located at the central portion in the axial direction of the discharge tube 1.
One or more metal heat radiation plates 16 are provided.
By providing a plurality of openings 18 in the discharge tube 1, heat dissipation from the axial center radial direction of the discharge tube 1 is promoted through the openings 18.

In the embodiment shown in FIG. 25, the cooling layer 20 is coaxially arranged on the outer periphery of the vacuum heat insulating layer 4, and the cooling layer 20 is located at the central portion of the discharge tube 1 in the axial direction. 5
By forming the compartment 20 by the metal flanges 8d and 8e provided in the compartment, the temperature of the cooling medium in the compartment 20 is
It is characterized in that the temperature of the cooling refrigerant flowing in the cooling layers 19 on both sides thereof is made lower than that of the cooling tube 19 so that a large amount of heat from the central portion of the discharge tube 1 is absorbed and removed from the axial end portion.

The embodiment shown in FIG. 26 has a metal flange 8d.
And 8e provide a compartment 20 in a region surrounded by the heat-resistant glass tube 3 and the metal laser tube body 5 located in the axial center of the discharge tube 1 via an elastic member such as an O-ring. Two
As in the fifth embodiment, a coolant having a temperature lower than that of the cooling layers 19 on both sides is made to flow in the compartment 20 to absorb and remove a large amount of heat from the axial central portion of the discharge tube 1 compared to the end portion. I am trying.

In the embodiment shown in FIG. 27, in the vacuum heat insulating layer 4, a spring-shaped plate 21 made of, for example, a good heat conductor such as metal is attached to a portion of the vacuum heat insulating layer 4 located at the central portion in the axial direction of the discharge tube 1. By disposing in contact with the outer peripheral surface of the metal laser tube main body 5 and the inner peripheral surface of the metal laser tube main body 5, the heat transferred in the radial direction from the central portion in the axial direction of the discharge tube 1 is transferred to the heat conduction of the spring-shaped plate 21. It is characterized in that heat is radiated to the metal laser tube body 5 via the.

The embodiment shown in FIG. 28 is similar to that of FIG.
As shown in FIG. 29, for example, a ring-shaped spring plate member 21 made of a metal good heat conductor is provided on the outer peripheral surface of the heat-resistant glass tube 3 in a portion of the vacuum heat insulating layer 4 located at the central portion in the axial direction of the discharge tube 1. By arranging in contact with the surface and the inner peripheral surface of the laser tube main body 5, the heat conduction of the metal spring-shaped plate member 21
It is characterized in that heat is radiated to the metal laser tube body 5.

Further, as shown in FIG. 30, for example, a ring-shaped spring-like plate member 21 made of a metal good conductor is provided in the vacuum heat insulating layer 4 located at the central portion in the axial direction of the discharge tube 1. Good.

In the embodiment shown in FIG. 31, in the heat insulating member 2 that surrounds the outer circumference of the discharge tube 1 coaxially, as shown in FIG. 32, the bulk density of the heat insulating member located at the axial center of the discharge tube 1 is It is characterized in that it is made smaller than the bulk density of the heat insulating member at the end to promote heat dissipation from the axial center of the discharge tube 1 from the end.

The structure of the heat insulating member shown in FIG. 33 is a cylindrical structure having uniform heat insulating properties, and a plurality of heat insulating members each having a higher thermal conductivity than the heat insulating member forming the heat insulating layer 2 are provided in the axial central portion of the heat insulating layer 2. The heat insulating members 23a, 23b, and 23c are alternately arranged with the heat insulating layer 2. Thereby, as is clear from the heat conduction state diagram shown in FIG. 34, the heat flux transferred through the tube wall in the radial direction of the discharge tube 1 directly passes through the heat insulating layer 2 and the heat insulating members 23a, 23b, 23c, respectively. Since the heat insulating layer 2 having low thermal conductivity is adjacent to the heat insulating members 23a, 23b, and 23c having high heat conductivity alternately, the heat insulating layer 2 to the heat insulating member 23a,
Heat flux 24 is generated by heat conduction to 23b and 23c.

