JPH01194482A - Gas laser oscillating apparatus - Google Patents

Abstract

PURPOSE:To enhance efficiency of laser beam oscillation, by a structure wherein at least one of electrodes for discharge is formed by an electrode pipe with a bore of the substantial same size as that of a capillary section, so as to be concentric with the capillary section. CONSTITUTION:In a discharge tube 12, the bore of the middle section along longitudinal direction is made small to form a capillary section 13. An electrode pipe 18 constituting a hollow electrode is in contact with one end of the capillary section 13. This electrode pipe 18 is formed by a thin wall stainless pipe with a bore size (d) of about 2.4-8mm. In this connection, the bore size (d) is preferably either the same as that of the capillary section 13 or somewhat larger than that thereof. And, edge section on the side of an anode 15 of the electrode pipe 18 is covered with a fitting edge 19 so as not to be exposed in the discharge tube 12. Thus, the edge section is prevented from being exposed, and thereby generation of discharge is prevented from being biased at the edge section, so that the discharge is uniformly generated throughout the inner peripheral surface of the electrode pipe 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser oscillation device that uses, for example, Ar gas as a laser gas medium.

(Prior Art) For example, there is a gas laser oscillation device that uses Ar gas as a laser gas medium.
In order to increase the current density flowing through the gas medium sealed within the discharge tube, the inner diameter of the discharge tube is made small.

Such a gas laser oscillation device is configured as shown in FIG. 6, for example. A discharge tube 1 constituting the main body of the device has an inner diameter of several mm at its longitudinal center and is provided with a thin tube portion 2. The material is electrically insulating and has high thermal conductivity, such as beryllia (Bed).
) is formed by. A cooling section 3 is provided on the outer periphery of the thin tube section 2, and is configured to be water-cooled or air-cooled.

A first volume part 5 is formed on one end side of the thin tube part 2, and a first volume part 5 is formed in which the anode 4 is disposed. The formed anode 4 is provided. In addition, the first volume part 5
Further, a transmission window 6 is provided on the end side.

On the other hand, on the other end side of the thin tube section 2, a second volume section 8 in which a cathode 7 is provided is provided. The shade above! il!
7 is an impregnated cathode, for example, a direct heating type in which a porous tungsten sintered body is impregnated with a barium compound;
It is formed in a coil shape concentric with the thin tube section 2. Furthermore, a transmission window 8a is provided further toward the end of the second volume portion 5. Here, on the outside of the two transmission windows 6.8a provided at both ends of the discharge tube 1, mirror bodies (not shown) are provided facing each other to form an optical resonator.

A DC or AC heater power source 9 is connected to the cathode 7.
is connected to the anode 4 and the cathode 7, and a DC power supply lO is connected to the anode 4 and the cathode 7.
A resistor section 11 is provided between the picture electrodes 4 and 7 to stabilize the discharge between the picture electrodes 4 and 7.

In order to oscillate laser light, the gas laser oscillation device configured in this way first heats the cathode 7 with a current from the heater power supply 9, and then uses the DC power supply 10 to heat the cathode 7 between the anode 4 and the cathode 7. By applying a voltage to and causing a discharge current of several amperes to flow, the gas medium is excited and laser light is generated. By performing the discharge continuously in this manner, laser light is continuously generated and oscillated between mirror bodies (not shown).

However, since the impregnated cathode 7 constructed as described above is made of a high-melting point metal material, it is difficult to weld during manufacture, and its strength is low and its lifespan is not long. In addition, it is expensive because it is a porous tungsten sintered body.
Furthermore, since it is of the thermionic emission type, a heater power source 9 is required, which complicates the structure of the device and increases the manufacturing cost of the device.

(Problems to be Solved by the Invention) As mentioned above, the gas laser oscillation device requires a heater power source because its cathode is of the thermionic emission type, which complicates the structure of the discharge tube. Since it is formed of a porous tungsten sintered body or the like, it is expensive, has low strength, and is difficult to weld, increasing manufacturing costs.

