Method for first-pulse optimization in Q-switched solid-state lasers and Q-switched solid state laser

Abstract

The invention relates to a method for generating a pulse train (2) comprising a plurality of individual pulses (3) having a desired pulse characteristic of the individual pulses (3) by means of a Q-switched solid state laser (1) having a modulator (9) for influencing the pulse characteristic of the individual pulses (3), having the following process steps: generating the individual pulses (3) of a pulse train (2) with a pulse characteristic by applying a temporal initial modulation signal (16a) to the modulator (9); detecting the pulse characteristic of the individual pulses (3) of the generated pulse train (2), generating a modified modulation signal (16) based on the detected and desired pulse characteristic and generating a pulse train (2) having a modified pulse characteristic by applying the modified modulation signal (16) to the modulator (9); repeating the last process step until a predetermined break-off criterion has been fulfilled with regard to an optimal modulation signal (16); and generating a pulse train (2) with the desired pulse characteristic of the individual pulses (3) thereof by applying the optimal modulation signal (16) to the modulator (9). The invention further relates to a Q-switched solid state laser (1) suitable for performing said method.

Description

technical field [0001] The invention relates to a method for generating a pulse train comprising a plurality of individual pulses with a desired pulse characteristic of the individual pulses by means of a Q-switched solid-state laser and a Q-switched solid-state laser suitable for carrying out the method. Background technique [0002] Pulsed Q-switched solid-state lasers are no longer considered in many areas of laser processing of materials. The main component of these processing systems is the actual laser beam source consisting of a resonator, laser active medium and Q-switch. Doped with rare earth ions (ND 3+ , Yb 3+ , Er 3+ ) base crystal (YAG, YVO 4 , YLF) as the laser active medium. These crystals are characterized by laser transitions with fluorescence lifetimes ranging from tens of microseconds to milliseconds. These crystals are thus able to store in a Q-switched laser resonator the energy pumped into the laser medium during the low-Q state. This process is ...

AI Technical Summary

Problems solved by technology

These known methods are unsatisfactory for the following reasons: firstly, the laser operates under conditions of varying pump power, repetition rate and pulse interval ratio in use, so that manual optimization is often required or a very large amount of parameter group and select the appropriate

Second, the first pulse optimization may depend on the application, so that changes in the application require manual optimization of the control parameter set or a larger number of parameter sets must be provided

Third, the optimized parameter set is only applicable to the state at the time of optimization. When the laser Q changes later (optical instrument becomes worse, pump source degrades, HF driver degrades in the case of AOM, etc.), the optimized parameters are not valid in some cases. Refit and manual intervention required

Fourth, a different set of parameters must usually be determined individually for each tool, since optimal parameter values ​​may differ due to component differences and calibration bias between individual tools

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