As a result, the heat radiation from the central portion of the discharge tube 1 is promoted through the heat insulating members 23a, 23b and 23c having high thermal conductivity, and the heat radiation from the area sandwiched between the central portion and the end portion of the discharge tube 1 is performed. Since it is remarkable in comparison, a steady uniform metal vapor density distribution 13b similar to that shown in FIG. 3 can be formed in the discharge tube 1.

In the embodiment shown in FIG. 35, the outer peripheral surface of the heat-resistant glass tube 3 accommodating the discharge tube 1 and the heat insulating member 2 in the vacuum heat insulating layer 4 is a portion excluding at least the central portion in the axial direction of the discharge tube 1. In addition, for example, by disposing a heat-generating body 25 which is covered with electric insulation and heating the heat-resistant glass tube 3 by the heat-generating body 25, it is possible to form a bimodal tube wall temperature distribution in the discharge tube 1. Characterize.

The embodiment shown in FIG. 36 is characterized in that the heating element 25 is arranged on the outer peripheral surface of the laser tube main body 5 at least at a portion except the central portion in the axial direction of the discharge tube 1.

[0058]

According to the metal vapor laser device of the present invention described above, a discharge for heating and evaporating a metal source by the discharge energy in gas to generate metal vapor and forming a laser medium made of the metal vapor. The heat insulating member coaxially provided on the outer periphery of the tube has a twin-peak structure in which the tube wall temperature in the central portion of the discharge tube is minimized and the tube wall temperature between the discharge tube central portion and the discharge tube end is maximized. Since it has adiabatic characteristics that form the temperature distribution inside the discharge tube, the metal generated in advance by heating and evaporating the metal mass that was previously placed in the discharge tube due to the discharge energy in the gas. Since the vapor is simultaneously diffused in both directions of the central portion and the end portion of the discharge tube due to the density gradient caused by the bimodal tube wall temperature distribution, the density gradient of the metal vapor is different except for the outermost end portion of the discharge tube. In a steady state of zero, metal vaporization The area in which the gas is evenly distributed expands along the axial direction of the discharge tube, and a long and flat metal vapor density distribution is formed.Therefore, the temperature of the wall inside the discharge tube is doubled along the axial direction of the discharge tube. It has a ridged distribution, and a long and flat metal vapor density distribution is obtained in the axial direction of the discharge tube. Therefore,
The ratio of the laser medium length in the axial direction of the discharge tube to the discharge length is increased, and high output and highly efficient laser oscillation can be obtained.

Further, due to the expansion of the flat metal vapor density distribution in the axial direction of the discharge tube, the region in which the metal vapor is diffused in the discharge tube is limited to at least only the end portion of the discharge tube. Since the consumption is greatly reduced, it is possible to provide a metal vapor laser device that can be operated for a long time.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of a metal vapor laser device of the present invention.

FIG. 2 is a cross-sectional perspective view of a heat insulating member used in an embodiment of the metal vapor laser device of the present invention.

FIG. 3 is an axial distribution characteristic diagram of a tube wall temperature and a metal vapor density in a discharge tube in an embodiment of the metal vapor laser device of the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 5 is a sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 7 is a cross-sectional view showing another embodiment of a heat insulating member used in the present invention.

FIG. 8 is a sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 9 is a cross-sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 10 is a sectional view showing another embodiment of a heat insulating member adopted in the present invention.

FIG. 11 is a sectional view showing another embodiment of the heat insulating member adopted in the present invention.

FIG. 12 is a sectional view showing another embodiment of a heat insulating member used in the present invention.

FIG. 13 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

14 is a cross-sectional view showing another embodiment of the heat insulating member used in the embodiment shown in FIG.

15 is a cross-sectional view showing another embodiment of the heat insulating member used in the embodiment shown in FIG.

