Control Method of First Pulse Suppression of Laser

Abstract

The invention relates to a control method for first pulse suppression of a laser. The method is a specially designed Q-switched driving waveform, and the output pulse energy can be controlled through adjusting the high-voltage pulse width. The method can be realized through a technical scheme as follows: a pulse modulation waveform generator, a high-voltage constant voltage source, a high-speed switch module, an electro-optical Q-switched oscillator, a laser power amplifier and a pulse selector. According to the method, the problem of first pulse of the laser is solved, and the first pulse suppression of the oscillator and the amplifier in the laser can be simultaneously solved, so that the pulse laser output by the oscillator and the pulse laser output by the amplifier have the consistent energy finally.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a control method for first pulse suppression of a laser. Background technique [0002] Lasers are more and more widely used in the industrial field, especially in fine processing, such as cutting and drilling of hard and brittle materials such as glass and ceramics, solar cells, PCB, FPC board processing, metal processing, etc. Compared with traditional processing methods, lasers have the advantages of precision, accuracy and speed. [0003] The Q-switched laser has the characteristics of short output pulse width and high pulse energy, and its working method is to realize the output of pulsed laser by changing the loss of the optical field in the laser resonator. The Q switch is controlled by an external specific frequency signal. When the resonator is at a low Q value, the resonator has high loss and no laser output; when the resonator is at a high Q value, the resonator is at a...

AI Technical Summary

Problems solved by technology

During the processing of the first laser pulse, it is easy to cause damage to the workpiece, which is very harmful, resulting in damage or scrap of the product

[0005] For laser amplifiers, there is also the problem of the first pulse. If the amplifier is in a continuous pumping state, the laser gain medium will accumulate a large number of flipped particles. At this time, if the oscillator outputs laser light at a certain frequency, the output after being amplified by the amplifier The laser will also have the first pulse effect, which will also cause damage to the workpiece during processing

[0006] At present, the existing methods of suppressing the first laser pulse are as follows. One is: by installing an optical switch to block the first few amplified giant pulses, and through the asynchronous pulse signal, the amplified pulse is evenly distributed. The disadvantages of this method are: ①It needs to add a set of devices, which increases the complexity; ②: The first pulse exists objectively, which is easy to cause damage to optical devices

The second is: suppress the Q-modulated waveform, such as Figure 4 As shown, this method can realize the first pulse suppression of the oscillator ( Image 6 a), the deep suppression of the amplified first pulse can also be achieved (Figure 6b), but when the pump power of the amplifier is different, due to the different number of flipped particles accumulated, it is impossible to achieve the output energy of the amplified laser pulse under different pump power conditions Uniformity of

This method can only suppress the first pulse of the amplifier, but not the first pulse of the oscillator itself, so it has certain limitations, and due to the addition of a continuous light source and an additional control part, the structure is more complicated

[0007] To sum up, the existing first pulse suppression methods cannot realize the first pulse suppression of the oscillator and the first pulse suppression of the amplifier at the same time, and cannot simultaneously realize the uniformity of the output pulse laser of the oscillator and the output pulse laser of the amplifier.

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