JP2862058B2 - Laser oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillator.

[0002]

2. Description of the Related Art FIG. 14 is a perspective view showing a typical configuration of a conventional three-axis orthogonal laser oscillator disclosed in Japanese Patent Application Laid-Open No. 60-254684. FIG. 15 is a cross-sectional view of the laser oscillator of FIG. 14 as viewed from above. In the figure, 1 is a laser beam, 2 is an optical axis of the laser beam, 3 is a laser medium gas, 4
Is a discharge electrode, 6 is a blower, 7 is a flow of a laser medium gas,
Reference numeral 8 denotes a heat exchanger, 11 denotes a duct for circulating the laser medium gas 3, and 12a, 12b, 12c, and 12d denote laser light reflecting means. The laser medium gas 3, the discharge electrode 4, the blower 6, the heat exchanger 8 , The duct 11 is formed inside the housing 10.

FIG. 16 is a perspective view of a partial cross section showing a conventional discharge electrode 4. 13 is a dielectric, 14 is a metal electrode covered with the dielectric 13, 15 is a passage of cooling water flowing inside the metal electrode 14 and cooling the discharge electrode 4, and 16 is a metal electrode 14
And the discharge electrode 4 is configured as described above. 5 is an AC voltage power supply applied to the metal electrode 14,
Reference numeral 9 denotes a discharge generated between the dielectrics 13.

Next, the operation will be described. The casing 10 is filled with a laser medium gas 3 and circulated by a blower 6 so as to pass between a pair of discharge electrodes 4.
The laser medium gas 3 is, for example, in the case of a carbon dioxide laser,
A mixed gas containing carbon dioxide, nitrogen and helium is common. A discharge 9 is generated between the discharge electrodes 4 by applying an AC voltage to excite the laser medium gas 3, and a population inversion in which the distribution density of so-called high energy levels of atoms is larger than that of low energy levels. Generate The laser medium gas in which the population inversion has occurred emits light and is reflected and amplified by the laser reflecting means 12a, 12b, 12c and 12d. In particular, the laser beam reflecting means 12a is configured to transmit light. In FIG. 14, four laser light reflecting means are used in a Z-type folded type laser oscillator, but another resonator configuration (the number of laser light reflecting means is two or more) may be adopted. The amplified light is taken out as laser light 1 from the laser reflecting means 12a. The excited high-temperature laser medium gas 3 passes through the heat exchanger 8 and is cooled and circulated again.

[0005] The discharge electrode 4 is disposed so that a discharge is formed perpendicularly to the flow direction with the laser medium gas flow 7 interposed therebetween. The dielectric 13 is a high dielectric such as glass or ceramics. When the AC voltage 5 is applied to the metal electrode 14, a dielectric discharge 9 is generated between the dielectrics 13 of the opposing discharge electrodes 4. The insulator 16 is formed so as to cover the dielectric 13 with a part of the surface on the discharge surface side of the dielectric 13 being exposed, and is used to suppress discharge with peripheral members (for example, the housing 10). I have. The insulator 16 is, for example, a silicon-based or Teflon-based resin, and has a lower dielectric constant than the dielectric 13. The surface of the dielectric 13 is excited,
Since the high-temperature laser medium gas 7 is circulating, the cooling water 15 flows through the metal electrode 14 to indirectly cool the dielectric 13. Although not described in detail in the figure, the cooling water flows through the cooling water passage 15 and is configured to circulate through a fan cooler, a compressor, or the like.

[0006]

The conventional laser oscillator is constructed as described above. Since the laser medium gas 3 is excited by the discharge 9, the laser medium gas flows in the direction 7 of the laser medium gas as shown in FIG. A gradient occurs. Since the refractive index is generally a function of temperature, the temperature gradient produces a refractive index distribution. Since light travels in the direction of higher refractive index, the same situation occurs as if a prism was inserted into the resonator, and light starts to resonate at an oscillation axis different from the set optical axis 2. . Also, since the temperature gradient is proportional to the discharge power, increasing the laser beam oscillation output increases the discharge power,
The temperature gradient also increases. As a result of the change, when the laser light reflecting means is fixed, the oscillation axis changes as shown in FIG. Here, it should be noted that the optical axis is a in FIG. 18 when there is no temperature gradient, and generally indicates an axis connecting the centers of the respective laser reflecting means. , The axis to amplify. Due to the above-mentioned change, there is a problem that when processing or measurement for changing the laser output is performed, a position shift or an angle shift occurs, and it is difficult to perform accurate measurement or accurate processing.

