In solid-state Q-switched lasers the achievement of high-power, single-pulse operation becomes more and more difficult as the length and the population inversion of the active material is increased or the temperature lowered. In general, single-pulse operation can be obtained with a standard optical shutter (rotating prism or mirror, Kerr cell, saturable absorber, etc.) by: 1) suitably controlling the time delay of the rotating prism or Kerr cell and the transmission of the saturable absorber, and 2) pumping the active material not too high above threshold. However, the observed output energy is only a small fraction of the energy stored or storable in the active material. Recently, the use of a composite switching device (~,~-), consti tuted by a rotating mirror in connection with a saturable absorber, turned out to be quite efficient in the case of laser reds of large dimensions, in giving single-pulse outputs of increased energy and power with respect to the