JPS6062184A - Nitrogen laser device - Google Patents

Abstract

PURPOSE:To produce a stable laser device with long life assured eliminating any reaction of nitrogen gas to electrode discharging surface by a method wherein, in an nitrogen laser device utilizing main discharging electrodes, the main discharging electrodes are made of Ti or Ti alloy material. CONSTITUTION:Main discharge electrodes 11 and 12 confronting to each other are provided in an outer case 7 and a high impedance element 5 is connected to the ends of these electrodes 11 and 12 in parallel while one end of them is likewise connected to a DC high voltage power supply outside the outer case 7 through the intermediary of another high impedance element 6. On the other hand, the outer surfaces of the electrodes 11 and 12 are connected to both grounded capacitors 2 and 3 and the capacitor 2 is further connected to a starting trigger electrode 9 outside the outer case 7 through the intermediary of a starting discharge tube 4. In such a constitution, the main discharge electrodes 11 and 12 are respectively fixed to the capacitors 2 and 3 comprising metallic films provided on both sides of a ceramic substrate. At this time, the main discharge electrodes 11 and 12 may be made of Ti or Ti alloy to avoid any reaction due to glow discharge of nitrogen gas preventing any damage on discharge surface from happening.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a robust, long-life nitrogen laser device.

Nitrogen lasers have the advantage of being able to generate powerful laser light using inexpensive atmospheric pressure nitrogen gas, and generally use a so-called Blumlein circuit. The strongest oscillation line of the nitrogen laser is 3371A (337, lnm), but the rise time of the discharge needs to be several nanoseconds or less, and the Blumlein circuit is suitable for this.

FIG. 1 shows a schematic configuration of this circuit.

In FIG. 1, 11 and 12 are main discharge electrodes, which are placed in parallel with a certain interval, and are connected to two and three capacitors, respectively. 5 and 6 are high impedance elements, and a high resistor or a wire ring of tens to hundreds of microhenries is used, and a voltage of tens of thousands of ports is applied from an external DC high voltage power supply 8 to the cannula electric appliance 2 through the high impedance elements. and 3.

A discharge v4 is connected in parallel to the capacitor 2, and the laser device excluding an external power source is housed in a non-metallic outer box 7, which is filled with nitrogen gas at an appropriate pressure.

Now, when both discharge electrodes are being charged with DC high voltage, when a trigger voltage for starting discharge is applied to the discharge tube 4 from the external trigger power supply 9, the voltage of the capacitor 2 is discharged in a very short time and the charge is becomes zero. At this time, a shock wave is generated between the two discharge electrodes and propagates toward the open end (the side opposite to the DC voltage application point). Therefore, a discharge occurs between the main discharge electrodes, a nitrogen gas laser beam is generated, and an ultraviolet laser beam is emitted to the outside from the open end along the main discharge electrode interval. This is the operating principle of a nitrogen laser device using a Blumlein circuit.

As mentioned above, this nitrogen laser needs to be excited by a pulse with a sharp rise time of several nanoseconds or less, and for this purpose, the series inductance and resistance of the main discharge electrode, capacitor, discharge tube, and return circuit must be minimized. must be reduced. For this purpose, the capacitor 2.3 is arranged such that the electrodes of the capacitor 2.3 are arranged on one side of the insulating plate 10, and the ground electrode 11 is arranged on the back side, as shown in the plan view of FIG. 2 and the side view of FIG. The main discharge electrodes 11 and 12 are brought into contact with the capacitor plates, respectively, and the starting discharge tube 4 is also connected to the center of the capacitor plate.

The capacitance of the capacitor is preferably as large as possible in order to increase the charging energy, but it is necessary to apply high voltage and the rise of the excitation pulse should be as short as possible, so the capacitance is several hundred to several thousand. Picofarad is used,
It is necessary to adhere it closely to the insulating substrate using a method such as vacuum evaporation.

As shown in FIGS. 2 and 3, the main discharge electrodes 11 and 12 are fixed facing each other on the capacitor electrode, and one of them is provided with an adjusting mechanism to adjust the distance between the discharge electrodes. Further, at the start of discharge, a thin metal plate 12 is inserted under the main discharge electrode in order to cause a weak glow discharge. At the start of discharge, the thin metal plates 12 are spaced slightly apart from each other in order to generate a corona discharge between the metal thin plates and then transition to a glow discharge between the main discharge electrodes. There is. Furthermore, the corners of the discharge portion of the main discharge electrode are rounded to prevent the occurrence of arc discharge.

What has been explained above is the conventional nitrogen laser device that uses the Blumlein circuit, but the biggest drawback is:
Stable operation, dielectric breakdown, and long life.

In other words, since a glass/epoxy substrate is used as an insulating substrate, the dielectric constant is low at 3.5 to 5, and the corona properties are poor and easily burnt out.Also, since it contains glass fiber, it is insulating. I am also dissatisfied with the durability.

Regarding this point, a temporary solution was found by adopting a ceramic substrate as the insulating substrate.

Aluminum or tungsten materials have been used as the main discharge electrode in conventional Blumlein nitrogen laser devices. In these cases, even if arc discharge was not generated, the electrode discharge surface was damaged by the glow discharge of nitrogen gas, resulting in a short life.

Therefore, the present invention uses titanium or a titanium alloy material as the main discharge electrode, which reacts with nitrogen gas to form a thin film of titanium nitride on the surface, which prevents further reactions and dramatically improves the lifespan. It was possible to completely suppress the decrease in life due to reactions and showed stable operation over a long period of time.

Similar main electrode erosion occurs when discharging in nitrogen gas to generate a nitrogen laser even without using a Blumlein circuit, so it is very effective to use titanium or a titanium alloy as the main discharge electrode. It is.

The present invention provides a very long-life and stable nitrogen laser device due to the above-mentioned functions and effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a Blumlein type nitrogen laser device, FIG. 2 is a plan view of a Blumlein circuit, and FIG. 3 is a side view of the same. 1□ and 12 are main discharge electrodes, 2 and 3 are capacitors, 4
is a discharge tube for starting, 5 and 6 are high impedance elements,
7 is an outer box, 8 is a DC high voltage power supply, 9 is a starting trigger power supply, 10 is an insulating substrate, 11 is a capacitor grounding electrode, and 12 is a discharge starting electrode.

Claims (1)

[Claims] (1) A nitrogen laser device using a main discharge electrode, characterized in that titanium or a titanium alloy material is used as the main discharge electrode.