ABSTRACT
The plasma or free-carrier state in a semiconductor has received considerable attention in the past, owing to its applications in microwave control components. This chapter presents recent advances in the field of ultrafast optoelectronic switching devices and applications based on optically injected free carriers. It demonstrates lightwave switching in laterally coupled GaAs–AlGaAs microring resonators by free-carrier injection. The chapter also presents the application of an ultrafast photonic technique to study polarization switching dynamics of thin-film ferroelectric (FE) capacitors. It demonstrates the use of jitter-free ultrafast rise-time electrical pulses, generated by a semiconductor photoconductive switch with femtosecond laser illumination, FE Pb (Nb, Zr, Ti) O3 capacitors. The pulse method is used to study the polarization switching process in FE materials. The area of the capacitor and the rise-time of the input electric pulse are two parameters characterizing the measurement circuit. Therefore, simulations are carried out to study their effects on the polarization switching, specifically, on the output response.
