Pulse shape generator for laser fusion

Current laser-fusion theory dictates the need for relatively short laser pulses that are shaped in time to implode optimally a fuel pellet. The laser pulse width and shape should be varied to match different types and sizes of targets. For current experiments, pulse widths as short as 100 psec are desirable, which eliminates the choice of relatively slow electrooptic shutters to shape the pulse, since they are limited to rise times and pulse widths longer than several hundred picoseconds. The device described here can generate a wide variety of pulse shapes and widths by stacking a set of 30-psec mode-locked pulses. This versatile pulse stacker currently shapes the pulses for the KMS Fusion neodymium-doped-glass laser system that has produced over 500 neutron-yielding shots since 1 May 1974 by heating and compressing deuterium or deuterium-tritium fuel inside hollow glass spherical targets.