JPS62189779A - Gas laser generator - Google Patents

Abstract

PURPOSE:To obtain an effective pulse-shape laser beam which has a predetermined output and is suitable when bias heat energy is to be avoided by a method wherein a two-step pulse form which is formed by adding a step pulse to a dropping portion of a pulse signal is employed. CONSTITUTION:A base signal circuit 12 predetermines a current DELTAIb arbitrarily and a pulse signal circuit 13 predetermines a current DELTAIp, a frequency DELTAf and a duty DELTAD arbitrarily. As a result, the output of an auxiliary adding circuit 11-b becomes a current pulse of (DELTAIb+DELTAIp). On the other hand, if the dropping point of DELTAIp is detected by a dropping edge detecting circuit 14 and a pulse of a current Ic and a width (t) is obtained by a single pulse generating circuit 15, the pulse form of a main adding circuit 11-a becomes (DELTAIb+Ic+DELTAIp). As a result, the pulse form of the main adding circuit 11-a is given to the grid of a vacuum tube 9. Therefore, the current-I and the voltage-V of a glow discharge 6 become as shown in the figures so that DELTAIb does not overshoot DELTAIB and DELTAIb can be maintained at the minimum value. Therefore, a laser beam which satisfies the predetermined value perfectly can be obtained by the next pulse.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a laser beam control device that can stably output pulsed laser light over a wide range of frequency and duty.

[Conventional technology J In recent years, the scope of laser processing has expanded to non-ferrous metal materials, especially.

It is beginning to be applied to new materials such as ceramics.

That is, since ceramic materials and the like have small thermal expansion and are hard, it is desirable to use a sharp and steep pulsed laser beam when irradiating the material with a laser. However, since the gas laser generator generates a pulsed laser 51 by pulsing claw discharge, a certain amount of bias current t is required to generate the pulsed glow discharge.
-The pulsed laser beam is superimposed on the pulsed signal to improve the ignition of the claw discharge.The bias laser beam is superimposed on the pulsed laser beam to produce the output, which promotes thermal heating during cutting of ceramic materials. However, it has the disadvantage of causing thermal distortion and irregularly shaped cracks.

In addition, Japanese Patent Laid-Open Publication No. 56-42392 can be cited for improving the ignition performance of pulse emission by using this bias current.

[The problem that the invention attempts to solve]

Conventionally, unless a bias current of a certain value 111 or higher is caused to flow continuously, laser light is not output due to the relationship with the internal beam intensity of the optical resonator. The ++i is defined as the minimum glow discharge current. However, when a pulsed claw discharge is performed,
Glow discharge n+: Since the electrical impedance of W changes dynamically, becoming inductance at the time of ignition and capacitance at the time of pulse rest, when the pulsed glow discharge waveform is actually measured, it shows a rise as shown in Figure @3. The upper part vibrates overshoot due to the capacitor impedance load.
The falling portion vibrates overshoot due to the inductance impedance load.

Here, the overshoot oscillation at the rising edge is effective in order to facilitate the ignition of the glow discharge, or the overshoot oscillation at the falling edge is effective in order to facilitate the ignition of the glow discharge. Therefore, C @ ΔIB in Figure 3) makes the next pulse-like rise unstable (i.e.

(The ignition may vary depending on the chance), so it is recommended to increase the bias current and maintain the minimum glow discharge current.

As a result, since the bias current is large, the laser light outputs are continuously superimposed, resulting in pulsed laser light.

An object of the present invention is to provide a control system that can extract only pulsed laser output.

[Means for solving problems]

This problem can be solved by adding a stepped pulse to the falling edge of the pulse signal to create a two-step pulse shape.

[Effect]

At the falling part of the pulse current ΔIp of the pulse signal, ΔIp>
Ic (20, 3ΔIp) (time width is 20.05
By adding m5) and making the pulse into an alternating two-step shape, it is possible to stably obtain pulsed laser light output in a wide range of one frequency Δf duty ΔD.

〔Example〕

Examples of the present invention are shown in Figure 8g1 below. An explanation will be given using an axial flow type gas laser generator.

It consists of a laser head section l, a main power supply section 2, and a control section 3.

A discharge tube with a mirror 7 has a cathode and an anode arranged from one supply tube to the other exhaust tube, and glow emission [6
The mixed gas is brought into a population inversion state and the laser beam 16 is taken out from one mirror.

The glow discharge 6 between both electrodes is connected to the main power supply section 2. The main power supply section 2 is in contact with the cathode 4-1 from the anode 4-2 via the DC power supply 10, the vacuum tube 9, and the stabilizing resistor 8.

The grid of vacuum tubes 9 is connected to the control section 3.

The control section 3 is connected to the main adder circuit 11a, one of the auxiliary adder circuits 11-b, and the base signal circuit 12. The other adder circuit is connected to the single pulse generating circuit 15, and the falling edge detection circuit 14 and the auxiliary adder circuit 11-b are connected to the pulse signal circuit 13 at t1.

These functions I! This will be explained using Figure 2.

The base signal circuit 12 is set to ΔIbt - arbitrarily.

The pulse signal circuit 13 has the same current Δ■p and the same wave number Δf.

Duty ΔD' is set arbitrarily.

As a result, the auxiliary addition circuit 11-b is [ΔIb+ΔIp]
On the other hand, when the falling edge detection circuit 14 detects the q falling point of ΔIp and the single pulse generation circuit 15 obtains a pulse with a current I C+ pulse width t, the main addition circuit 11a The pulse shape is [ΔIb+Ic+
It becomes ΔIpJ. (As a result, the pulse shape 11-a is given to the grid of vacuum tube 9, so
Since the current -I and the voltage -2 of the glow discharge 6 are not caused by the second factor, ΔImt does not overshoot as shown in FIG. 3, and Δlb can be maintained at the minimum value. Therefore, by first-order pulse streaming, it is possible to obtain a laser beam (16 in FIG. 2) that reliably satisfies the set value ΔIp. In the illustration 16 of FIG. 2, t and dIs of the explanation are shown.

Although the laser output of 1wb is shown, since the overshoot vibration as shown in Figure MijJ3 disappears with the IC shown in Figure 2, Δwb can be made zero when ΔIb is the minimum.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a pulsed laser output directly according to the setting, and since there is no bias laser output, there is also no reactive power, which is particularly effective when bias heat energy is disliked, such as in ceramic processing. Pulse-shaped laser light can be obtained.

[Brief explanation of drawings]

A schematic explanatory diagram, 2nd [1, fl] is a pulse waveform diagram of FIG. 1. η1 Figure 2

Claims (1)

[Claims] 1. In a gas laser generator comprising a glow discharge section, a laser gas circulation section, an optical resonance section, and a power supply control section, in order to apply a pulsed glow discharge to the power supply control section,
A gas laser generator characterized by adding a step-like pulse to the pulse trailing edge.