In a new concept for an optically regenerativeQswitch which is described, the oscillation of the laser with the cavity closed is sensed by a fast photodiode whose output signal opens the electro‐opticalQswitch. The threshold of the laser as a function of the modulator voltage is theoretically investigated; the empirical results obtained with a YAG:Nd3+laser agree well with theory. The advantages offered by the optically regenerativeQswitch are the easy controllability of the peak power of the giant pulses by way of the modulator voltage and the excellent reproducibility of the giant pulses. The experiments revealed the variations between pulses to be less than 3%. Thus the optically regenerativeQswitch is practical for all giant‐pulse lasers whose emission is required to be highly stable.