Combined Laser Self-Induced and Pulsed High Voltage Plasma Shutter to Generate Multiple Purpose Ultra Short Laser Pulses.

Short and low-energy laser pulses are achieved through techniques like mode locking, free induction decay, and pulse slicing with electro-optic devices, but often require further amplification due to their low energy content. A laser pulse shutter employing laser self-induced plasma techniques for laser pulse shaping is presented. This device is capable of generating laser pulses whose durations range from the microsecond to tens of nanoseconds, particularly in the case of CO2-TEA lasers. The generated short laser pulses find utility in various applications such as material processing and remote sensing. However, these shutters are unpredictable due to operational jitter. In this work, gas breakdown occurs through two channels: an electrical channel delivering a high voltage pulse slightly below the gas breakdown threshold to initiate plasma, and an optical channel activated by a focused laser pulse surpassing the gas breakdown threshold within the shutter. The rapid rise time of the high voltage pulse acts as a plasma gas pre-ionizer, enhancing energy stability and pulse profile repeatability. Pre-ionizing the sealed shutter gas with a high voltage (HV) pulse prior to the laser pulse arrival ensures exceptional energy stability and pulse width repeatability in the clipped pulse. Once the plasma forms, it truncates the remaining laser pulse, ensuring repetitive short pulses with high temporal and energy stability. The plasma shutter, mounted on an optical rail, integrates a 4-stage magnetic pulse compression (MPC) circuit as part of the pulse forming network. This approach capitalizes on an all Solid-State Exciter (ASSE), utilizing solid-state switches that combine high-power semiconductor and magnetic switches, offering cost-effectiveness, reliability, and high repetition rates without lifetime limitations or warm-up times, unlike thyratrons.