JPH0480550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal ion laser that eliminates the generation of a magnetic field that adversely affects discharge and improves the stability of laser output.

[Conventional technology]

In this type of metal ion laser, which generally uses metal vapor as the laser medium, the vapor is obtained by vaporizing metal ion generating materials such as cadmium (Cd), selenium (Se), tellurium (Te) by heating or electric discharge. ing. In this case, the heating method is to house the metal ion generating material in a reservoir provided in the laser tube, and heat this reservoir with a heater. In addition, in order to stably maintain the discharge state necessary for laser operation, the laser tube and electrode section are heated with a heater and maintained at a constant temperature.

[Problem that the invention seeks to solve]

However, in conventional metal lasers that use heaters to heat the laser tube, electrode section, and reservoir of metal ion generating material, the magnetic field generated by the heater wire has a negative effect on the discharge, making it impossible to obtain stable laser output. There was a problem.

[Means for solving problems]

The metal ion laser according to the present invention was made to solve the above-mentioned problems, and the heating means for heating the laser tube, the heating means for heating the electrode part, and the heating means for heating the metal ion generating material are non-inductive. Each consists of a heater.

[Effect]

In the present invention, since the heating means is constituted by a non-induction heater, no magnetic field is generated that has an adverse effect on discharge, thereby improving the stability of laser output.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a longitudinal sectional view of a laser tube showing an embodiment of the metal ion laser according to the present invention, FIG. 2 is a partially cutaway perspective view of the same laser, and FIG.
FIG. In these figures, 1 is
Laser tube filled with He gas, 2 and 3 are Brewster windows, 4 is a hollow cathode, 5a, 5b, 5c
is the main anode, 6a, 6b are the auxiliary anodes, 7 is the cathode, 8
a, 8b, 8c are reservoirs containing metal ion generating material 9 such as Cd metal; 10 are main anodes 5a, 5b, 5;
c and a heating means for heating the auxiliary anodes 6a and 6b; 11 is a heating means for heating the reservoirs 8a, 8b and 8c and evaporating the metal ion generating material 9; 12 is a heating means for heating the metal ion generating material 9;
He gas supply source, 13 a getter for removing impurities in the laser tube 1, 14 a positive column discharge path, 15 a glow region, 16 a cathode dark region, 17
18 is a base, 19 is an adjustment screw, 20 is a cover, 21 is an exhaust fan, 22 is a slit hole, and 23 is a heating means for heating the laser tube 1 itself. Note that the heating means 23 is omitted in FIG. 1, and the heating means 10 and 11 are omitted in FIG.

The hollow cathode 4 is formed of a thick conductive pipe made of stainless steel, for example, and its central hole constitutes the cathode bore 30 in which the glow region 15 is generated, and both ends of the hollow cathode 4 are made of ceramic or the like. Cylindrical insulators 31 and 32 are fitted respectively, and a through hole is formed in the peripheral surface corresponding to each main anode 5a, 5b and 5c, and a ring-shaped insulator made of ceramics or the like is also formed in this through hole. Insulator 33
a, 33b, and 33c are fitted and fixed, respectively. Such insulators 31, 32, 33a, 33
b, 33c, cathode material ejected from the surface of the hollow cathode 4 due to sputtering by He ions adheres to and solidifies on the main anodes 5a, 5b, 5c;
With this cathode material, the hollow cathode 4 and the main anode 5a,
It is said to be effective in preventing short circuits between the anodes 5b and 5c or the auxiliary anodes 6a and 6b.

The main anodes 5a, 5b, 5c are made of tungsten,
It is made of molybdenum or the like, and is attached via a sealing glass 38 to a cylindrical attachment portion 36 provided integrally with the laser tube 1, as shown in FIG. Further, the insertion end of each main anode 5a, 5b, 5c is formed into a substantially conical or truncated conical shape in order to enhance the discharge effect and prevent burnout due to discharge. And adjacent main anodes 5a, 5
The spacing between b and 5c is relatively small, e.g. active length
In the case of 30cm and bore diameter D0.4cm, it is set to about 2cm.

Each of the reservoirs 8a, 8b, 8c is connected to the laser tube 1.
The hollow cathode 4 has an axial slit 39 formed in the hollow cathode 4 to communicate with the positive column discharge passage 14, respectively. In addition, each reservoir 8a, 8
b, 8c are provided approximately equal to the spacing pitch of the main anodes 5a, 5b, 5c, and shifted by a half pitch.

