LASER PULSE GENERATOR AND GENERATION METHOD

[PROBLEMS] To provide a stable pulse high repetition laser oscillator employing a laser medium of low amplification gain such as a thin planar shape. [MEANS FOR SOLVING PROBLEMS] A solid laser oscillator comprises at least a pair of laser resonators, a thin planar laser medium to which an active substance having an upper level life longer than the period of repetitive operation as a laser medium is added, a thin planar laser medium provided on at least one reflector in the laser resonator and a Q switch element provided in the resonator, a pumping source for pumping the laser medium optically, and a control section for driving the Q switch element. The control section starts oscillation with the Q switch element in on state and switches the Q switch to off during oscillation that allows the upper level density of active substance in the laser medium to remain, thus interrupting oscillation. Since the upper level pumping density is sustained such that a Q switch pulse can be oscillated when the Q switch is on, stable high repetition pulse oscillation can be achieved.