The present invention has been made to solve the above problems, and has as its object to obtain a stable laser oscillator in which the characteristics of a laser beam do not change due to a change in laser output.

[0008]

In a laser oscillator according to the present invention, a discharge electrode has an electrode tube for applying an AC voltage for generating a discharge, a cooling passage for cooling the discharge electrode, and a laser light beam. The laser medium gas is divided in the axial direction and flows between the divided discharge electrodes so that the flow of the laser medium gas becomes a counterflow between the respective discharge electrodes, and each electrode tube has a single cooling passage. It has a single discharge electrode which is connected to the passage connecting means and a wiring for sharing an AC voltage, and has a single discharge electrode, and the upstream end of the laser medium gas of each discharge electrode is alternately arranged with the optical axis of the laser light interposed therebetween. It is formed on the opposite side.

The discharge electrode has an electrode tube for generating a discharge and a cooling passage for cooling the electrode, and the electrode tube of the discharge electrode has a central axis for dividing a flow of the laser medium gas. Are bent in parallel with each other, so that the flow of the medium gas is opposed to each other at the bent portion of the electrode tube.

Further, the bent portion of the electrode tube is covered with an insulator, and is configured to be thinner than the electrode tube of the discharge portion for generating a discharge.

The discharge electrode has an electrode tube for generating a discharge, the electrode tube has a projection on a discharge surface, and the projection is divided and arranged in the optical axis direction of the laser beam. The flow of the laser medium gas passing between the projected portions of the discharge electrodes is formed so as to be opposed to each other between the projected portions, and the portion other than the projected portion of the electrode tube is covered with an insulator. It was done.

Further, the discharge electrode has a dielectric material having a conductor disposed on the back surface on the discharge generating side so as to generate a discharge, and the conductor is divided in the optical axis direction of the laser beam, and is divided. The flow of the laser medium gas passing between the discharge electrodes corresponding to the conductors is such that the conductors are opposed to each other.

[0013]

Since the laser oscillator according to the present invention is configured to correct the deviation of the oscillation axis caused by the temperature gradient of the laser medium gas, it is possible to correct the positional deviation of the laser beam caused by the intensity of the discharge power. .

[0014] Further, since it is configured so that the displacement of the laser beam caused by the strength of the discharge power can be corrected and the discharge can be divided by integrating the discharge electrodes, the number of pipes and wirings inside the housing increases. Without this, a highly reliable laser oscillator can be obtained.

Further, the turbulence and swirl of the laser medium gas caused by the gas flow intersecting in the discharge region of the discharge electrode can remove the adverse effect on the laser beam, and can correct the displacement of the laser beam caused by the discharge power.

In addition, the deviation of the oscillation axis caused by the laser medium gas can be corrected by the combination of the units, and the anisotropy of the laser beam generated in the axial direction of the laser medium gas and the axial direction of the discharge is improved. A uniform beam with no directivity can be generated.

[0017]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG.
1 is a perspective view showing a laser oscillator according to one embodiment of the present invention. FIG. 2 is a sectional view of the laser oscillator of FIG. 1 as viewed from above. The difference from the conventional laser oscillator is that the discharge electrode 4, the blowers 6a and 6b, the heat exchangers 8a and 8b, and the ducts 11a and 11b are divided at the center of the casing 10 in the optical axis direction and left and right opposite to the optical axis. And the laser medium gases 7a and 7b are flowing so as to face each other. The other configuration is the same as that of the conventional laser oscillator, and will not be described. The discharges 9a and 9b generated by the discharge electrode 4 are generated by being divided at positions where the blower and the like are divided, and the optical axis position 2 where laser oscillation is generated is located downstream of the respective discharges 9a and 9b. As a result, the discharge electrode 4 is integrally formed.

