Nanosecond Pulse Source Based On Optical Switch

In recent years, high power pulsed technology (HPPT) has been widely used in many fields and caused attention from more and more researchers. The high voltage pulser can be used in the following aspects:military defense, high-tech research and civilian industry. As all the other burgeoning technologies, HPPT has an extensive development prospect and great research value; at the same time, its research faces enormous challenges. In this paper, we investigate the PCSS technology and laser diode (LD) driver technology, and then develop a nanosecond pulser based on2-stage Blumlein coaxial voltage.According to the general principle of transmission lines, the working mechanism of using the Blumlein transmission line to generate high voltage pulse is analyzed, and the impact of parasitic parameters in the circuit on the output pulse waveforms is also investigated by use of the simulation software Pspice. Moreover, the possible methods to reduce and avoid these parasitic parameters are explored as well. At last, a2-stage coaxial Blumlein line is designed. This device enjoys many advantages, like simple configuration, low cost and compact size, and etc.Around the research direction of large current and narrow pulse width, a LD driver is designed to drive LD to transmit pulsed laser. This device comprises two modules, namely pulse shaping and power amplification. The pulse shaping module carries the function of pulse-width modulation and pulse-delay. The PA module is used to amplify the current of pulse passed LD, whose core component is MOSEFT. The key point to decrease the rise time is to enlarge the drive current at MOSFET gate. The current passed LD driving by different methods is compared by experiment.The working stability of using the LD instead of YAG laser to trigger PCSS is analyzed experimentally. The results obtained indicate that the waveform of output pulse and the trigger jitter is the function of laser energy and the bias voltage of PCSS. When the biased electric field of PCSS is lOKV/cm and the excitation power supply of LD is above60V, the voltage jitter magnitude is less than5%and the trigger jitter is below0.6ns, which means the stability of output pulse is satisfactory.