Electronic pulse width controller for flashlamp pumped lasers

Abstract

A flashlamp pumped laser is controlled to emit a series of narrow pulse width laser pulses in quick succession. A control circuit associated with the flashlamp receives firing signals of limited pulse duration and serves to ignite and extinguish the flashlamp in accordance with the leading and trailing edges of a single firing signal pulse. The laser generates a coherent light pulse corresponding to the pumping flashlamp pulse. The flashlamp control circuit includes a main capacitor which stores electric charge sufficient to provide current to the flashlamp for several pulses in succession. The circuit also includes a trigger capacitor which supplies current through a transformer coupled to the flashlamp to initiate current conduction therein. Both circuit paths, the main path through the flashlamp and the auxiliary path from the trigger capacitor, are commonly connected to an Insulated Gate Bipolar Transistor (IGBT) which serves as a switch to turn the flashlamp on and off in response to a firing signal pulse.