A passive Q switching laser device according to an embodiment of the present technology includes: a passive Q switching laser; a signal source; a modulation unit; and a power source unit. The passive Q switching laser includes an excitation light source that emits excitation light, and a resonator that is excited by the excitation light to emit oscillation light. The signal source outputs a drive signal for driving the excitation light source. The modulation unit modulates, on the basis of emission timing at which the oscillation light is emitted from the passive Q switching laser, the drive signal output from the signal source. The power source unit drives, on the basis of the drive signal modulated by the modulation unit, the excitation light source to emit the excitation light.