JP3253008B2 - 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 laser oscillator, and more particularly, to an improvement in a laser tube constituting a laser oscillator.

[0002]

2. Description of the Related Art Conventionally, at least two large- diameter portions which are formed in a cylindrical shape and are provided apart from each other in the axial direction, and a small-diameter portion and a small-diameter portion provided between the two large-diameter portions are provided.
Connect both ends of the small diameter part and the large diameter part adjacent to it.
A laser tube having two successive tapered portions;
This laser tube was provided so as to face each other on the large diameter part.
At least one pair of electrodes and a laser
A laser oscillator including laser gas supply means for circulating and supplying the gas is known. In the above-described conventional laser oscillator, a gas is supplied into the laser tube, and a pair of mirrors are provided outside both ends in the axial direction of the laser tube to excite the laser light.

[0003]

By the way, in the above-mentioned conventional laser oscillator, a specific portion of the laser tube is locally irradiated with the laser beam due to a displacement between the pair of mirrors and the laser tube. May be heated. As described above, when a specific portion of the laser tube is locally heated, a crack is generated in the heated portion, and the airtightness of the laser tube leaks from the cracked portion. And especially, since the laser tube receives a differential pressure between the internal negative pressure and the external atmospheric pressure, if a crack occurs in a specific portion of the laser tube as described above, the crack easily expands,
Airtightness was apt to leak from that part. As a laser oscillator having a double structure of a laser tube, for example, Japanese Patent Application Laid-Open No. S51-134598 has been proposed. However, in the laser tube disclosed in this publication, the inner space of the inner thin tube and the space between the thin tube and the thick tube are not communicated, and the space between the thin tube and the thick tube is substantially large. Atmospheric pressure. Therefore, if a crack occurs in a specific portion of the inner thin tube, there is a disadvantage that airtight leaks from that portion to the space between the thin tube and the thick tube.

[0004]

[Means for Solving the Problems] In view of such circumstances,
The present invention has at least two large-diameter portions formed in a cylindrical shape and separated from each other in the axial direction, and a small-diameter portion provided at a position between the two large-diameter portions, and the small-diameter portion.
Connecting both ends of the part and the large diameter part located adjacent to it
A laser tube having a tapered portion
At least a large diameter section of the tube
Laser gas is circulated through the pair of electrodes and the laser tube.
In a laser oscillator provided with a laser gas supply means for supplying in a loop, a small diameter portion of the laser tube and
The cylindrical covering that surrounds the
Provided from the large diameter portion to the other large diameter portion,
The outer diameter and the outer diameter of the large diameter portion are set to substantially the same size,
Further, the inner peripheral surface of the covering portion, the small diameter portion, and both tapered portions.
A pressure chamber is defined between the outer peripheral surface and the tapered portion.
The above-mentioned pressure chamber and the upper
The small diameter part and the internal space of the tapered part are communicated.
is there.

[0005]