This invention was made in view of the above circumstances, and it reduces manufacturing costs by providing a high-strength and inexpensive cathode, and also improves laser beam oscillation by forming the cathode into a shape similar to that between thin tubes. An object of the present invention is to provide a gas laser oscillation device that can improve efficiency.

[Structure of the invention]

(Means for Solving the Problems) This invention forms a narrow tube part by reducing the diameter of the middle part in the longitudinal direction of the discharge tube, and provides discharge electrodes on both ends of this narrow tube part, and A power source is connected to the electrodes, an optical resonator is formed by mirror bodies facing each other with the discharge tube in between, and at least one of the discharge electrodes is formed with an electrode pipe having an inner diameter substantially the same as the inner diameter of the thin tube portion. By providing the gas laser oscillation device concentrically in the thin tube portion, the gas laser oscillation device is less expensive and stronger than conventional structures, and is also compact and capable of highly efficient laser beam oscillation.

(Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The discharge tube 12 shown in the figure is filled with a laser gas medium such as Ar gas at a predetermined pressure.
The inner diameter of the middle part in the longitudinal direction is reduced to form a narrow tube part 1.
3 is formed.

A first volume portion 14 is provided at one end of the thin tube portion 13.
is formed in the first volume part 14, and an anode 1 is formed in the first volume part 14.
5 is provided. The anode 15 is formed into an annular shape having an inner diameter larger than the inner diameter of the thin tube portion 13, and its center is provided to coincide with the center of the thin tube portion 13. moreover,
A transmission window 16 is provided in the first volume portion 14 located outside the anode 15 . Further, a first cooling section 17 is provided on the outer circumference of the thin tube section 13, and this first cooling section 17 cools the thin tube section 13 from the outside by air cooling or water cooling.

On the other hand, an electrode pipe 18 constituting a hollow electrode is brought into contact with the other end of the thin tube section 13, as will be described later.

This electrode pipe 18 has an inner diameter dimension d of approximately 2.4 to 8 m.
It is formed of a thin rR stainless steel pipe with a longitudinal dimension of about 50 to 100 mz.

Note that the dimension d is preferably the same as or slightly larger than the inner diameter of the thin tube portion 13. The connecting portion at the end of the electrode pipe 18 is fitted onto the outer periphery of a connecting edge 19, which is an extended end of the thin tube portion 13. In other words, positive I of Electrode Noku Eve 18!
iI! The edge portion on the 15 side is covered by the coupling edge 19 so as not to be exposed inside the discharge tube 12.

By preventing the edge portions from being exposed in this manner, the discharge is prevented from being biased toward the edge portions, and a uniform discharge can be generated over the inner circumferential surface of the electrode nozzle 18.

Further, a second cooling section 2 is provided on the outer circumference of the electrode pipe 18.
0 is provided, and is configured similarly to the first cooling section 17 described above.

Further, a second volume portion 21 is provided at the other end of the electrode pipe 18, and a transmission window 22 is provided in the second volume portion 21.

Two mirror bodies (not shown) are provided facing the two transmission windows 16 and 22, that is, with the discharge tube 12 in between, to form an optical resonator. Of the two mirror bodies that make up this optical resonator, one has a low reflectance so that it transmits laser light with a predetermined output or more, and the other mirror has a high reflectance. .

Further, a DC power supply 23 provided outside the discharge tube 12 is connected between the anode 15 and the electrode pipe 18 forming the cathode, and a discharge A resistor section 24 is provided to stabilize the .

When a gas laser oscillator configured as described above oscillates a laser beam, a voltage is applied from the DC power supply 23 to generate a discharge between the anode 15 and the electrode pipe 18 through the thin tube section 13. be done. This discharge excites the gas medium and generates laser light. This laser light is continuously amplified between the optical resonators (not shown) above,
When the output exceeds a predetermined value, the light is emitted from one of the mirror bodies of the optical resonators.

