TERAHERTZ ELECTROMAGNETIC-RADIATION FROM QUANTUM-WELLS

The observation of terahertz electromagnetic dipole radiation from qua ntum well structures has finally proven the existence of charge oscill ations in semiconductors associated with wave packet dynamics. This ar ticle closely examines the physics behind the emission of terahertz el ectromagnetic radiation from excitonic charge oscillations in such qua ntum well structures, points out similarities and differences between the various generation schemes, and discusses the various relaxation m echanisms involved. Finally, we show how both amplitude and phase of c harge oscillations and the corresponding terahertz emission can be man ipulated using phase-locked optical pulses.