JPS5863188A - Linearly polarizing laser tube - Google Patents

Abstract

PURPOSE:To hold a brewster window in a laser tube without moving in all directions without loss of laser output and polarization with a structure at low cost and mass productivity by employing ?-shaped elastic plate having a slit formed at a brewster angle and a spring-like projection in the brewster window glass plate holding structure of an internal mirror type linearly polarizing gas laser tube. CONSTITUTION:A glass plate 1 inserted into the slit 11 of a plate 10 is urged by a spring-like projection 12 at both ends of a slit, and is simultaneously fixed vertically via spring-like projection 13. Since the plate 10 which holds the plate 1 tends to expand each other at the plate opposed by the reaction of the projection 12, it does not move inside of a cylinder 9, but is fixed at an accurate brewster angle. Since the plate 1 is held at the periphery, the influence of the internal distortion is reduced, thereby decreasing the reduction in the output and the polarization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a holding structure for mounting a glass plate having a Brewster angle in a gas laser tube, particularly an internally mirrored linearly polarized laser tube.

Generally, a gas laser tube is often provided with a burr, a burr having a -star angle, and a -meta window. In particular, in external mirror type laser tubes, a window is attached to the tube end, and the optical resonator mirror is arranged independently on the laser tube, so it is difficult to install the window attached to the tube end so that it has Brewster's angle. It's easy.

However, in an internal mirror type laser tube, since optical resonator mirrors are provided at both tube ends, it is impossible to provide a Brewster window at the tube ends. In a gas laser tube, by providing this Brewster window in the resonator, it becomes possible to determine the polarization direction of the oscillated laser light in one direction. Also, in the He-Ne gas laser, in addition to the 0.6328 μm light, 3.39 μm light is stimulated to emit light.
By providing this burr-metal window, 3.39 μm oscillation can also be suppressed. FIGS. 6 and 7 show examples of conventional configurations in which such an internal mirror type gas laser tube is provided with a burr-metal window. FIG. 6 is an enlarged view of a part of the end of the gas laser tube, and 101 is the laser tube body in which gas is sealed. The end of the laser tube body 1 is inclined to have a Brewster's angle, and a glass plate 102 for a Brewster window is adhesively fixed to the inclined end face. Further, on the opposite side of the glass plate 102 to the side bonded to the laser tube main body 1, a tube 103 whose end face is inclined to have Brewster's angle is bonded to the glass plate 102. At the other end of this tube 103, a mirror 104 is provided perpendicular to the laser axis. In the case of such a structure, the surface to which the glass plate is bonded must be inclined to the Brewster surface, which is difficult and expensive to manufacture, and there may be problems with the airtightness of the joint. FIG. 7 is an enlarged view of one end of the gas laser tube having a metal enclosure dish 105, and a pair of metal inner tubes 106 and 106', one end of which is inscribed in the metal outer tube 105, is inclined at Brewster's angle. It is configured to sandwich the glass plate 102. However, in such a configuration, a slight gap is likely to occur, and the glass plate 102 moves due to the impact, causing the degree of polarization to go awry.The laser output may also decrease, so it is important to avoid contact with the metal outer cylinder 105. Select the inner cylinder 106.106' with a low coefficient of thermal expansion,
A method is adopted in which the glass plate 102 is strongly clamped by thermal stress due to the difference in shrinkage inside and outside by assembling at a high temperature, but this creates internal distortion in the glass plate 102, which has the disadvantage of reducing laser output and polarization degree. . The present invention eliminates these drawbacks, provides a linearly polarized laser tube that is excellent in cost and mass production, and retains the Brewster window within the laser tube so as not to move in any direction without impairing the laser output or degree of polarization. It is something.

That is, a U-shaped elastic plate with a slit cut at the Brewster angle fixes the glass plate from the side and end surfaces by spring-like protrusions, and the cedar plate itself is inserted into the laser tube elastically or by other joining methods. It is characterized by a structure that allows it to be held in place.

The present invention will be described in detail below using examples.