At this time, glow discharge is generated within the electrode vibrator 18, and laser light is generated under substantially the same conditions as within the thin tube section 13. In other words, in the conventional structure, the part where the cathode is provided is a volume part, and effective generation of laser light cannot be expected in this part, but the electrode pipe 18 is more effective than the cathode in the conventional structure. A high electron temperature can be obtained even when applying a low voltage. In other words, the negative glow discharge generated on the inner wall surface of the electrode pipe 18 effectively excites the laser gas medium, allowing highly efficient gas laser oscillation.

Furthermore, the electrode pipe 18 is formed using a commercially available stainless steel pipe, etc., and since the electrode does not require heating, a heating power source is not required, and the output is higher than that of the conventional structure. Therefore, it is possible to obtain a gas laser oscillation device that can reduce production costs.

A second embodiment of the present invention will be described below with reference to FIG. A discharge tube 25 shown in the figure is filled with a laser gas medium at a predetermined pressure, and a narrow tube portion 26 is formed by reducing the inner diameter at a midway portion in the longitudinal direction.

Here, the discharge tube 25 is made of beryllia (Bed), and a cooling section 27 is provided on the outer periphery of this narrow tube section 26. Further, a first electrode pipe 28 is brought into contact with one end of the thin tube portion 26, and the first electrode pipe 28 is formed of a thin stainless steel pipe. The inner diameter of this first electrode pipe 28 is approximately 2.4 to 8 m.
m, and the vibe length is approximately 50 to 100111 JI. Here, the inner diameter of the first electric four pipe 28 is preferably the same as or slightly larger than the inner diameter of the thin tube portion 26. Further, the edge of the joint portion of the first electrode pipe 28 to the thin tube portion 26 is attached so as not to be exposed to the inner wall, thereby preventing uneven discharge. A cooling section 29 is provided on the outer periphery of the first electrode pipe 28.

Furthermore, a first volume part 30 is provided on the end side of this first volume part 30, and a transmission window 31 is provided in this first volume part 30.

On the other hand, a second electrode pipe 3 is provided at the other end of the thin tube section 26.
2 is provided. This second electrode pipe 32 has the same structure as the first electrode pipe 28, and a cooling section 3B is provided on the outer circumference of the second electrode pipe 32. A second volume part 34 is provided at the end of the second electrode pipe 32.
4 is provided with a transmission window 35.

Wiring from a DC power source 36 is connected to the first electrode pipe 28 and the second electrode pipe 32, for example, the first electrode pipe 28 is connected to the anode side, and the second electrode pipe 32 is connected to the anode side. 32 is set on the cathode side. Also, the first electrode pipe 28 on the anode side and the DC power source 36
A resistor section 37 is provided between the picture electrodes 28 and 32 to stabilize the discharge between the picture electrodes 28 and 32.

With this configuration, if impurities are added to the inner circumferential surface of the second electrode pipe 32 by sputtering or the like and it becomes impossible to uniformly generate a negative glow,
The connection between the cathode side and the anode side of the DC power supply 36 is changed, and the first electrode pipe 28 is placed on the cathode side, and the second electrode pipe 32 is placed on the cathode side.
By setting the first electrode pipe 28 on the anode side, the first electrode pipe 28 which is used as an anode and has no impurities attached thereto can be used as a cathode. Therefore, the life span can be significantly extended compared to the conventional structure, and the light can be oscillated with high efficiency over a long period of time.

Furthermore, the DC power source 36 can also be an AC generating power source.

A third embodiment of the present invention will be described below with reference to FIG. In the middle part of the discharge tube 38 shown in the figure, there is a first
and a second capillary section 39,40. These thin tube portions 39 and 40 are formed to have the same dimensions and are arranged coaxially one after another, and cooling portions 41 and 42 are provided on the outside, respectively. A first electrode pipe 43 is provided between the first and second thin tube portions 39,40. The edge of the end of the first electrode pipe 43 is connected to the end of the thin tube portion 39, 40 so as not to be exposed to the inner peripheral surface side. A cooling section 44 is provided on the outer periphery of the first electrode pipe 43 .

