JPS6311793B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to gas laser tubes.

In general, in a gas laser tube, in order to reduce reflection loss of parallel polarized light components, it is necessary to provide a Brewster window on the optical axis between the resonator reflecting mirrors to linearly polarize light.

In conventional gas laser tubes, this Brew Star window is fixed to the end of a capillary tube that regulates the discharge area placed inside the envelope tube, or to one side of a reflector support tube that is provided protruding from both end plates of the envelope. It is provided. However, when a pre-use window member is provided directly at the end of a capillary tube, it is necessary to cut and polish the end of the capillary tube precisely to match the pre-use angle, which increases the cost. When using a member, there are drawbacks such as the mechanical strength is unstable and the weight causes displacement of the capillary tube, making it impossible to obtain the desired discharge area regulating effect. On the other hand, in a configuration in which a Breustar window is provided in a reflector support tube, which is usually made of metal, the length of the reflector support tube increases, which limits the length of the envelope tube constituting the envelope. As a result, the internal volume of the enclosure becomes smaller, resulting in a shortened service life.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a gas laser tube in which a Brewster window can be provided very simply and accurately without sacrificing the service life.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a hard glass enclosure tube, 2,
Reference numeral 2' denotes a metal end plate which constitutes a seal together with the seal tube 1, and the end plates 2, 2' are joined to close the openings at both ends of the seal tube 1. 3 is a capillary tube extending along the optical axis X arranged in the sealed tube 1; 4 and 4' are the end plates 2, 4 and 4' extending along the optical axis X;
The metal reflector support tubes 5, 5' are provided to protrude outward so as to penetrate through the reflector support tubes 4, 2'.
4', and 6 and 6' indicate reflective films formed on the inner surfaces perpendicular to the optical axis X of the reflector bases 5 and 5', as shown in FIG. At the proximal end of the capillary tube 3 opposite to the free end,
A circular straight connecting tube 7 having a larger diameter than the capillary tube 3 is provided, and the connecting tube 7 is connected to the sealed tube 1 through the skirt portion 8 so that these are integrally constructed. 7 by said capillary tube 3
In addition, a Brewster window 9 is provided in the connecting tube 7 by holding a Brewster window member in a metal holding frame that is held in pressure contact with the connecting tube 7.

The brew star window 9 in the illustrated embodiment is
As shown in FIG. 2, it consists of two retaining plate portions 10A, 10A whose distal edges expand, and a connecting plate portion 10B which connects these retaining plate portions 10A, 10A at their other edges. In the holding frame 10 made of an elastic metal plate, the holding plate portion 10
A, 10A, as will be described later, are configured to face each other when restrained in the direction of approaching each other, and holding slits 10C, into which the Brewster window member 11 is inserted, respectively. 1
0C, and a circular light transmission through hole 10D is formed in the connecting plate portion 10B.

Then, as shown in FIG. 3, with the holding plate portions 10A, 10A of the holding frame 10 being restrained in the direction in which their leading edges approach each other, both side edges are inserted into the holding slits 10C, 10C. By doing so, the Brewster window member 11 is held in this holding frame 10.
The holding frame 10 is fixedly held by holding the holding plate portions 10A, 10A in elastic pressure contact with the inner circumferential surface of the connecting tube 7 by the both side edges of the holding plate portions 10A, 10A.

Note that 12 is a cathode, 13 is a conductive member, and 14 is an exhaust pipe.

Since the gas laser tube of the present invention has the above-described configuration, light generated by gas discharge in the capillary tube 3 passes through the brew star window 9 to the reflective films 6, 6'.
The linearly polarized laser beam is reflected and resonates, and a linearly polarized laser beam is extracted.

Therefore, in the present invention, the brew star window 9
, the connecting tube 7 that holds one end (base end) of the capillary tube 3
Therefore, there is no need to provide an independent member exclusively for holding the Brewster window in the envelope tube, and since the connecting tube 7 is located inside the envelope tube 1, the entire There is no need to increase the length. Since the connecting tube 7 has a circular straight tube shape with a larger diameter than the capillary tube 3, its strength can be made sufficiently large, and it does not have an adverse effect such as displacing the capillary tube, so the oscillation state of the laser beam is maintained. The BrewStar window 9 can be reliably held without affecting the image quality, and since the connecting tube 7 has a circular straight pipe shape, the BrewStar window 9 can be held in the desired position along the optical axis. It is easy to provide accurately on the X.

Specifically, in the illustrated example, since the holding frame 10 is made of a metal plate, the shape and holding of the holding frame 10 in a suppressed state depend on the shape of the inner peripheral surface of the connecting pipe 7. Slit 10C, 1
It is possible to accurately form the shape of 0C,
In this way, the Brewster window member 11 can be accurately placed at a Brewster angle with respect to the optical axis X.

