The present disclosure relates a laser arrangement (1) and a method of the laser arrangement, arranged to output energy in the form of laser emission, for emitting controlled Q-switched laser emission. The laser arrangement comprises a gain medium (2) arranged to be excited when pumped, an optical resonator (3), an active Q-switch (4) arranged in the optical resonator, said active Q-switch (4) being controllable between at least a high loss state and a low loss state, and being arranged to introduce loss in the optical resonator to prevent lasing in the high loss state and to affect lasing minimally in the low loss state, a photo detector (5) arranged to detect the presence of a free running pulse (1′) generated by the optical resonator and which occurs when a lasing threshold is reached and a processing circuitry (6) arranged to control (S4) of the state of the active Q-switch based on the detection of the free running pulse.