FIG. 3 is a detailed view showing a partial cross section of the discharge electrode 4 shown in FIG. In the figure, 13a, 13
“b” is a dielectric that is divided at least into two in the laser oscillation optical axis direction and shifted in the gas flow direction. The shift amount is formed so that the distance from the upstream end of the discharge to the optical axis is the same. The dielectrics 13a and 13b are provided so as to face the respective dielectrics. 9a and 9b are discharges generated by applying an AC voltage 5 to the electrode tube. Since the metal electrode 14 and the insulator 16 covered by the dielectrics 13a and 13b have the same configuration as the conventional one, the description is omitted.

Next, the operation of the first embodiment will be described.
Since the operation of the laser oscillator is the same as before,
Here, it is omitted. As shown in FIG. 1 and FIG.
a, 6b, heat exchangers 8a, 8b, ducts 11a, 11b
Are divided into two with respect to the discharge electrode 4 and are arranged symmetrically to each other, so that the laser medium gases 7a and 7b flow in the counterflow in the discharge space generated by the discharge electrode 4. In the discharge space, a temperature distribution is generated in the flow direction of the laser medium gas, but the gradient of the temperature distribution reverses when the flow becomes countercurrent. The problem of the laser beam oscillation axis being bent by the distribution of the refractive index caused by the temperature distribution was explained in the problem of the prior art, but the reversal of the inclination reverses the bending of the oscillation axis and corrects the displacement of the oscillation axis. It is possible to

As described above, the example in which the discharge zone is divided into two sections has been described. However, the same effect can be obtained when the discharge zone is divided into multiple sections. That is, the bending of the laser oscillation axis can be decomposed into a component that moves in parallel and a component of the angle depending on the shape of the curvature of the laser light reflecting means 12a, 12b, 12c, and 12d. It is possible to cancel by setting the number of divisions to an even number. The angle component disappears as the number of divisions increases. 1 and 2
When the number of turns is three as shown in FIG.
In any case, the number of divisions of the optical axis is six, and the angle component is so small that it can be ignored. FIG. 4 shows changes in the oscillation axis when the laser output is increased (when the temperature gradient is increased) in the case of two divisions, as indicated by 2a → 2b → 2c. In the figure, the change of the oscillation axis is greatly described so that the difference can be recognized. However, in practice, the amount of parallel deviation is very small and does not cause any problem in actual use. Since the amount of angular displacement is much smaller than that of the conventional example (FIG. 18), even if the beam is propagated over a long distance, the positional displacement of the beam is very small.

Appl. Phys. 22 (1989) 1
As reported in 835-1839, in a laser oscillator in which the flow of the laser medium gas, the direction of discharge, and the optical axis cross each other perpendicularly, the optical axis of the laser light may be set at the downstream end of the laser medium gas of the discharge. Many. Since the laser oscillation gain is highest at the downstream end of the discharge, it is used for efficiently extracting the laser output. In addition, when the pulse response at the time of pulse oscillation is required rather than taking out the laser output efficiently, the optical axis is moved from the downstream end of the discharge gas toward the center of the discharge. The reason for setting the optical axis on the upstream side of the discharge is determined by the rise time of the pulse: τ is τ = X / V X: distance from the upstream end of the discharge to the optical axis V: laser medium gas flow rate inside the discharge The only way to make the pulse rise faster is to improve the performance of the blower or move the optical axis to the upstream side of the discharge. As described above, the optical axis position can be changed depending on the required items, but the distance (X in FIG. 2) from the gas upstream end of the discharge to the optical axis is the same at each of the divided discharge positions. Set. The discharge 9a,
9b may have an overlapping portion when viewed from the optical axis direction,
It is not necessary to arrange so that it may overlap. The design condition for minimizing the deviation of the laser beam is that the distance from the upstream end of the discharge gas to the optical axis is the same, but the distance to the optical axis differs within the range of manufacturing errors. The same effect can be obtained. Furthermore, if the upstream end of the laser medium gas of the discharge electrode is formed alternately on the opposite side with respect to the optical axis of the laser light, the displacement of the laser light beam is very small as compared with the conventional method.

With the above configuration, the discharge, the optical axis, and the gas flow are set so that the temperature gradient generated by the laser output is reversed in the optical axis direction. There is an effect that the positional deviation can be corrected.

