JPS5918694Y2 - Coaxial cold cathode gas laser tube - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a coaxial gas laser tube in which the arrangement structure of the thin tube serving as the active region of the laser, the arrangement of the cylindrical cold cathode and anode, and the arrangement structure of their introduction terminals are improved.

As shown in Fig. 1, a conventional gas laser tube, for example, an internal cavity type gas laser tube, has high reflectance for the wavelength of laser oscillation on both sides of a narrow tube 1 that serves as a laser medium tube and generates high-density plasma. A pair of reflecting mirrors 2 and 3 are disposed facing each other, and a cylindrical cold cathode 4 is disposed on the outer periphery of the thin tube 1.
The introduction terminal 5 is embedded in the envelope 6, and the anode introduction terminal 7 is embedded in the bulge formed near the closed end of the thin tube 1, and the protruding inner end portion is used as the anode 7a. When mounted on the case 8, the anode lead wire 9 and the anode lead wire 11 having the stabilizing resistor 10 are attached to the end plate 1 forming the laser output window 12 in the case 8.
The power supply 15 is led out of the case from the end plate 14 on the opposite side of 3.
It is connected to.

In other words, when mounting the laser tube in a cylindrical case, it is necessary to position both the introduction terminals of the electrodes in the laser tube on the opposite side of the laser output window in the case, and the inner diameter of the thin tube 1 is Even if it is large, it is about 1 to 1 mm, so in order to obtain stable laser output against mechanical shocks and vibrations applied to the laser tube, the outer diameter of the thin tube 1 should be 7 to 8 mm or more. It is necessary to increase the thickness of the thin tube 1 to improve its mechanical strength and prevent bending due to the load of the reflector 3 attached to the end of the thin tube 1 and the weight of the thin tube 1 itself. Since it is also a constituent element, it must be made of a material that does not easily permeate the helium gas, neon gas, etc. sealed inside.

However, when a thin tube with an inner diameter of 1 to 2 mm is constructed from a glass tube commonly used for electron tubes, its outer diameter is 4 to 6 mm.
The limit is to form a thin tube with a diameter of 7 to 8 mm or more using a material with low gas permeability.
There are various problems such as requiring advanced technology and being extremely expensive, and also requiring skilled technology to manufacture the thin tube with good straightness without impairing the accuracy of the inner diameter.

In contrast, this invention provides an inexpensive laser tube that can use a standard glass tube, which can be manufactured using normal glass processing methods generally used for electron tubes, for the thin tube that becomes the active region of the laser, and at the same time, The device can be mounted extremely easily in a cylindrical case, and its gist is: a thin tube that becomes the active region of the laser; a cylindrical cold cathode arranged around the outer circumference of the thin tube; An anode corresponding to the cathode and an envelope surrounding and holding the cathode, the envelope having an inner diameter larger than the outer diameter of the capillary and arranged coaxially with the capillary. and a first envelope that holds the thin tube by a support member that constitutes a partition wall, a second envelope that is provided so as to cover the thin tube with a space, and these first and second envelopes. a third envelope having an inner diameter larger than the outer diameter of the envelope and coaxially connected to the first and second envelopes; 2 envelope and 3rd
The anode and anode introduction terminal for inducing discharge are arranged in the first envelope, and the cylindrical cold cathode and its introduction terminal are arranged in the third envelope. The coaxial cold cathode gas laser tube is characterized in that the cathode and anode lead-in terminals are arranged inside a cylindrical space formed by the maximum outer diameter of the laser tube envelope. The gas laser tube is characterized in that the inlet terminal of the cylindrical cold cathode is located near the connection between the first envelope and the third envelope.

This invention will be explained in detail below with reference to the embodiment shown in FIG.

FIG. 2 shows an embodiment of this invention, which includes a thin tube 21 serving as the active region of the laser, a cylindrical cold cathode 22 arranged around the outer periphery of the thin tube 21, its introduction terminal 23, and an anode 24 and its introduction terminal 25. and reflecting mirrors 26 and 27 facing each other at both ends of the thin tube 21 constitute a Reniza tube.