16 is a cross-sectional view showing another embodiment of the heat insulating member adopted in the embodiment shown in FIG.

17 is a cross-sectional view showing another embodiment of the heat insulating member used in the embodiment shown in FIG.

FIG. 18 is a cross-sectional view showing another embodiment of the heat insulating member adopted in the embodiment shown in FIG.

FIG. 19 is a cross-sectional view showing another embodiment of the heat insulating member adopted in the embodiment shown in FIG.

FIG. 20 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 21 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 22 is a half sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 23 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 24 is a perspective view showing details of a heat radiation plate adopted in the embodiment shown in FIG. 23.

FIG. 25 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 26 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 27 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 28 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

29 is a cross-sectional view taken along line I-II of FIG. 28.

FIG. 30 is a partial cross-sectional view showing another embodiment of the spring plate member adopted in FIG. 28.

FIG. 31 is a half cross-sectional view showing another embodiment of the metal vapor laser device of the present invention.

32 is a sectional perspective view showing another embodiment of the heat insulating member adopted in FIG. 31. FIG.

33 is a sectional perspective view showing another embodiment of the heat insulating member adopted in FIG. 31. FIG.

34 is a diagram showing a heat conduction state of the heat insulating member shown in FIG. 33.

FIG. 35 is a sectional perspective view showing another embodiment of the metal vapor laser device of the present invention.

FIG. 36 is a sectional perspective view showing another embodiment of the metal vapor laser device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylindrical discharge tube, 2 ... Cylindrical heat insulation layer, 3 ... Heat-resistant glass tube, 4 ... Vacuum heat insulation layer, 5 ... Laser tube main body, 6a, 6b ...
Cylindrical electrode, 7 ... Electrically insulating sleeve, 8a, 8b, 8
c, 8d, 8e ... Metal flange, 9 ... Metal ingot, 10 ... Discharge space, 11a, 11b ... Direction of discharge current, 12 ... Tube wall temperature, 13a ... Transient distribution of metal vapor density, 13b ... Steady state of metal vapor density Distribution, 14a, 14b, 14c, 14d
... direction of diffusion of metal vapor, 15 ... heat insulating member, 16 ... heat radiating plate, 17 ... heat absorber, 18 ... aperture, 19 ... cooling layer, 2
0 ... compartment, 21 ... spring-like plate material, 23a, 23b, 23c
... A heat insulating member having a high thermal conductivity, 25 ... A heating element.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Wada Akira Wada 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitate Manufacturing Co., Ltd.Hitachi Laboratory Ltd. Hitachi Research Laboratory

Claims (34)