FIG. 1 is a sectional view of a gas laser tube showing one embodiment of the present invention, and FIG. 2 is an exploded view of the left end of FIG. In both figures, reference numeral 1 denotes a glass plate for a Buri-meta window, and a slit 11 formed at a Brewster's angle in the direction of the laser axis is formed on both sides of the U-shaped elastic cedar plate 10 to form a Brewster's angle. It is inserted in the direction shown by . Spring-like protrusions 12 are provided at both ends of the glass plate 1 in parallel with the glass plate 1,
A spring-like protrusion 13 is provided in the center of the slit 11 perpendicularly to the glass plate 1. Further, the opposing plates are connected to each other by a plate having a hole 14 through which the laser beam passes, and such a shaped plate material 10 can be obtained as an inexpensive and integral structure by an easy processing method such as pressing or etching. As the material for the shape plate, a heat-resistant spring metal or the like that does not lose its elasticity even at relatively high temperatures is used. Reference numeral 9 is a cylinder made of glass-metal or the like with an eave, one end of which is connected to the laser tube main body 4, and a U-shaped plate member 10 holding the glass plate 1 is inserted from the open other end. The opposing plate portions of this poem-shaped plate material 10 are made in advance slightly wider than the inner diameter of the cylinder 9, so that they can be fixed inside the cylinder 9 by utilizing the elasticity of the shaped plate material, and in the direction of the laser axis. On the other hand, it is held between the bottom puller 2 of the cylinder 9 and fixed with a solder crow, high-tight adhesive, etc. 3.

5 - 5 is a cathode, 6 is a laser tube, 7 is a cathode introduction rod, and 8 is an anode.

Figure M3.4.5 shows arrows A and B in Figure 2, respectively.
, is a view seen from arrow C. The action of the plate material 10 on which the glass plate 1 is held will be explained using these figures.

As shown in FIG.
The glass plate 1 inserted into the slit has spring-like protrusions 12a, 12b, and 12c provided at both ends of the slit.

12d presses against the side surface of the glass plate from the four directions indicated by the arrows, so it is fixed in the horizontal direction, and at the same time, as shown in Figure 5, a spring-like protrusion is formed in advance to protrude from the slit width. It is also fixed in the vertical direction by taa and 13b. When the shaped plate 10 holding the glass plate 1 is inserted into the cylinder 9 shown in FIG. 3, the opposing plates tend to spread apart due to the reaction force of the spring-like protrusions 12a112b, 12c, and 12d. The four ridgelines of the retainer plate allow it to be fixed at an accurate Brewster's angle without moving inside the cylinder. Moreover, since the glass plate 1 is held in line contact or point contact in the peripheral area, avoiding the center area through which the laser beam 6- passes, the influence of internal distortion of the glass plate is reduced, and the decrease in output and polarization degree is extremely small. .

According to the above method, it is possible to obtain impact resistance that prevents the polarizing pre-metal window from moving in all directions within the laser tube without damaging the laser output or the degree of polarization, and the holding shape plate is pressed. This can be easily done by etching, etc., making it easier to assemble the glass plate into the laser tube, and is also superior in terms of manufacturing costs and mass productivity.

In the above embodiment, the U-shaped elastic plate material is shown in Figures 2 to 5.
The shape is not limited to the shape of the embodiment shown in the figure, and the U-shaped open surface may be deformed in the direction, the plate with slits may have a cylindrical surface or a polygonal cross section, and the number and position of the spring-like projections may be changed. , the elastic deformation direction, etc. are also limited to the above embodiments. Also, the object that holds the shaped board is not limited to a shape that accommodates the entire cedar board, such as a cylinder.

Even if a part of the engraving is fixed to a part of the laser tube by a method such as welding or gluing, the same effect as in the above embodiment can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an internal mirror type linearly polarized gas laser tube showing an embodiment of the present invention, Fig. 2 is an exploded view of the glass plate holder at the left end of Fig. 1, and Fig. 3 is an exploded view of the glass plate holder at the left end of Fig. 2. A view in the direction of the arrow A, FIG. 4 is a view in the direction of the B arrow in FIG. 2, a partial sectional view in the direction of the C arrow in FIG. FIG. 3 is a partial cross-sectional view of the left end of the laser tube. 1...Glass plate, 2...Killer, 3.
...Solder glass, high airtight adhesive, 4...
Laser tube body, 5... cathode, 6... laser thin tube, 7... cathode introduction rod, 8...
Anode, 9...Cylinder, 10...U-shaped elastic plate, 11...S IJ, ), 12.
13... Spring-like protrusion, 14... Hole.

Claims (1)

[Claims] In an internal mirror type linearly polarized laser tube, in which a glass plate in addition to the laser thin tube is arranged at Brewster's angle between a pair of opposing mirrors, the laser axis direction of the opposing plates of U-shaped elastic cedar plates is used. In addition to providing a slit at a vertical angle, the glass plate has a spring-like protrusion at the end of the slit that acts in at least two directions on the side surface of the glass plate, and a spring-like protrusion at the center of the slit that acts perpendicularly to the end surface of the glass plate. . A linearly polarized laser tube, characterized in that a glass plate is pressed and held in the slit.