FIG. 5 shows an electrode tube in which a dielectric material of the discharge electrode and a metal electrode are integrated as a means for generating a discharge by dividing the discharge electrode. 5
Is an AC power supply, 13a and 13b are dielectrics, 14a and 14b
Is a metal electrode, 15a and 15b are cooling water passages for cooling the metal electrodes, 18 is a wiring for electrically connecting the metal electrodes 14a and 14b, and 19 is a cooling water passage 1 inside the metal electrode 14.
A bypass connecting 5a and 15b, 20 is an electrode tube combining a metal electrode and a dielectric. The dielectric 13 is, for example, glass or ceramics, and covers the metal electrode 14 by coating or thermal spraying. The bypass 19 may be a pipe with a hose or a block having a cooling water passage. FIG. 5 shows the structure of the electrode tube for generating two divided discharges. However, in the case of three or more divided portions, only the number of the electrode tubes 20 and the number of the bypasses 19 and the wires 18 are increased. Also, the opposite electrode tubes that generate the discharge are not shown.

Since the plurality of electrode tubes are electrically connected, all of the divided discharges occur in the same phase. Since the discharge is performed in the same phase, there is no influence from the adjacent discharge, and a very stable discharge can be obtained. Further, since a plurality of discharges can be divided by one pair of discharge electrodes, the number of members inside the housing 10 does not increase, and the degree of freedom of the arrangement method based on the insulation distance is extremely high. Also,
Since the divided electrode tubes connect both electricity and cooling water inside the discharge electrode, the number of wires and pipes to the discharge electrode remains the same as before, and the number of joints inside the housing does not increase,
Water leakage and discharge between wiring and between wiring and members can be suppressed as much as possible, and there is an advantage that reliability as a laser oscillator is enhanced.

Embodiment 2 FIG. FIG. 6 shows another example of an electrode tube in which a dielectric material of a discharge electrode and a metal electrode are integrated as a means for generating a discharge by dividing a discharge electrode. 5 is an AC power supply, 13 is a dielectric, 14 is a metal electrode, 15 is a cooling water passage for cooling the metal electrode, 20 is an electrode tube combining the metal electrode and the dielectric, 21 is a metal electrode bent, and This is a bent portion that shifts the central axis of the electrode in parallel. FIG. 6 shows the structure of an electrode tube for generating a two-part discharge, but FIG.
In the case of division or more, only the bending portion is increased. In place of the bypass of the first embodiment, a member used for a metal electrode may be used and connected by welding or the like. Since the connection is made using the same members as the metal electrodes, no wiring is required and electrical conduction is achieved. The dielectric 13 also covers the bent portion of the metal electrode, and the bent portion also generates discharge. When it is desired to gain a discharge area, such a configuration is adopted. Other effects are the same as those of the first embodiment.

Embodiment 3 FIG. FIG. 7 shows in detail another embodiment of an electrode tube in which a dielectric material of a discharge electrode and a metal electrode are integrated as means for generating a discharge by dividing a discharge electrode. 5 is an AC power supply, 13 is a dielectric, 14 is a metal electrode, 15 is a passage for cooling water for cooling the metal electrode, 20 is an electrode tube combining the metal electrode and the dielectric, 22 is a metal electrode bent, and This is a bent portion that shifts the central axis of the electrode in parallel. The bent portion 22 is thinner than the metal electrode 14 and has a structure in which the discharge electrode is covered with the insulator 15 so as not to be exposed on the surface. In the figure, the structure of the electrode tube for generating a two-part discharge is shown. However, in the case of three or more parts, only the number of bent portions is increased. Regardless of whether or not the dielectric 13 covers the bent portion of the metal electrode, no discharge occurs because the bent portion is covered with the insulator. At the bent portion, the cooling water passage 15 also becomes narrower at the same time as the bent portion, and the pressure loss of the cooling water increases. However, when the discharge at the bent portion exerts an adverse effect (abnormal rise in gas temperature), such a case occurs. Configure. Other effects are the same as those of the first embodiment.