[Claims] 1. A discharge tube for heating and evaporating a metal source by discharge energy in a gas to generate a metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer circumference of the discharge tube. In a metal vapor laser device comprising a heat insulating member and a metal laser tube coaxially provided on the outer periphery of the heat insulating member and forming a vacuum heat insulating layer, the heat insulating member is a tube wall in a central portion of the discharge tube. It is characterized by having adiabatic characteristics that form a twin-peaked inner wall temperature distribution of the discharge tube that minimizes the temperature and maximizes the tube wall temperature between the discharge tube center and the discharge tube end. Metal vapor laser equipment. 2. A discharge tube for heating and evaporating a metal source by discharge energy in a gas to generate a metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. In a metal vapor laser device provided with a heat insulating member and a metal laser tube coaxially provided on the outer periphery of the heat insulating member and forming a vacuum heat insulating layer, the tube wall temperature at the central portion in the discharge tube becomes minimum, Further, the thickness of the axial center portion of the heat insulating member is adjusted so as to form a bimodal inner wall temperature distribution of the discharge tube that maximizes the tube wall temperature between the discharge tube central portion and the discharge tube end portion. A metal vapor laser device characterized by being made thinner than the thickness of the portion. 3. A discharge tube for heating and evaporating a metal source by discharge energy in a gas to generate a metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. In a metal vapor laser device provided with a heat insulating member and a metal laser tube coaxially provided on the outer periphery of the heat insulating member and forming a vacuum heat insulating layer, the tube wall temperature at the central portion in the discharge tube becomes minimum, And, in order to form a temperature distribution of the inner wall of the discharge tube having a bimodal characteristic in which the temperature of the wall between the center of the discharge tube and the end of the discharge tube becomes maximum, the heat insulating member located in the center of the discharge tube in the axial direction is formed. A metal vapor laser device characterized in that the outer peripheral length is shorter than the end portion. 4. A discharge tube for heating and evaporating a metal source by discharge energy in gas to generate metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer circumference of the discharge tube. In a metal vapor laser device provided with a heat insulating member and a metal laser tube coaxially provided on the outer periphery of the heat insulating member and forming a vacuum heat insulating layer, the tube wall temperature at the central portion in the discharge tube becomes minimum, And, in order to form a temperature distribution of the inner wall of the discharge tube having a bimodal characteristic in which the temperature of the wall between the center of the discharge tube and the end of the discharge tube becomes maximum, the heat insulating member located in the center of the discharge tube in the axial direction is formed. A metal vapor laser device characterized in that the inner peripheral length is made longer than the inner peripheral length of the end portion. 5. A discharge tube for heating and evaporating a metal source by gas discharge energy to generate a metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer circumference of the discharge tube. In a metal vapor laser device provided with a heat insulating member and a metal laser tube coaxially provided on the outer periphery of the heat insulating member and forming a vacuum heat insulating layer, the tube wall temperature in the central portion of the discharge tube becomes minimum, In addition, the heat insulation performance of the axial center portion of the heat insulating member is adjusted so that a tube wall temperature distribution between the discharge tube central portion and the discharge tube end portion has a maximum bimodal characteristic. A metal vapor laser device characterized in that the heat insulation performance of the end portion is lowered. 6. The metal vapor laser device according to claim 2, wherein the heat insulating member having a thickness at a central portion in the axial direction smaller than a thickness at an end portion thereof is integrally formed. . 7. The heat insulating member in which the thickness of the central portion in the axial direction is thinner than the thickness of the end portion thereof is divided into three in the axial direction, and the heat insulating member having the thin central portion and the thick thermal insulating members at both ends thereof. 4. The metal vapor laser device according to claim 2, wherein and are formed in a butted structure. 8. The heat insulating member having an axially central portion thinner than the end portions thereof is divided into three parts in the axial direction, and the central portion has a thin thermal insulating member and both ends thereof have a thick thermal insulating member. The metal vapor laser device according to claim 2 or 3, characterized in that the mating structure is formed. 9. The heat insulating member, wherein the thickness of the central portion in the axial direction is thinner than the thickness of the end portion thereof, is divided into two in the axial direction at the thin portion of the central portion, and the portion is formed in a butt structure. The metal vapor laser device according to claim 2 or 3, characterized in that: 10. The heat insulating member, wherein the thickness of the central portion in the axial direction is smaller than the thickness of its end portion, has a structure in which the thin thermal insulating member of the central portion and one thick thermal insulating member are integrally formed, and remain. The metal vapor laser device according to claim 2 or 3, wherein the thick heat insulating member is formed in a butt structure. 