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V delu obravnavamo generacijo kratkih laserskih pulzov s tehniko preklopa ojačenja v trdninskem laserju. Ti se uporabljajo na področju obdelovalnih tehnologij in tudi v medicini, pri njihovi generaciji pa sta zahtevana stabilnost in ponovljivost ob poljubnih časih vklopa. Teoretično je opisan prehodni pojav ob vklopu laserja, ki je osnova za tehniko preklopa ojačenja. V nadaljevanju je naveden teoretični model za napoved dolžine laserskih pulzov. Eksperimentalni del zajema analizo dveh konfiguracij laserskega sistema. V prvi gre za sevanje svetlobe z valovno dolžino 1064 nm, v drugem pa svetlobe z valovno dolžino 532 nm, ki je bila generirana s frekvenčnim podvajanjem. Z meritvami relaksacijskih oscilacij in laserskih pulzov preverjamo in potrjujemo teoretični model za dolžino pulzov in preizkušamo zmogljivosti generacije kratkih pulzov. Pri eksperimentih smo dosegli dolžine pulzov najmanj 15 ns in vršne moči do 125 W za 1064 nm svetlobo in dolžine najmanj 33 ns in vršne moči do 73 W za 532 nm svetlobo, pri vršnih močeh 22 W črpalne svetlobe. Izmerili smo zadovoljivo stabilnost za frekvence proženja med 1 kHz in 100 kHz, kar nakazuje na potencialno uporabo laserskega sistema v aplikacijah, v katerih so pulzi proženi ob poljubnih časih. In this paper, we discuss the generation of short laser pulses with the gain-switching technique in a solid-state laser. These are used in the field of processing technologies as well as in medicine, and their generation requires stability and repeatability at arbitrary times. The transient phenomenon when the laser is switched on is the basis for the gain-switching technique and is described in the beginning. Further in this paper a theoretical model for predicting laser pulse duration is presented. The experimental part includes the analysis of two laser system configurations. The first configuration is optimized for the emission of light with a wavelength of 1064 nm, and the second one for the light with a wavelength of 532 nm, which was generated by second-harmonic generation. By measuring relaxation oscillations and gain-switched laser pulses, we verify and confirm the theoretical model for pulse duration and test the ability of short pulse generation. In the experiments we achieved pulse lengths of 15 ns and peak power up to 125 W for 1064 nm light and lengths of 33 ns and peak power up to 73 W for 532 nm light at pumping peak powers of 22 W. A pulse energy stability under 3,2 % was measured for trigger frequencies between 1 kHz and 100 kHz, suggesting the potential use of a laser system in applications in which pulses are triggered at arbitrary times. |