The auxiliary anodes 6a and 6b pass metal vapor through the bore 30.
It protects the blowback brew star windows 2 and 3 from metal vapor, and the main anodes 5a, 5b, 5
Similarly to c, it is attached to the laser tube 1 via the sealing glass 41 and is provided adjacent to the sides of the insulators 31 and 32. Similarly, the cathode 7 is also attached to the laser tube 1 via the sealing glass 42,
This cathode 7 and hollow cathode 4 are electrically connected.

Heating means 10, 11, 23 characterizing the present invention
is constituted by a non-induction heater 48.
The non-induction heater 48 can be easily manufactured by winding two coils side by side as shown in Figure 5. When current is applied, the directions of current in adjacent wires are opposite to each other, so the inductance (L) cancels out. therefore, it does not generate a magnetic field. in this case,
The heating means 10 includes each electrode 5a, 5b, 5c, 6a,
It is formed by embedding a non-induction heater 48 spirally wound around the portion 6b in ceramics 49. In addition, the heating means 11 also includes the respective reservoirs 8a, 8b,
It is formed by embedding a non-induction heater 48 spirally wound around 8c in ceramics 50. The heating means 23 is a non-induction heater 48.
is formed by directly winding it spirally around the outer periphery of the laser tube 1.

In the metal ion laser having such a configuration, the main anodes 5a, 5b, 5c and the auxiliary anode 6
When a required voltage is applied between the main anodes 5a, 6b and the hollow cathode 4, a negative glow discharge is generated between the main anodes 5a, 5b, 5c and the hollow cathode 4. Here, to explain the case of a He-Cd laser using Cd as the metal ion generating material 9, the heating means 11
Cd vapor is generated by the heating of the reservoir sections 8a, 8b, and 8c and the heat loss of the negative glow discharge, which is sent into the discharge section and transferred to a higher energy level by excited particles such as He ions. Then, this Cd vapor flows toward the hollow cathode 4 due to the electrophoretic effect of the positive column discharge, and an appropriate amount of Cd vapor is present in the plasma of the discharge.
Continuous oscillation can be obtained.

In this case, non-induction heaters are used as the heating means 10, 11, 23 as described above to prevent generation of magnetic fields, so the main anodes 5a, 5b,
The discharge generated between the hollow cathode 5c and the hollow cathode 4 is stable, and therefore stable laser light output can be obtained.

FIG. 6 is a sectional view of a main part showing another embodiment of the present invention. In this embodiment, the heating means 11 for heating the reservoir 8 is connected to an aluminum foil 60 bonded to the surface of the reservoir 8.
, a heat insulating material 61 covering the aluminum foil 60, and a non-induction heater 48 interposed between the aluminum foil 60 and the heat insulating material 61. In such a configuration, heat is transmitted to the reservoir 8 via the aluminum foil 60, so that the reservoir 8 can be heated uniformly.

[Effects of the Invention] As explained above, in the metal ion laser according to the present invention, since the heating means for heating the laser tube and the heating means for heating the electrode portion are each configured with a non-induction heater, no magnetic field is generated. Therefore, the influence of the magnetic field is eliminated, and a stable discharge state can be obtained. Furthermore, if the discharge is stable, stable laser oscillation can be obtained, improving performance.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a laser tube showing an embodiment of the metal ion laser according to the present invention, FIG. 2 is a partially cutaway perspective view of the same laser, and FIG.
4 is an enlarged sectional view of the main part of the laser tube, FIG. 5 is a perspective view of a non-induction heater, and FIG. 6 is a sectional view showing another embodiment of the heating means. 1... Laser tube, 2, 3... Brewster window, 4... Hollow cathode, 5a, 5b, 5c... Main anode, 6a, 6b... Auxiliary anode, 7... Cathode,
8, 8a, 8b, 8c... Reservoir, 9... Metal ion generating material, 10, 11, 23... Heating means, 4
8...Non-induction heater.

Claims (1)

[Claims] 1. A metal ion laser comprising a heating means for heating a laser tube, a heating means for heating an electrode part, a heating means for heating and vaporizing a metal ion generating material, and a non-induction heater.