11. The heat insulating member, wherein the thickness of the central portion in the axial direction is made smaller than the thickness of the end portion thereof, has a structure in which a heat insulating member having a small thickness at the central portion and one heat insulating member having a large thickness are integrally formed, and this remains. The metal vapor laser device according to claim 2, wherein the heat insulating member having a large thickness is formed in a fitting structure. 12. The heat insulating member in which the thickness of the central portion in the axial direction is thinner than the thickness of the end portion thereof is divided into two in the axial direction at the thin portion of the central portion, and a fitting structure is formed at the central portion of the thin thickness. It is formed, The metal vapor laser apparatus of Claim 2 or 3 characterized by the above-mentioned. 13. The heat insulating member, wherein the thickness of the central portion in the axial direction is smaller than the thickness of the end portion of the heat insulating member, wherein another heat insulating member is coaxially arranged on the outer periphery of the end portion of an integral heat insulating member having a uniform thickness. It is formed, The metal vapor laser apparatus of Claim 2 or 3 characterized by the above-mentioned. 14. The heat insulating member, wherein the thickness of the central portion in the axial direction is smaller than the thickness of the end portion thereof, has a thicker heat insulating member with a tapered outer periphery of the end portion, and the tapered heat insulating member and the thinner heat insulating member. 4. The metal vapor laser device according to claim 2, wherein the metal vapor laser device is formed by butting. 15. The heat insulating member in which the thickness of the central portion in the axial direction is thinner than the thickness of the end portion thereof, the outer circumference of the end portion of the thick heat insulating member is tapered, and the tapered heat insulating members are abutted to each other. The metal vapor laser device according to claim 2 or 3, characterized in that. 16. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of its end portion, the heat insulating member is divided into three in the axial direction, and 5. The metal vapor laser device according to claim 4, wherein a heat insulating member having a small inner thickness is arranged on the outer peripheral side of a central portion in the axial direction of the discharge tube and has a butt structure with the heat insulating members having a thicker thickness at both ends. . 17. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of the end portion, the heat insulating member located at one end portion and having a large thickness. And a thin heat insulating member located on the outer peripheral side of the central portion in the axial direction are integrated with each other, and the thin end of the heat insulating member of this integrated structure and the thick heat insulating member located at the remaining end are butted against each other. The metal vapor laser device according to claim 4, wherein the metal vapor laser device has a structure. 18. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of its end portion, the heat insulating member located at one end portion and having a large thickness. And a thin heat insulating member located on the outer peripheral side of the central portion in the axial direction are integrated into a structure, and the thin end of this integrated heat insulating member and the thick heat insulating member located at the remaining end are fitted together. The metal vapor laser device according to claim 4, wherein the metal vapor laser device has a structure. 19. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of its end portion, the heat insulating member is axially divided into three parts, 5. The metal vapor laser device according to claim 4, wherein a heat insulating member having a small inner thickness is arranged on the outer peripheral side of the central portion in the axial direction of the discharge tube to be fitted to the heat insulating members having a large thickness at both ends. . 20. The heat insulating member, wherein the inner circumferential length of the central portion in the axial direction of the discharge tube is longer than the inner circumferential length of the end portion thereof, wherein the heat insulating member has a uniform thickness inside the end portion of the heat insulating member. The metal vapor laser device according to claim 4, wherein another heat insulating member is coaxially arranged on the circumference. 21. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of the end portion thereof, the inner peripheral end portion of the thick heat insulating member is tapered. The metal vapor laser device according to claim 4, wherein the tapered heat insulating member and the heat insulating member having a small thickness are abutted against each other. 22. The heat insulating member, wherein the inner peripheral length of the central portion in the axial direction of the discharge tube is longer than the inner peripheral length of the end portion thereof, the inner peripheral end portion of the thick heat insulating member is tapered. 5. The metal vapor laser device according to claim 4, wherein the tapered heat insulating members are formed by abutting each other. 23. A discharge tube for heating and evaporating a metal source by a discharge energy in a gas to generate a metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer circumference of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, another heat insulating member is coaxially arranged on the outer peripheral side of the heat-resistant glass tube, and at a portion other than the central portion of the discharge tube, and these heat insulating members are provided at a tube wall temperature in the central portion of the discharge tube. Becomes extremely small,
