Bipolar pulsing circuits for high power high rep rate lasers

Analytical and experimental results are presented on bipolar multistage compression multi-kilohertz, and multi-kilowatt excimer and CO₂ TEA lasers. It is noted that a major drawback of the conventional series Melville compressors are core losses, especially in the final stages, bottlenecking the average power throughput capability. In order to achieve optimal hold-off, the saturable inductor cores have to be reset between successive pulses, requiring two full flux excursions per pulse. A simple modification, introducing pulses with alternative polarity, accomplishes intrinsic resetting and also leads to the requirement of only a single flux excursion per pulse. As magnetic core losses are directly related to the cyclic magnetization frequency, core losses are effectively halved by utilizing bipolar operation. The introduction of nonlinear interstage capacitors into a Melville line will lead to a reduction in hold-off requirement in successive stages because of the resulting noncosinusoidal charging voltage profiles