JPS5837706B2 - Gas Laser Kanno Mirror Fuchiyakuhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sealing a gas laser tube mirror, and more particularly to a method for obtaining a gas laser tube whose optical axis is adjusted without causing deformation or destruction to the mirror substrate or deposited film.

Conventionally, a method has been adopted in which a jig capable of adjusting the optical axis of an internal mirror gas laser tube is fixed to the laser tube body using a lamp.

In this case, an organic adhesive was used to bond the mirror and the laser tube body, but recently, complete glass sealing has been considered in order to extend the life of the gas laser tube and improve reliability.

However, in order to seal the mirror with glass, it is necessary to heat and melt it, which poses problems such as distortion of the mirror substrate and destruction of the dielectric deposited film.

For example, mirror substrate and laser? Copal glass was used for the tube body, a laminated film of TiO2 and SiO2 was used for the mirror vapor deposition film, and Toshiba GS-65K51 was used as the solder glass.
8, when welding solder glass heated to 650 to 700°C to a rubber substrate, cracks may occur on the surface of the deposited film.
It takes less than 10 seconds to do so.

However, it is nearly impossible to adjust the optical axis in a short time of about 10 seconds.

Therefore, if an attempt is made to adjust the optical axis with sufficiently high precision, a fatal defect will occur in the mirror.

Therefore, a method has been considered in which the optical axis is not adjusted when the mirror is sealed, and only the sealing is performed by heating for a short time without damaging the mirror, and then the optical axis is adjusted.

For example, there is a method in which a part of the conduit is heated with a burner and deformed by an external force, or a part of the conduit is made of a soft metal such as copper and also deformed by an external force.

However, the former method has disadvantages in that the heat is easily diffused and there is a large risk of destroying the reservoir and its welded parts, and the latter method has a complicated structure and the optical axis is easily misaligned.

This invention was made in view of the above points, and it is possible to completely seal the glass in a short time without damaging the mirror, and also to achieve sufficiently accurate optical axis adjustment. The purpose is to provide a method.

That is, the method of the present invention includes the steps of: wrapping a conductor ring around the outer periphery of the end of the gas laser tube; and welding the gas laser tube and the conductor ring with glass; and making the end surface of the gas laser tube perpendicular to the plasma tube axis. This method is characterized by comprising a step of polishing, and a step of welding the ring to the end face of the gas laser tube using the solder glass attached around the conductor ring by energizing the conductor ring to generate heat.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to sealing a reflection mirror of an internal mirror type glass laser tube will be described below with reference to the drawings.

First, as shown in FIG. 1, a conductor ring 2 is attached to the outer periphery of the glass tube 10, which forms the main body of the gas laser tube, at the end on the reflection mirror side.
wrap around.

This conductor ring 2 is provided with an L/carried terminal (not shown) so that direct current or alternating current can flow therethrough.

Next, the end of the glass tube 1 is immersed, for example, in a molten solder glass bath 3 as shown in FIG. 2, and the glass tube 1 and the conductive ring 2 are welded together using the solder glass 4.

At this time, by keeping the inside of the glass tube 1 airtight during immersion, it is possible to prevent solder glass from adhering to the inner surface of the glass tube 1.

Next, the end surface of the glass tube 1 which has been undipped is polished until the conductive ring 2 is exposed or just before it is exposed, as shown in FIG.

This polishing process also serves as optical axis adjustment, so that the end surface of the glass tube 1 is perpendicular to the axis of the discharge capillary (not shown) formed inside the tube, more precisely than the axis of the glass tube 1. Process it into

In this case, the deviation of the vertical line from the end surface of the polished glass tube 1 from the tube axis of the discharge capillary section is d/2 (d is the tube diameter of the capillary section) at the other end of the capillary, that is, on the output side. It is permissible as long as it is not exceeded.

Further, the parallelism between the reflection mirror and the output mirror of the glass tube 10 is also a problem, but this is permissible as long as it is within a degree necessary for laser oscillation, for example, within about 1 mrad in the case of a He--Ne laser.

If it is difficult to cut the conductive ring 2 to the point where it is wound by polishing alone, you may add a cutting process to cut off the conductive ring 2 until just before it is exposed, prior to the polishing process. -o Finally, as shown in FIG. 4, a direct current or an alternating current is passed through the conductive ring 22 to generate heat, melting the solder glass 4 attached around the conductive ring 22, and forming the desired dielectric multilayer film 5. The vapor-deposited reflective mirror substrate 6 is welded to the end face of the glass tube 1.

In this case, it is desirable to heat the end of the glass tube 1 and the reflecting mirror in advance to near the transition point in an electric furnace or the like, and weld them together in as short a time as possible.

In addition, in order to prevent cracks from forming in the mirror substrate 6 and the dielectric multilayer film 5 on its surface, it is desirable to slowly cool the welded part after welding until it reaches a transition point or lower (such as 0 or higher). According to this sealing method, heating during sealing is extremely short, and since the heating is localized by the conductive ring, it does not distort the mirror substrate or cause cracks in the dielectric film. .

In addition, accurate optical axis adjustment is performed during the polishing process of the laser tube end face prior to mirror welding, and since mirror welding is completed in a short time, the optical axis will not be deviated during the welding process. There is no need to adjust the optical axis again afterwards.

Note that this invention is not limited to the above embodiments.
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For example, in the embodiment, a glass tube was used as the laser tube, but it can also be applied to a laser tube made of other inorganic dielectric materials such as ceramics. Although it is assumed that a current is caused to flow, a so-called induced current may be used.In addition, the present invention may be modified in various ways within the temperature range without departing from the spirit thereof.

[Brief explanation of the drawing]

FIGS. 1 to 4 are sectional views at various steps for explaining an embodiment in which the present invention is applied to sealing a reflection mirror of an internal mirror type gas laser tube. DESCRIPTION OF SYMBOLS 1... Glass tube, 2... Conductor ring, 3... Solder glass melt tank, 4... Solder glass, 5...
Dielectric multilayer film, 6... mirror substrate for reflection.

Claims (1)

[Claims] 1. A step of wrapping a conductive ring around the end of the gas laser tube and welding the gas laser tube and the conductor ring with solder glass, and polishing the end surface of the gas laser tube so that it is perpendicular to the axis of the gas laser tube. A method for sealing a mirror in a gas laser tube, comprising the steps of: energizing the conductor ring to generate heat, and welding the mirror to the end face of the laser tube by means of glass adhered around the conductor ring.