An apparatus for generating short optical pulses is provided having a storage medium capable of storing optical energy, a first module for delivering pumping optical pulses or continuous beam into the storage medium to energize the storage medium, and a second module for delivering one or more trigger optical pulses to the optical storage medium. Each of the trigger optical pulses has a rising edge which causes a cascade release of the energy stored in the storage medium in an output optical pulse having a greater power and narrower in width or duration (at full width at half maximum) than the trigger optical pulse that caused the output pulse. A control module in the apparatus controls the operation of the pump module and trigger module so as to provide the desired characteristics of output optical pulses from the apparatus.