Modeling of dynamic effects in a laser-driven semiconductor switch of powerful microwave radiation

We study non-stationary problems of penetration into and reflection from a semiconductor plate of powerful microwave radiation. The plate is a base of the fast switch, which is activated by a laser-driven photoconductivity and is heated by the commutated microwave power. Analytical criteria for stationary solutions are given for activated (quasi-metallic plate) and deactivated (low-loss dielectric plate) states of the switch under the conditions of powerful microwave heating and external cooling. Results of numerical simulations are provided also for problems of the switch activation by a microwave heating initiated by a short-pulsed laser radiation, which rapidly increases the carrier density. Numerical simulations are carried out by means of the FDTD method with the UPML absorbing boundary conditions. Examples show the system behavior depending on the basic parameters of the problem - microwave field intensity, laser pulse energy and semiconductor doping density.