In addition, the metal vapor laser device is provided with adiabatic characteristics for forming a tube wall temperature distribution in the discharge tube having a bimodal characteristic in which the tube wall temperature between the discharge tube central portion and the discharge tube end portion is maximized. . 24. A discharge tube for heating and evaporating a metal source by the discharge energy in a gas to generate a metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, at least one heat radiation plate is provided on the outer peripheral side of the heat-resistant glass tube and in a region other than the central portion of the discharge tube, the metal vapor laser device. 25. The metal vapor laser device according to claim 24, wherein the heat radiation plate is provided with a plurality of openings. 26. A discharge tube for heating and evaporating a metal source by gas discharge energy to generate metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer circumference of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, a heat absorber is provided on the inner surface of the metal laser tube main body located at the center of the discharge tube in the vacuum heat insulating layer, and the cooling layer for removing the heat absorbed by the heat absorber is formed in the vacuum. A metal vapor laser device provided on the outer periphery of a heat insulating layer. 27. A discharge tube for heating and evaporating a metal source by gas discharge energy to generate a metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, a cooling layer is provided coaxially on the outer periphery of the vacuum heat insulating layer,
The cooling layer is separated into a plurality of chambers by a plurality of metal flanges provided in the axial direction of the metal laser tube, and a cooling medium for cooling the cooling layer compartment located in the axial center of the discharge tube. A metal vapor laser device characterized in that a temperature is made lower than a temperature of a cooling medium to be flown into cooling layer compartments located on both sides thereof. 28. A discharge tube for heating and evaporating a metal source by gas discharge energy to generate metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, a cooling layer is provided coaxially on the outer periphery of the vacuum heat insulating layer,
The cooling layer is separated into a plurality of chambers by a plurality of metal flanges provided in the axial direction of the metal laser tube, and one of the chambers is located in the central portion of the discharge tube in the axial direction and the heat-resistant glass tube and the metal. Formed in a region surrounded by a laser tube made of laser, the temperature of the cooling refrigerant in the cooling layer compartment located in the axial center of the discharge tube, the cooling refrigerant flow to the cooling layer compartments located on both sides of it. A metal vapor laser device characterized in that the temperature is lower than the temperature. 29. A discharge tube for heating and evaporating a metal source by discharge energy in gas to generate metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, a spring-shaped plate made of a good heat conductor is brought into contact with the outer peripheral surface of the heat-resistant glass tube and the inner peripheral surface of the metal laser tube at a portion located in the central portion of the vacuum heat insulating layer in the axial direction of the discharge tube. A metal vapor laser device characterized by being provided as described above. 30. The metal vapor laser device according to claim 29, wherein the spring-shaped plate is formed in a ring shape. 31. The bulk density of the heat insulating member located at the central portion of the discharge tube in the axial direction is made smaller than the bulk density of the heat insulating member located at the end portion thereof to dissipate heat from the central portion of the discharge tube in the axial direction. 6. The structure according to claim 5, which is accelerated from the end.
The described metal vapor laser device. 32. The metal according to claim 5, wherein a plurality of other heat insulating members having a higher thermal conductivity than the heat insulating member are arranged alternately with the heat insulating member at an axial center portion of the heat insulating member. Steam laser device. 33. A discharge tube for heating and evaporating a metal source by the discharge energy in a gas to generate a metal vapor and forming a laser medium made of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, a heat-generating body coated with electric insulation is arranged on a portion of the outer peripheral surface of the heat-resistant glass tube except at least a central portion in the axial direction of the discharge tube, and the heat-resistant glass tube is heated by the heat-generating body. A metal vapor laser device characterized by the above. 34. A discharge tube for heating and evaporating a metal source by gas discharge energy to generate metal vapor and forming a laser medium composed of the metal vapor, and a discharge tube coaxially provided on the outer periphery of the discharge tube. A heat-insulating member, a heat-resistant glass tube coaxially provided on the outer circumference of the heat-insulating member, and a metal laser tube coaxially provided on the outer circumference of the heat-resistant glass tube to form a vacuum heat-insulating layer In the vapor laser device, at least a portion of the outer peripheral surface of the discharge tube except an axial center portion of the discharge tube, an electrically insulating coated heating element is disposed,
A metal vapor laser device characterized in that the discharge tube is heated by the heating element.