Embodiment 4 FIG. FIG. 8 shows in detail another embodiment of an electrode tube in which a dielectric material of a discharge electrode and a metal electrode are integrated as a means for generating a discharge by dividing a discharge electrode. 5 is an AC power supply, 13 is a dielectric, 14 is a metal electrode, 15 is a cooling water passage for cooling the metal electrode, 20 is an electrode tube combining the metal electrode and the dielectric, and 23a and 23b are discharge surfaces between the electrodes. It is a protruding portion protruding from The protruding portion may have a structure in which the metal electrode 14 has a protruding portion, or may protrude the dielectric itself. Except for the protruding portion 23, it is covered with the insulator 16,
It is not exposed on the surface of the discharge electrode. FIG. 8 shows the structure of the electrode tube for generating two-division discharge. However, in the case of three-division or more, only the number of protrusions 23 is increased. With the above configuration, the electrode tube becomes large, but since a bent portion between the electrodes is not required, the manufacturing cost is low,
The cooling water passage 15 is sufficiently large, and the pressure loss of the cooling water is eliminated. Other effects are the same as those of the first embodiment.

Embodiment 5 FIG. FIG. 9 shows the details of the dielectric of one discharge electrode as a means for generating a discharge by dividing the discharge electrode.
(A). 13 is a dielectric, and 24a and 24b are conductors formed on the back surface of the discharge surface of the dielectric. Dielectric 13
Has a metal electrode on the surface side of the conductor 24, and the conductors 24a and 24b are electrically connected to the metal electrode. The discharge is caused by the conductor 2 on the back of the dielectric.
4 is generated according to the shape of FIG. Since the conductor can be formed on the dielectric surface by printing or thermal spraying, it has a very high degree of freedom in shape, can generate various shapes of discharges, and can easily express a discharge with a large number of divisions. Other effects are the same as those of the first embodiment. In FIG. 9A, the conductors 24a and 24b are divided into two in the optical axis direction and are slid in the gas flow direction, and the conductor ends 27a and 27b are separated.
b is described as being coincident in the optical axis direction, but FIG.
As shown in (b), the ends 27a and 27b do not coincide with each other, and may enter the conductor 24 side or may be separated from each other. Although FIG. 9 shows only two parts as an example, a plurality of parts may be divided.

Embodiment 6 FIG. FIG. 10 is a perspective view showing a pair of discharge electrodes in detail.
In the figure, the same reference numerals are the same as those of the first embodiment, and the description is omitted. Reference numeral 25 denotes a partition provided at the boundary between the laser medium gases 7a and 7b facing the divided discharge.
The opposing laser medium gases collide at their boundaries, generate vortices and the like, causing convection loss and flow disturbance. The loss of convection causes a decrease in the flow rate of the laser medium gas, which hinders normal laser oscillation. In addition, the turbulence of the flow causes a local temperature rise, which makes the discharge unstable, deteriorates the positional accuracy of the laser beam, causes a local temperature rise of the discharge electrode, and destroys the discharge electrode. By providing the partition 25 at the boundary of the flow, there is an effect that the flow of the laser medium gas becomes smooth and a stable laser oscillator can be obtained. Since the partition 25 is installed near the discharge, an insulator is desirable. Further, the partition 25 needs a passage of a beam resonating inside the resonator, but it is more effective to configure the electrode portion so that there is no gap except for the beam passage.

Embodiment 7 FIG. FIG. 11 is a perspective view of a housing in which a pair of discharge electrodes 4, a blower 6, and a heat exchanger 8 are unitized. In the figure, the same reference numerals are the same as those in the related art, and the description is omitted. Reference numeral 26 denotes a unitized housing. FIG. 12 is a perspective view showing a method of combining the unitized housings 26 of FIG. 11 in two sets. FIG. 13 is a diagram showing an example of a case where four sets of unitized housings 26 are combined, showing only the relationship between the discharge electrode and the optical axis, and FIG. 13A is a diagram viewed from the optical axis direction. FIG. 13B is a view of FIG. 13A as viewed along the line AA ′, and FIG. 13C is a view of FIG. 13A as viewed along the line BB ′. A, b, c, and d after the respective codes indicate the first, second, third, and fourth units of the unitized housing, respectively. As shown in FIG. 12, when assembling a laser oscillator using two unitized housings 26, it is turned 180 degrees, and when using four as shown in FIG. 13, each is rotated 90 degrees. Let 2 × n
When using two, they are rotated and combined by 180 / n degrees. At both ends of the unitized and combined housing, blocks provided with mirror reflecting means are attached, vacuum shielded, and laser medium gas is sealed and circulated. The optical axes are installed so that the distance from the upstream end of the laser medium gas of the discharge in each unitized housing 26 coincides. The reason for setting the optical axis so that the distance from the upstream end coincides with that of the upstream end has already been described in the first embodiment, and a description thereof will be omitted here. The figure shows the case of a resonator having no fold, but if there is a fold, a pair of cases (directions of 18
It is only necessary that one of the folded optical axes (set by 0 °) is set so that the distance from the upstream end coincides.