Further, second and third electrode pipes 45,46 are provided at the outer ends of the first and second thin tube portions 39,40, respectively.
is provided. These second and third electrode pipes 45 and 46 are connected to the first and second thin tube portions 3, respectively.
and 40, and the connecting edge of each electrode pipe 45, 46 is connected to the three thin tube portions, 40, and
It is configured so that it is not exposed to the inner circumferential surface side by an edge (not shown).

Here, the inner diameters of the first to third electrode pipes 43, 45, 46 are preferably the same as or slightly larger than the inner diameter of the thin tube portion 39, 40. Furthermore, cooling portions 47.48 are provided on the outer peripheries of the second and third electrode pipes 45.46, respectively. Further, first and second volume portions 49.50 are provided on the outer sides of the second and third electrode pipes 45.46, respectively.
50 is provided with transmission windows 51 and 52. Here, the first, second and third electrode pipes 43, 45
．． 46 are both made of thin stainless steel pipes.

A first DC power source 53 is connected to the first and second electrode pipes 43 and 45, and there is no discharge between the first DC power source 53 and the second electrode pipe 45. A stabilizing first resistance section 54 is provided.

In addition, the first electrode pipe 43 and the third electrode pipe 4
6 is connected to a second DC power supply 55, and a second resistance section 56 is provided between the second DC power supply 55 and the third electrode pipe 46 to stabilize the discharge. There is.

A laser gas medium such as Ar gas is sealed inside the discharge tube 38 configured in this manner at a predetermined pressure.

With this configuration, the reduced diameter portion of the discharge tube 38 is extended and a plurality of electrode portions are provided, so that the efficiency of laser beam oscillation can be improved and the device can be made smaller. can.

In this embodiment, the second and third electrode pipes 45 and 46 on the outside are configured to generate discharge between each of the first electrode pipes 43, and the two laser devices are connected continuously. However, the present invention is not limited to this, and includes, for example, a configuration in which three laser devices are consecutively provided. In other words, a structure in which anodes and cathodes of paired electrodes are provided alternately and a plurality of pairs of electrodes are provided in succession is also included.

〔Effect of the invention〕

As explained above, according to the present invention, by forming at least one of the electrodes with an electrode vibrator and generating discharge through the inner peripheral surface of the electrode, the current density can be improved compared to the conventional structure. High output can be obtained even when voltage is applied, and laser light can be oscillated with high efficiency. Furthermore, it is possible to provide a gas laser oscillation device that is small, has a large output, and can reduce production costs.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a side cross-sectional view showing a schematic structure of a gas laser oscillation device, and FIG. 2 is a structure of a connecting portion between a thin tube portion and an electrode pipe. 3 is a perspective view showing the shape of the electrode pipe, FIG. 4 is a side sectional view showing the schematic structure of a gas laser oscillation device according to the second embodiment of the present invention, and FIG. 5 is a perspective view showing the shape of the electrode pipe. FIG. 6 is a side sectional view showing a schematic structure of a gas laser oscillation device according to a third embodiment, and FIG. 6 is a side sectional view showing a schematic structure of a conventional gas laser oscillation device. 12...Discharge tube, 13...Thin tube part, 15...Anode (discharge electrode), 18...Electrode vibe (discharge electrode)
, 23...DC power supply (power supply). Applicant's representative Patent attorney Takehiko Suzue No. 11 IJ No. 2 d- No. 30 No. 60

Claims (1)

[Claims] a discharge tube in which a gas laser medium is sealed at a predetermined pressure; a narrow tube portion in which the diameter of the discharge tube is reduced in the middle in the longitudinal direction;
A gas laser oscillation device that includes discharge electrodes provided on both end sides of the thin tube section, a power source provided on these discharge electrodes, and an optical resonator formed by mirror bodies facing each other with the discharge tube in between. A gas laser oscillation device characterized in that at least one of the discharge electrodes is formed of an electrode pipe having an inner diameter substantially the same as the inner diameter of the thin tube portion and concentrically abuts an end of the thin tube portion.