JPH06101602B2 - Laser oscillator - Google Patents

Description

The present invention relates to a laser oscillator, and more particularly to a laser oscillator capable of easily shaping a laser pulse waveform into a desired waveform.

In order to shape the laser pulse output from the laser oscillator into a desired pulse waveform, conventionally, the laser oscillator is not directly controlled, but pulse shaping is performed outside the laser oscillator. That is, for example, a plurality of semi-transparent mirrors are used to split a laser beam into multiple beams, appropriate phase differences and attenuations are given to each, and then the semi-transparent mirrors are used again to combine the laser beams to obtain a desired beam. Shaped into a pulse waveform. In such a pulse shaping method, there is a problem that the configuration of the apparatus becomes complicated and it is not easy to change to various pulse waveforms.

Further, since it is difficult to electrically control the waveform of the laser pulse in the gas laser, the conventional technique has only changed the frequency or pulse width of the laser pulse or a combination thereof. It was

Therefore, for example, when a laser pulse is shaped into a waveform with a small pulse width and a large peak power value to perform a perforating process in order to obtain a waveform suitable for perforating metal, for example, when welding is performed, pores in the melting region are formed. Occurs more frequently, and the welding condition deteriorates. Therefore, in this case, it is necessary to reduce the peak power value to some extent, and it is also necessary to adjust the pulse width according to the plate thickness of the workpiece. That is, in order to perform other laser processing such as cutting, quenching, and annealing in addition to the above-mentioned drilling, welding, the pulse waveform of the laser pulse needs to be shaped into a waveform suitable for other laser processing, If the pulse waveform is not shaped, improvement in other laser processing accuracy cannot be expected. That is, conventionally, it is difficult to further improve the accuracy of laser processing because the shaping of the laser pulse is not easy.

A first object of the present invention is to provide a laser oscillator that can easily shape the waveform of a laser pulse output from the laser oscillator into an arbitrary shape.

In order to achieve the above object, in the present invention, a pulse voltage is applied to a plurality of discharge regions in a gas laser oscillator simultaneously or with appropriate phase differences.

Referring to FIG. 1, the laser oscillator 1 is similar to an ordinary gas laser oscillator, and includes a gas (N ₂ , He,
A laser tube 3 for enclosing a mixed gas of CO ₂ ) is provided.

A rear mirror assembly 5 having a reflection mirror with a reflectance of about 100% is attached to one end of the laser tube 3, and an output mirror assembly 7 having a half mirror with an appropriate reflectance is attached to the other end. Is attached. A plurality of anodes A1, A2, ... A5 are arranged at a plurality of positions of the laser tube 3 and each anode A
1, A2, ... A5 and a plurality of cathodes C1, C2, ... C5 facing each other are arranged, and a plurality of discharges are provided between each anode A1, A2, ... A5 and each cathode C1, C2, ... C5. Areas D1, D2, ... D5 are formed. Each anode
A1, A2, ... A5 are grounded, and each cathode C1, C2, ... C5 is a power source 9
Is connected to an appropriate power supply control device 11 to which is connected.

With the above configuration, laser gas is appropriately supplied to each of the discharge areas D1, D2, ... D5 of the laser tube 3, and each of the discharge areas D1, D2 ,.
The laser beam LB is oscillated by discharging at.

In order to control the timing of discharge in each discharge area D1, D2, ...
A plurality of switching control devices S1, S2, ... S5 individually connected to the cathodes C1, C2, ... C5 in 1, D2, ... D5 are provided.
Each of the switching control devices S1, S2, ..., S5 is composed of, for example, a switching regulator, and the switching operation thereof is performed under the control of the discharge timing control device 13 connected to the power supply control device 11. The discharge timing control device 13 is composed of an appropriate control device capable of arbitrarily setting and controlling the timing of discharging each of the discharge regions D1, D2, .... Therefore, each of the switching control devices S1, S2, ... S5 is switching-operated simultaneously or with an appropriate phase difference under the control of the discharge timing control device 13 to discharge in each of the discharge regions D1, D2 ,. It is what causes it.