The effect of this embodiment is that it is unitized, so that a laser oscillator having a different laser oscillation output can be supplied in a short period of time, and the same effect as that of the first embodiment can be obtained. Furthermore, the characteristics (circularity, order, etc.) of the laser beam may differ between the laser medium gas and the direction of the discharge, but when n is 2 or more, the axis of the laser medium gas and the axis of the discharge are interchanged. Because of the change, the anisotropy of the laser beam generated in the axial direction of the laser medium gas and the axial direction of the discharge can be eliminated, and a uniform beam having no directivity can be obtained.

Embodiment 8 FIG. In the first, second, third, fourth, fifth, sixth and seventh embodiments, the case where only one optical axis in the discharge space is present is shown. The same effect can be obtained by arranging any one of the optical axes so that the distance from the upstream end of the discharge coincides.

Embodiment 9 FIG. As a modification of the eighth embodiment, two optical axes are selected from a plurality of optical axes inside the discharge space, and the optical axes are arranged such that the center axis of the optical axes is equal to the distance from the upstream end of the discharge. Is also good. Further, axes obtained by dividing the distance between the two optical axes by an arbitrary distribution may be arranged so that the distances from the upstream end of the discharge coincide.

Embodiment 10 FIG. In the seventh embodiment, the unitized housing 26 is set at 180 degrees /
Although it is described that n units are combined, it is sufficient that at least two units are combined by being inverted by 180 degrees if only the positional deviation of the laser beam is corrected.

[0035]

Since the present invention is constructed as described above, it is possible to obtain a stable laser oscillator in which the characteristics of the laser beam are not changed by the laser output. Also,
Since the divided discharges have the same phase, a stable discharge can be obtained, and a plurality of discharges can be divided by a pair of discharge electrodes, so that the members of the housing can be saved, and the degree of freedom of the arrangement method based on the insulation distance and the like is high.

Further, since the connection of the electrode tubes is connected by the same member as the metal electrode, there is no need for wiring, and the bent portion is covered with the dielectric, so that a discharge area can be obtained.

Further, since no electric discharge occurs at the bent portion, adverse effects such as an abnormal rise in gas temperature can be prevented.

Further, the manufacturing cost is low, the passage of the cooling water is large, and the pressure loss of the cooling water can be prevented.

Further, the conductor has a high degree of freedom in shape, can generate discharges of various shapes, and can easily generate a discharge having a large number of divisions.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a laser oscillator according to an embodiment of the present invention.

FIG. 2 is a sectional view from above showing a laser oscillator according to an embodiment of the present invention.

FIG. 3 is a detailed view partially showing a structure of a discharge electrode of a laser oscillator according to an embodiment of the present invention;

FIG. 4 is a schematic diagram showing an oscillation axis of laser light according to one embodiment of the present invention.

FIG. 5 is a perspective view showing an electrode tube of a discharge electrode according to another embodiment of the present invention.

FIG. 6 is a perspective view showing an electrode tube of a discharge electrode according to another embodiment of the present invention.

FIG. 7 is a perspective view showing an electrode tube of a discharge electrode according to another embodiment of the present invention.

FIG. 8 is a perspective view showing an electrode tube of a discharge electrode according to another embodiment of the present invention.

FIG. 9 is a perspective view showing a dielectric of a discharge electrode according to another embodiment of the present invention.

FIG. 10 is a perspective view showing in detail a pair of discharge electrodes according to another embodiment of the present invention.

FIG. 11 is a perspective view showing a unitized housing according to another embodiment of the present invention so that the inside can be seen.

