JPH0276274A - Metal vapor laser device - Google Patents

Abstract

PURPOSE:To improve laser oscillation efficiency by storing a metal vapor source into a container installed within a discharge tube so that it can move. CONSTITUTION:An anode 4 and a cathode 5 are connected opposingly at both- edge part of a ceramic tube 2 through a connection part 2a and pulse two-pole discharge is made between the electrodes 4 and 5. A metal vapor source 1 is stored within a container 20 and is installed on the inner-side wall of the ceramic tube 2. Thus, it is necessary to place the metal vapor source 1 at approximately 1500 deg.C position to oscillate laser light efficiently. By moving the container 20 where the metal vapor source 1 is installed, it becomes easy to place the metal vapor source 1 at approximately 1500 deg.C position. It improves efficiency of laser oscillation and achieves a large laser output.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a metal vapor laser device, and in particular, uses metal vapor as a laser medium and improves the amount of generated metal vapor to achieve laser oscillation output. , relates to a metal vapor laser device with improved efficiency and the like.

(Prior Art) The structure and operation of a conventional metal vapor laser device will be explained with reference to FIG.

That is, an anode 4 and a cathode 5 are connected to both ends of a ceramic tube 2 in which a metal vapor source 1 is disposed via a joining member 2a, thereby forming a discharge tube. An anode 4 and a cathode 5 in this discharge tube are each provided with an electrode flange 6.

The electrode flange 6 is fixed to a body 9 surrounding the discharge tube, an electrode support flange 7 interposed between the insulating tube 10 and the Brewster tube 11.

Each of the anodes 4 and cathodes 5 is fixed to an electrode support flange 7 via an electrode flange 6.

The outer peripheral surfaces of the ceramic tube 2, anode 4, and cathode 5 are surrounded by a heat insulating material 13, and the outside of the heat insulating material 13 is covered with the body 9 and an insulating tube 10 having an insulating tube flange 19. A pair of Brewster tubes 11 are connected to each electrode support flange 7, and a window 12 is attached to the entrance of each Brewster tube 11, and an output mirror 23 and a total reflection mirror are attached to the outside of these windows 12. A mirror 14 is arranged to form a resonator.

A gas supply pipe 3 that supplies neon (N51) gas, for example, is connected to the Brewster tube 11 shown on the left in FIG. 3, and a gas exhaust pipe 8 is connected to the Brewster tube 11 shown on the right. There is. A high DC voltage is applied between the left electrode support flange 7 and the insulating tube flange 19. In the figure, reference numeral 15 represents a charging capacitor C, 16 represents an intermediate capacitor C2, 17 represents a resistor R118 represents a thyratron, and 22 represents a diode D, respectively.

In the metal vapor laser device having such a configuration, laser oscillation is performed as follows.

First, a discharge buffer gas such as neon gas is supplied from a gas supply tube 3 into a ceramic tube 2 serving as a discharge tube in which a metal vapor source 1 is disposed.Next, anodes are provided at both ends of the ceramic tube 2. A high voltage is applied between the cathode 4 and the cathode 5 to form discharge plasma. The ceramic tube 2 is heated to a high temperature by this discharge plasma, and the metal vapor source 1
From this, vaporized metal particles (metal vapor) that become the laser medium are generated. Furthermore, this metal vapor diffuses into the ceramic tube 2 and is excited by free electrons in the discharge plasma within the ceramic tube 2. Laser light is emitted when this excited metal vapor transitions to a lower energy level.

As mentioned above, the generation of metal vapor that becomes the laser medium is achieved by activating a pulsed high voltage source and discharging it between the picture electrodes 4 and 5.
The energy of this pulsed bipolar discharge is applied to the ceramic tube 2 to heat it. It is heated to 1500℃.

(Problems to be Solved by the Invention) As described above, in the metal vapor laser device, the metal vapor source 1 in the ceramic tube 2 is heated by the heat of the discharge plasma formed in the ceramic tube 2, and a metal vapor suitable for laser oscillation is heated. Generates steam.

In this case, if the amount of metal vapor generated is too large, the discharge energy required for laser beam oscillation will be consumed by the metal vapor.
Oscillation efficiency decreases. Furthermore, if the amount of metal vapor generated is small, the amount of excited metal vapor necessary for laser oscillation will be small, resulting in a decrease in laser oscillation efficiency. At this N, the amount of metal vapor generated increases exponentially with respect to the temperature of the metal vapor WX1, so in order to make the amount of metal vapor an optimal value, it is necessary to control the temperature of the metal vapor source 1 with high precision. .

By the way, the temperature inside the ceramic tube 2 rises due to the discharge plasma, and the heat generated by this is dissipated not only in the radial direction passing through the heat insulating material 13 and being released to the outside, but also through the window at the opening of the Brewster tube 11. 12, etc., and the temperature inside the ceramic tube 2 rapidly decreases toward the window 12. Therefore, the metal vapor source 1 has a chevron-shaped distribution in the axial direction as well. It must be installed in a location with the optimal temperature, but inside the ceramic tube 2! If the metal vapor source 1 cannot be placed in the optimum position, it becomes a cause of inability to perform laser oscillation efficiently.

The present invention has been made in consideration of the above circumstances,
It is an object of the present invention to provide a laser oscillation device in which a metal vapor source can be installed at a position where the temperature is such that a required amount of vapor generation can be obtained.

[Structure of the invention]

(Means for Solving the Problems) In the present invention, in a metal vapor laser device that generates laser light by discharging and heating a discharge tube in which a metal vapor source that generates metal vapor is disposed inside, the metal vapor The source is housed in a container movably installed inside the discharge tube.

