A pulsed time domain waveform tunable fiber laser

Abstract

An embodiment of the present invention provides a fiber laser with adjustable pulse time-domain waveform. The waveform generator is used to generate the target waveform pulse signal, and input the generated target waveform pulse signal into the control circuit; the control circuit is used to output the target waveform pulse signal According to the single pulse energy, it is equally divided into multiple pulse sub-signals, and the multiple pulse sub-signals are respectively transmitted to the corresponding low-gain fiber amplifiers, and each low-gain fiber amplifier is controlled to output sequentially according to the sequence of each pulse sub-signal in the time domain. A sub-pulse laser consistent with the time-domain waveform of the corresponding pulse sub-signal; a power beam combiner is used to splice each sub-pulse laser into a target waveform pulse laser in the time domain. The fiber laser designed in the embodiment of the present invention effectively suppresses the waveform distortion generated during the pulse amplification process, does not need to calculate the pre-compensation signal in advance, is simple to control, can directly realize the output of arbitrary waveform pulse laser, and can meet a wider range of industrial processing needs .

Description

technical field [0001] The invention relates to the technical field of fiber laser, in particular to a fiber laser with adjustable pulse time-domain waveform. Background technique [0002] Fiber lasers have the advantages of high beam quality, convenient thermal management, and strong environmental adaptability, and are widely used in modern industrial processing technology. High-power nanosecond pulsed fiber lasers have great application prospects in metal marking, engraving, and rust removal. In order to further improve the processing range of nanosecond pulsed lasers and meet more processing technology requirements, it is necessary to realize the pulse time-domain waveform adjustable of high-power nanosecond pulsed fiber lasers, that is, to realize the output of pulsed lasers with arbitrary time-domain waveforms. [0003] In order to meet this requirement, the prior art discloses a pulse-shaping MOPA fiber laser based on photoelectric modulation. By modulating the semico...

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Problems solved by technology

[0004] The above scheme realizes pulsed time-domain waveform shaping in the range of hundreds of watts of power, and eliminates the distortion generated in the process of pulse amplification. However, there are many technical bottlenecks in obtaining pulsed lasers with adjustable time-domain waveforms based on the above schemes.

First of all, the above scheme uses an acousto-optic modulator or an electro-optic modulator to pre-compensate the time-domain waveform of the pulsed seed light to eliminate the distortion of the pulse during the amplification process and obtain the pulse of the target waveform. The pre-compensated signal used needs to be based on The time-domain waveform of the target pulse, the gain characteristics of the amplifier, the time-domain characteristics of the pulse seed light and other factors are calculated. Therefore, for each pulsed laser with a specific time-domain waveform, it is necessary to first calculate the time-domain waveform of the pulse precompensation signal, and It is also necessary to correct the precompensation signal according to the laser parameters. This process is extremely cumbersome, so it is difficult to achieve pulsed laser output with arbitrary time-domain waveforms using the above scheme.

Secondly, the acousto-optic modulator and the electro-optic modulator will introduce a large loss, resulting in a decrease in the power of the pulsed seed light after passing through the acousto-optic modulator or electro-optic modulator. To obtain high-power pulsed laser output, it is necessary to add a multi-stage pre-amplifier. This increases the complexity of the system structure

Since the maximum withstand power of the acousto-optic modulator and the electro-optic modulator is about 10W, the signal light time domain waveform finally output by the main amplifier cannot be directly cut, and only the seed light entering the optical amplifier can be compensated

When the output power increases, the gain ratio of the optical amplifier will further increase, resulting in enhanced pulse waveform distortion, and the pre-compensation effect will decrease. Therefore, in this case, only hundreds of watts of average power pulse time-domain waveform shaping can be achieved.

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