More specifically, as shown in FIG. 2, the switching operation of each switching control device S1, S2, ... S5 is performed with an appropriate phase difference, and it is sufficient to cause each cathode C1, C2, ... C5 to discharge. Applying a pulse P of different voltage, each discharge area D
Discharge is sequentially performed at 1, D2, ... D5, and a laser pulse LP having a waveform as shown in FIG. 2 is output. As is already apparent, when the pulse P having the period T is applied to each of the cathodes C1, C2, ... C5, the pulse laser having the period t is output. That is, the frequency of the pulse laser becomes an integral multiple of the frequency of the pulse P, and the frequency is increased. Further, the period t of the laser pulse LP is reduced so that the laser pulses LP partially overlap each other, that is, each cathode C
By appropriately reducing the period T of the pulse P applied to 1, C2, ..., C5, the output of the laser beam can be a continuous wave output.

Further, as is clear from FIG. 3, for example, the pulse width of the pulse P is 0.1 ms, and the phase difference of the pulse P applied to each cathode C2, ..., C5 is 0.05 ms, 0.1 ms, 0.1 with reference to the cathode C1. ms and 0.15 ms or so, or by applying the pulse P to several cathodes at the same time, each discharge region D1, D
A laser pulse LP 'having a large pulse width and a large peak power value can be obtained by superimposing the laser pulses LP oscillated by the discharge in 2, ... D5.
That is, by appropriately controlling the timing of applying the pulse P to each of the cathodes C1, C2, ... C5, and appropriately controlling the overlap of the laser pulses LP, laser pulses of arbitrary waveforms are obtained.
LP 'can be obtained.

As will be understood from the above description of the embodiments, the present invention is, in short, a plurality of pairs of anodes A1, A2, ... And cathodes C1, C2 ,.
A laser oscillator comprising a plurality of discharge regions D1, D2, ... Formed between the discharge regions D1, D2, ..., and a power source 9 for applying a voltage to each of the discharge regions D1, D2 ,. A power supply control device 11 is provided between the discharge regions D1, D2, ...
In the power supply control device 11, a plurality of switching control devices S1, S2, ... for controlling the discharge timing in the above are provided, and the discharge timing for controlling the switching operation of each of the switching control devices S1, S2 ,. The control device 13 is connected to the power supply control device 11.

As is apparent from the above configuration, in the present invention, the power supply control device 11 is provided with the switching control devices S1, S2, ... For controlling the discharge timing of the discharge regions D1, D2 ,. Each of the switching control devices S1, S2,
Since the discharge timing control device 13 for controlling the switching operation of ... Is connected to the power supply control device 11,
By controlling the switching operation of each of the switching control devices S1, S2, ... With an appropriate phase difference and sequentially applying the pulse P to each of the discharge regions D1, D2, ..., As shown in FIG. You can get LP.

Further, by applying the pulse P to each discharge area with a slight phase difference and simultaneously applying the pulse P to several discharge areas, as shown in FIG. 3, the pulse width is large and the peak power is high. Large laser pulse L
It is possible to obtain P ′.

That is, according to the present invention, each discharge region D has the above configuration.
The timing of the pulses applied to 1, D2, ... Can be controlled appropriately, and the pulse width and peak power value of the laser pulse LP can be controlled arbitrarily.

[Brief description of drawings]

FIG. 1 is a schematic view showing one embodiment of a laser tube for carrying out the method of the present invention. FIG. 2 is an explanatory diagram showing frequency modulation of a pulse laser. FIG. 3 is an explanatory diagram of laser pulse waveform shaping. A1 to A5 …… Anode, C1 to C5 …… Cathode D1 to D5 …… Discharge area

Front Page Continuation (72) Inventor Hidenori Osada United States, California, California Hacienda Heishyutsu Clear River Rain 1919 (56) References Japanese Patent Publication No. 3-37755 (JP, B2) Actual Publication No. 57-52929 (JP, Y2) Special Table 58-500503 (JP, A)

Claims (1)

[Claims] 1. A plurality of pairs of anodes (A1, A2, ...) And cathodes (C1, C2,
...), a laser oscillator comprising a plurality of discharge regions (D1, D2, ...) formed between the discharge regions (D1, D2,
...) is provided by connecting a power supply control device (11) between the power supply (9) for applying a voltage to each of the anodes or the cathodes, and the discharge timing in the discharge region (D1, D2, ...). Multiple switching control devices (S1, S2,
...) is provided in the power supply control device (11), and a discharge timing control device (13) for controlling the switching operation of each of the switching control devices (S1, S2, ...) is provided in the power supply control device (11). A laser oscillator characterized by being connected.