FIG. 12 is a perspective view showing two units combined so that the unitized housing shown in FIG. 11 is transparent and the inside can be seen.

13 is a sectional view taken along the optical axis, a sectional view taken along the line AA ', showing a positional relationship between the discharge electrode and the optical axis, and a sectional view taken along the line B-. It is sectional drawing of B '.

FIG. 14 is a perspective view showing a conventional laser oscillator.

FIG. 15 is a sectional view of a conventional laser oscillator viewed from above.

FIG. 16 is a perspective view showing a structure of a discharge electrode of a conventional laser oscillator in a partial cross section.

FIG. 17 is a temperature distribution generated in the direction of the flow of the laser medium gas.

FIG. 18 is a schematic diagram showing a change in oscillation axis depending on a laser output.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser light 2 optical axis 4 discharge electrode 5 AC voltage 6 blower 7 flow of laser medium gas 8 heat exchanger 9 discharge 13 dielectric 15 cooling passage 16 insulator 18 wiring 19 cooling passage connecting means 20 electrode tube 21 bent portion 22 Bent part 23 Projecting part 24 Conductor 25 Partition 26 Unit

Continuation of the front page (56) References JP-A-62-95884 (JP, A) JP-A-64-42875 (JP, A) JP-A-60-28288 (JP, A) JP-A-2-199893 (JP) , A)

Claims (5)

(57) [Claims] 1. An electric discharge generated between opposed discharge electrodes.
Direction and laser medium gas circulating through between the discharge electrodes
The laser medium gas by the discharge direction and the discharge.
The optical axis of the laser beam excited and generated crosses each other perpendicularly
In the laser oscillator configured as described above,
The electrode is an electrode that applies an AC voltage to generate a discharge
It has a cooling passage for cooling the tube and the discharge electrode,
Divided in the optical axis direction of the light,
The flow of the laser medium gas passing between the electrodes is between the discharge electrodes.
So that each electrode tube has one cooling passage.
To share AC voltage with cooling passage connecting means
And integrated discharge electrodes
The upstream end of the laser medium gas of each discharge electrode.
It is characterized by being formed on the opposite side alternately across the optical axis of the light
Laser oscillator. 2. A discharge is generated between the opposite discharge electrode
Direction and laser medium gas circulating through between the discharge electrodes
The laser medium gas by the discharge direction and the discharge.
The optical axis of the laser beam excited and generated crosses each other perpendicularly
In the laser oscillator configured as described above,
The electrodes consist of an electrode tube for generating electric discharge and a cold for cooling the electrodes.
A discharge passage, and the electrode tube of the discharge electrode is a laser medium gas.
Shift the central axis of the electrode tube in parallel to divide the flow
And the flow of the medium gas flows through the electrode tube.
It is especially noteworthy that the two
Laser oscillator. 3. The bent portion of the electrode tube is covered with an insulator.
And make it thinner than the electrode tube that generates the discharge.
The laser oscillator according to claim 2, wherein: 4. The method according to claim 1, wherein the discharge generated between the opposed discharge electrodes is
Direction and laser medium gas circulating through between the discharge electrodes
The laser medium gas by the discharge direction and the discharge.
The optical axis of the excited and generated laser beam crosses each other perpendicularly.
In a laser oscillator configured to
The electrode has an electrode tube for generating a discharge, and the electrode tube has a discharge tube.
The projection has a projection on the electrical surface, and the projection is in the optical axis direction of the laser beam.
Between the projected portions of the divided discharge electrodes
The flow of the laser medium gas through the
And the protruding part of the electrode tube
Other than that, it is covered with an insulator.
User oscillator. 5. A discharge generated between the opposed discharge electrodes
Direction and laser medium gas circulating through between the discharge electrodes
The laser medium gas by the discharge direction and the discharge.
The optical axis of the laser beam excited and generated crosses each other perpendicularly
In the laser oscillator configured as described above,
The electrode is a conductor on the back side of the discharge generating side so as to generate a discharge
And a conductor, wherein the conductor is an optical axis of the laser beam.
Direction, corresponding to the divided conductor
The flow of the laser medium gas between the discharge electrodes is
The feature is that the electric bodies are made to flow counter to each other.
Laser oscillator.