The envelope that surrounds and holds each of these elements is a first envelope 28 that has an anode 24 and its introduction terminal 25.
and a second envelope 31 with a reflecting mirror 27 attached to one end,
A third envelope 29 encloses a cylindrical cold cathode 22 and has an introduction terminal 23 for the cold cathode, and one of the reflecting mirrors 26 and 27 is connected to the first one. The other reflecting mirror 27 is attached to the envelope 28 and the other reflecting mirror 27 is attached to the second envelope 31, so that these reflecting mirrors 26 and 27 are connected to the thin tube 2, respectively.
The laser resonance is made to occur within the thin tube facing the end of the tube.

The first envelope 28 has an inner diameter larger than the outer diameter of the thin tube 21, is arranged coaxially with the thin tube 21, and is integrated with the thin tube 21 by a support member 30 forming a partition wall. The thin tube 21 is connected from the center to the support member 30 and the first envelope 2.
It is surrounded by 8.

The second envelope 31 is provided so as to cover the thin tube at one end, and a reflecting mirror 27 is attached to the other end.

The third envelope 29 has an inner diameter larger than the outer diameters of the first and second envelopes 28. The third envelope 29 is coaxially connected to the first envelope 28 and holds the thin tube 21 via the support member 30 and the third envelope 29 . These first. The third outer enclosure 628, 29 allows the thin tube 21 to have both ends free, and its central portion near the center of gravity is supported by the support member 30.

Therefore, this thin tube 21 is prevented from bending due to its own weight, and at the same time is supported in a structure that does not apply direct external force.

Further, the introduction terminal 23 of the cylindrical cold cathode 22 is located near the connection part with the first envelope 28 in the third envelope 29, and the introduction terminal 23 and the introduction terminal of the anode 24 25 are both housed in a cylindrical space formed by the outer diameter of the third envelope 29.

Therefore, the thin tube 21 does not need to be exposed to the outside of the envelope and constitute a part of the envelope as in the conventional case, and at the same time is supported near the center of gravity, thereby preventing the tube from bending. No direct external force is applied,
Also, the introduction terminal 23 of the cylindrical cold cathode 22 and the anode 24
．． 25 are both led out in the same direction within the cylindrical space formed by the outer diameter of the third envelope 29, the mechanical strength of the thin tube 21 can be made relatively small, and this can be used in general electron tubes. Inner diameter 1-2mm, outer diameter 4
It can be composed of a glass tube of ~6 mm 1, and further a thin tube 21. There is no need to place importance on the gas permeability of the material, and in addition, it is easy to connect the lead wires to the introduction terminals 23, 25 when mounting this Reniza tube on a case.

Note that the partition wall formed by the support member 30 has electrical insulation properties and separates the discharge space between the cylindrical cold cathode and the anode, and these discharge spaces are communicated only through the inside of the thin tube 21. It was designed so that

As mentioned above, the coaxial cold cathode gas laser tube according to this invention has a structure in which all thin tubes are isolated from the outside world by the first envelope, the second envelope, and the third envelope, so the gas Since it is not necessary to use a thin tube made of a glass material with low transmission, and there is no need to attach a reflecting mirror to the tube itself, a relatively thin-walled standard glass tube can be used as the thin tube.

In addition, the thin tube is held in a predetermined position with respect to the first envelope by simply connecting it to one end of the first envelope at the center, which also improves manufacturing accuracy. It is also advantageous from above.

This invention can be applied not only to internal reflector type gas laser tubes but also to external reflector type laser tubes, and can also be applied to laser tubes in which the cathode introduction terminal 3 is placed on the reflector 7 side. It is possible.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of a conventional gas laser tube, and FIG. 2 is a side sectional view of an embodiment of a coaxial cold cathode gas laser tube according to this invention.

Claims (1)

[Scope of utility model registration request] A thin tube that becomes the active region of the laser, a cylindrical cold cathode placed around the outer periphery of the thin tube, a cold cathode placed coaxially with the thin tube, one end of which holds the center of the thin tube, and a reflecting mirror attached to the other end. a second envelope disposed coaxially with the thin tube, having a reflecting mirror facing the reflecting mirror at one end thereof, and having a space at the other end covering a part of the thin tube; A coaxial cold cathode gas laser tube comprising: a third envelope that surrounds the thin tube and the cylindrical cold cathode, the ends of which are sealed to the central portions of each of the envelopes.