According to the above construction, the pressure chamber has the same pressure as the internal space of the small diameter portion and the tapered portion of the laser tube , so that the small diameter portion has a negative pressure inside the laser tube and the atmosphere outside. No differential pressure acts. Even if a specific portion of the small-diameter portion covered by the covering portion is locally heated and a crack occurs therein, the small-diameter portion is covered with the above-described covering portion while maintaining the airtightness. It is possible to satisfactorily prevent the airtightness from leaking from the place where the airtightness leaks.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a laser oscillator 1 has two laser tubes 2 having the same structure arranged vertically in the axial direction. Are supported by a manifold 3 as a common support member, and the other end of each laser tube 2 is supported by manifolds 4A and 4B as support members. The laser gas supply means 5 includes manifolds 4 at both ends.
The laser gas is supplied into each laser tube 2 via A and 4B, and the laser gas in each laser tube 2 is discharged from the central manifold 3 to the outside, and the laser gas is again supplied from the manifolds 4A and 4B at both ends. It can be circulated and supplied into the laser tube 2. The laser gas supply means 5 includes, on the downstream side of the central manifold 3, a heat exchanger 6 for cooling the laser gas discharged from each of the laser tubes 2, and a blower 7 on the downstream side of the heat exchanger 6. The connection tubes 8 connect the manifold 3 and the heat exchanger 6 and the heat exchanger 6 and the blower 7, respectively. The blower 7 is capable of sending laser gas in two directions. One of the two branched laser gases from the blower 7 is a connecting tube 8A, a heat exchanger 9A for heating the laser gas, and the manifold 4
A is supplied to one laser tube 2 via A, and the other laser gas is supplied to the other laser tube 2 via a connection tube 8B, a heat exchanger 9B for heating the laser gas, and the manifold 4B. . By the way, each of the connection tubes 8, 8A, 8B is manufactured from a non-insulating material, and the shape of each of these connection tubes is cylindrical. Also, one manifold 4
B is provided with a reflection mirror 10 for reflecting the laser light excited in the laser tube 2, and the other manifold 4A reflects the laser light excited in the laser tube 2 and transmits the laser light. An output mirror 11 is provided. The reflection mirror 10 and the output mirror 11 are provided to face each other on the axis of the two laser tubes 2, and the laser light resonated by the pair of mirrors 10 and 11 is directed leftward from the output mirror 11. It can be radiated toward. Each of the laser tubes 2 has a pair of electrodes 1 facing each other.
Two pairs of electrodes 2 and 13 are provided in series, and one of the pair of electrodes is disposed on the end side of each laser tube 2 as the ground electrode 12, that is, on the side of the manifolds 3, 4 </ b> A and 4 </ b> B. Is disposed at the center of each laser tube 2. At this time, the ground electrode 12 may be an anode and the non-ground electrode 13 may be a cathode, or conversely, the ground electrode 12 may be a cathode and the non-ground electrode 13 may be an anode. The pair of electrodes 12 and 13 are connected to a DC high-voltage circuit 15 via an electric wire 14, and a high voltage is applied between the pair of electrodes 12 and 13 in a state where a laser gas is circulated in the laser tube 2. Thereby, a laser gas can be excited by causing a discharge between a pair of electrodes. As shown in FIG. 2 in an enlarged manner, the laser tube 2 is made of cylindrical glass, and large diameter portions 2A having the same diameter are provided at both ends in the axial direction and at the center in the axial direction. At a position between the adjacent large-diameter portions 2A, a small-diameter portion 2B whose diameter is reduced by a predetermined dimension is formed. Both ends of the small-diameter portion 2B are each tapered by a tapered portion 2C.
Is connected to As shown in FIG.
Each of the large-diameter portions 2A has six protruding portions 2D protruding in the radial direction. Then, each protruding portion 2 on the left side end portion
D and the above-mentioned electrode 12
Are attached, and the electrodes 13 are attached to the respective protruding portions 2D of the large-diameter portion 2A at the center of the laser tube 2 facing these electrodes 12. Further, the ends of the electrodes 12 and 13 located inside the laser tube 2 are located at substantially the same position as the inner peripheral surface of the small diameter portion in the radial direction of the laser tube 2 or slightly outside in the radial direction. It is located towards. The configuration described above is not different from the conventionally known configuration. In this embodiment, the small diameter portion 2B of the laser tube 2 is surrounded by the cylindrical covering portion 2E. That is, the left-side large-diameter portion 2A and the central-side large-diameter portion 2A are connected to each other by a cylindrical covering portion 2E having the same diameter and made of the same quality of glass. The portion 2B and the tapered portions 2C located at both ends of the portion 2B are airtightly surrounded. Thus, the first pressure chamber 21 is defined by the inner peripheral surface of the covering portion 2E and the outer peripheral surfaces of the small diameter portion 2B and the tapered portion 2C located inside the coating portion 2E. The first pressure chamber 21 communicates with the internal space of the laser tube 2 by a single through hole 2F formed in the tapered portion 2C on the center side. The large-diameter portion 2A on the right side and the large-diameter portion 2A on the central side are also connected by a cylindrical covering portion 2E of the same diameter and made of the same glass, whereby the small diameter on the right side is formed. The portion B and the tapered portions 2C located at both ends thereof are hermetically sealed. Thus, the second pressure chamber 22 is defined by the inner peripheral surface of the covering portion 2E and the outer peripheral surfaces of the small diameter portion 2B and the tapered portion 2C located inside the coating portion 2E. Then, the second pressure chamber 22
Is a single through hole 2F formed in the right side tapered portion 2C.
Thereby, it communicates with the internal space of the laser tube 2. According to the configuration of the laser tube 2 described above, when the laser beam is excited as described above, the pressure chamber (2
Since the inside of 1,2 ) has the same pressure as the internal space of the laser tube 2 , the differential pressure between the negative pressure inside and the outside atmosphere does not act on the small diameter portion 2B . Even if the small-diameter portion 2B or a specific portion of the tapered portion 2 is locally heated and a crack occurs there, the small-diameter portion 2B is covered with the covering portion 2E.
As a result, the laser tube 2 can be satisfactorily prevented from leaking from the place where the crack has occurred. Further, in the above-described embodiment, the outer diameter of the covering portion 2E and the outer diameter of the large diameter portion 2A are the same. In other words, the laser tube 2 of the present embodiment
Differs from the conventional one in that the outer diameter of the laser tube 2 is the same in the entire area in the axial direction, so that there is no constriction or bent portion on the outer surface of the laser tube 2. Therefore, compared to the conventional case where there was a constriction or bent part on the outer surface,
The strength of the laser tube 2 can be increased.

[0007]

As described above, according to the present invention, it is possible to obtain an effect that the airtightness of the laser tube can be properly prevented from leaking from the place where the crack has occurred.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a laser oscillator showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the laser tube 2 shown in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

[Explanation of symbols]

 2 Laser tube 2A Large diameter part 2B Small diameter part2C taper part 2F Through hole 2E coating portion 12 electrode 13 electrode 21 first pressure chamber 22 second pressure chamber

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 3/03-3/041 H01S 3/097-3/0979 H01S 3 / 104,3 / 134 H01S 3 / 22-3/227

Claims (1)

(57) [Claims] 1. A small-diameter portion which is formed in a cylindrical shape and has at least two large- diameter portions provided apart from each other in the axial direction, and a small-diameter portion provided between the two large-diameter portions.
Connect both ends of the small-diameter part to the large-diameter part adjacent to it.
A laser tube having two tapered portions,
A small number of laser tubes installed facing each other
At least a pair of electrodes and a laser
In a laser oscillator provided with a laser gas supply means for circulating and supplying a gas , the small diameter portion and both tapered portions of the laser tube are kept airtight.
Holding and surrounding the cylindrical coating from one large diameter part to the other
Provided over the large diameter portion, the outer diameter of the coating portion and the large diameter portion
Are set to substantially the same diameter, and
Between the inner peripheral surface and the outer peripheral surfaces of the small diameter portion and both tapered portions.
A pressure chamber is defined and a through hole is formed in the tapered portion.
The pressure chamber, the small diameter portion and the tape
A laser oscillator characterized by communicating with an internal space of a power unit .