Pulse-off electro-optic Q-switch made of La3Ga5SiO14.

By theoretical calculations we search the hold-on and hold-off state of the pulse-off electro-optic (EO) Q-switch made of La3Ga5SiO14 (langasite, LGS) which exhibits both electro-optic (EO) effect and optical activity (OA), from which the proper applied voltage and orientation of LGS are determined. For the first time to our knowledge, a pulse-off EO Q-switch made of LGS is successfully designed and used in the Nd:YAG laser cavity. Q-switched pulses with energy 360 mJ and pulse width 8.3 ns are obtained, and the dynamic-static ratio is 80%.