Terahertz Radiation from Bulk and Quantum Semiconductor Structures

Abstract

An excitation of various semiconductor structures by femtosecond optical pulses leads to radiation of electromagnetic waves in the THz-frequency range. Since the waveform reflects the dynamics of the excited carriers or polarizations from which the THz wave is radiated, the time-domain studies of the emitted THz wave provide a unique way of looking directly into the temporal as well as spatial evolution of the excitation on the subpicosecond time scale. In this Chapter, we present recent studies on the emission of THz waves from nonstationary carrier transport and the coherent oscillation of carrier population in bulk and quantum semiconductor structures. Also discussed in this Chapter are the possibilities of the use of semiconductor structures for the improvement or the development of THz-wave emitters.