Further, in the present invention, since the brew star window 9 is provided in the connecting tube 7 following the capillary tube 3 in the envelope tube 1, the internal volume of the envelope is not sacrificed, and therefore a long service life is obtained. be able to.

Further, as in the illustrated example, by using the holding frame 10 made of an elastic metal plate, the brew star window 9 can be installed extremely easily. That is, before joining the one end side end plate 2, the holding plate portions 10A, 10A of the holding frame 10 are restrained and held with a gripping tool such as tweezers, and the holding plate portions 10A, 10A are held together.
10A is made to hold the Brewster window member 11, and in this state, it is inserted into the connecting pipe 7 through the skirt portion 8 using a gripping tool, and then the restraining force of the gripping tool is released. part 10
A and 10A come into pressure contact with the inner circumferential surface of the connecting pipe 7 due to their expansion restoring force, and the holding frame 10 is held. The Brewster window member 11 will always be held at the Brewster angle with respect to the optical axis X as long as the connecting tube 7 is in the shape of a straight tube parallel to the optical axis X.

Further, the brew star window member 11 is attached to the holding frame 10.
Because it is inserted and held in the holding slits 10C, 10C, rather than being fixed or fixed integrally with the Brewster window member 11, the suppressed deformation of the holding frame 10 and the influence of thermal deformation after placement are directly affected by the BrewStar window member 11. Therefore, they do not cause distortion or damage to the Brew Star window member.

Further, in the illustrated holding frame 10, a circular light transmission through hole 10D is formed in the connecting plate portion 10B, and the oscillation mode of the laser beam can be controlled by appropriately controlling the diameter d of this through hole 10D. This makes it possible to achieve laser oscillation with high efficiency.

FIG. 4 shows another embodiment of the present invention, in which the holding frame 10 is rotated around the optical axis The holding frame posture control member 15 has a base end fixed to the end plate 2, and a plate-shaped tip thereof is attached to the upper edge of the holding frame 10, as shown in FIG. be confronted. By displaying the position of the holding frame posture control member 15 on the end plate 2 on the outer surface, it is possible to know the polarization direction of the laser beam extracted from the gas laser tube, and thereby the laser beam is used. It is possible to achieve consistency in the equipment that is used. The holding frame attitude control member 15 may be slidably engaged with the holding frame 10 in a direction parallel to the optical axis, for example.

Furthermore, in the above example, the holding frame 10 is held within the connecting tube 7 only by bringing it into elastic contact with the inner circumferential surface of the straight connecting tube 7, but in the present invention, As shown in FIG. 6, a groove 16 is formed on the inner circumferential surface of the connecting pipe 7, and an engaging portion 17 that elastically falls into the groove 16 is formed on the holding frame 10. By engaging the engaging portion 17, it becomes possible to hold the holding frame 10 more firmly.

As detailed above, according to the present invention, it is possible to provide a gas laser tube that has a very simple structure, allows a BrewStar window to be provided very easily and accurately, and has a long service life.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway sectional view for explaining the gas laser tube of the present invention, Fig. 2 is a perspective view for explaining the Brew Star window, Fig. 3 is an explanatory view of the Brew Star window in the installed state, 4 and 5 are explanatory diagrams of a holding frame attitude control member for a brew star window in another embodiment of the present invention, respectively, and FIG. 6 is an explanatory diagram of still another embodiment of the present invention. 1... Enclosed tube, 2, 2'... End plate, 3... Capillary tube, 4,
4'...Reflector support tube, 5,5'...Reflector base, 7...
Connection pipe, 8...Skirt part, 9...Brew star window, 10...Holding frame, 10A...Holding plate part, 10B
...Connecting plate part, 11...Brew star window member, 1
2... Cathode, 15... Holding frame attitude control member.

Claims (1)

[Scope of Claims] 1. An enclosure composed of a glass enclosure tube and end plates provided to close openings at both ends thereof, and a resonator provided on each of the end plates so as to face each other along the optical axis. a reflecting mirror; and a glass capillary tube disposed within the envelope tube along the optical axis, the capillary tube comprising:
A circular straight connecting tube having a diameter larger than that of the capillary tube is connected at one end thereof and is integrally connected and held to the opening edge of one end of the sealed tube, and a metal holding frame is held in pressure contact within the connecting tube, A gas laser tube characterized in that a BrewStar window member is held in this holding frame. 2. The gas laser tube according to claim 1, further comprising a holding frame attitude control member that controls the attitude of the holding frame within the connecting pipe.