(Function) When a buffer gas is introduced into the discharge tube and discharge is started, plasma is generated and the temperature of the discharge tube gradually rises.When the metal vapor source reaches a temperature at which metal vapor can be generated, metal is deposited inside the discharge tube. Steam is evenly distributed. Free electrons in the plasma collide with this metal vapor to excite the metal vapor, creating a state of population inversion inside the discharge tube and generating laser light. Here, the temperature distribution inside the discharge tube is not uniform, but since the metal vapor source is housed in a container that can be moved inside the discharge tube, the metal vapor source is moved to the position where the temperature can be generated most efficiently. By installing the sensor, the laser oscillation can be performed efficiently.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2. Note that in FIGS. 1 and 2, the same reference numerals are used for the same members as those in the apparatus shown in FIG. 3.

In FIG. 1, the metal vapor laser device is provided with a ceramic tube 2 as a discharge tube, and an anode 4 and a cathode 5 are connected to opposite ends of the ceramic tube 2 via connecting portions 2a. . A pulsed bipolar discharge occurs between these electrodes 4 and 5. A heat insulating material 1 is placed on the outer periphery of the ceramic tube 2.
3 is arranged, and a metal body 9 is arranged around its outer periphery.

A metal vapor source 1 is housed in a container 20 and a ceramic tube 2
installed on the inside wall. As shown in an enlarged view in FIG. 2, the container 20 has a wall 21 to prevent the high temperature and molten metal vapor source 1 from flowing out. A suitable material for the container 20 is, for example, a ceramic material.

A Brewster tube 1 is placed on the outside of the electrodes at both ends of the ceramic tube 2.
1 is connected. The Brewster tube 11 on the left side is provided with a gas supply pipe 3 connected to a gas supply system, and the Brewster tube 11 on the right side is provided with a gas exhaust pipe 8 connected to a gas exhaust system. The gas supply pipe 3 supplies a discharge buffer gas such as neon gas into the ceramic tube 2 . Further, the gas exhaust pipe 8 is for discharging buffer gas and the like within the ceramic tube 2 to the outside.

An output mirror 23 and a total reflection mirror 14 are arranged outside the window 12 of the Brewster tube 11, respectively, and the output mirror 23 and the total reflection mirror 14 constitute an optical resonator.

Now, the above-mentioned pulsed bipolar discharge has an anode 4 and a cathode 5.
This is done by a pulsed high-voltage power supply connected to an electrode support flange 7 that supports the electrodes and passes current through them. The pulse high voltage power supply has 15 charging capacitors, 16 intermediate capacitors, and 1 resistor.
7. It is constituted by a well-known circuit consisting of a thyratron 18, a diode 22, etc.

This pulsed high-voltage power supply is designed to generate a discharge current with a rise time of approximately 10 -7 seconds or less by igniting the thyratron 18 with the charge stored in the charging capacitor 15 . The thyratron 18 is a pulse discharge switching element.1 The pulse high voltage it generates has a voltage of several kilovolts to several tens of kilovolts, and a repetition frequency of several kilohertz to several tens of kilovolts.
It is kHz. Symbol A in the figure is the anode terminal, and C
is a cathode terminal, and G is a trigger signal introduction terminal.

Next, the action will be explained.

First, an exhaust system (not shown) is activated to exhaust the inside of the ceramic tube 2, and a buffer gas such as neon gas is supplied via the gas supply tube 3.Next, a pulsed high-voltage power source is activated to exhaust the inside of the ceramic tube 2. Plasma is generated in the metal vapor source 2, and the plasma raises the temperature of the metal vapor source 1 to a temperature at which it can generate metal vapor. The temperature required for laser oscillation is, for example, about 1500° C. when the metal vapor source 1 is copper. By maintaining this state, the metal vapor is uniformly distributed within the ceramic tube 2.

Free electrons in the plasma collide with this metal vapor to excite the metal vapor, and eventually the inside of the ceramic tube 2 enters a state of population inversion. In this state, laser light is generated when the excited metal vapor transitions to a lower energy level. The laser beam generated within the ceramic tube 2 passes through the window 12 and increases in amplitude while being reflected by the output mirror 23 and total reflection mirror 14 that constitute the optical resonator, and eventually reaches the output mirror 23.
The laser light that is extracted after passing through reaches sufficient power.

Here, in order to oscillate laser light efficiently.

It is necessary to place the metal vapor source 1 at a temperature of about 1500°C, and the metal vapor source 1 is installed in a container 20,
Since the container 20 can be moved, it can be easily placed at a position of approximately 1500°C.

In addition, since the molten metal vapor source 1 does not stick to the ceramic tube 2 after cooling, this prevents the ceramic tube 2 from sticking to the ceramic tube 2.
can prevent the risk of damage.

〔Effect of the invention〕

According to the present invention, since the metal vapor source can be moved within the discharge tube, it is possible to install it at a position where the required amount of metal vapor generation can be obtained by utilizing the temperature distribution within the discharge tube, thereby increasing the efficiency of laser oscillation. It is possible to obtain high-output laser output.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention together with a circuit wiring diagram, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a sectional view of a conventional metal vapor laser. FIG. 2 is a cross-sectional view showing the device together with a circuit connection diagram. 1... Metal vapor source 2... Ceramic tube 20
...Container agent Patent attorney Nori Ken Yudo Chika Ken Daishimaru Figure 1 Figure 2

Claims (1)

[Claims] 1. In a metal vapor laser device that generates laser light by discharging heating a discharge tube in which a metal vapor source that generates metal vapor is disposed inside, the metal vapor source is movably installed inside the discharge tube. 1. A metal vapor laser device, characterized in that the metal vapor laser device is housed in a container.