LD end-pumped thermal compensation Q-switched step concentration Tm : YAG laser

In this paper, for the first time, we propose an LD-end-pumped thermal compensation Q-switched step concentration Tm : YAG laser. A novel step concentration Tm : YAG crystal is used as the laser medium to mitigate the severe thermal effects typically encountered in single-doped Thulium crystals. To compensate the thermal lens effect generated by the crystal, we insert a negative lens into the cavity. At a repetition frequency of 100 Hz, an output energy of 7.82 mJ with a pulse width of 152.4 ns is achieved. The center wavelength is 2013.41 nm, and the beam quality is characterize by \(\mathrm{M}_{x}^{2}=1.34\) and \(\mathrm{M}_{y}^{2}=1.39\).