Generation of two identical ns laser pulses spaced by a single µs time interval by means of sequential switching of the output mirror transmittance in a diode-pumped Nd:YAG laser is reported, to our knowledge, for the first time. The theoretical study of the process of transmission losses switching is developed. This analysis confirms the possibility of generation of two identical Q-switched laser pulses with 100% efficiency with respect to the referenced single pulse energy. The detailed characterization of the laser in free-running, single and double Q-switching regimes is presented. The laser can be applied in different branches of metrology as PIV, LIBS or holographic interferometry.