It was shown recently that driving an optically excited quantum well with a terahertz (THz) frequency electric field can lead to higher-harmonic generation in the THz regime: the THz analog of the dynamic Franz–Keldysh effect. We propose a new double-pulse excitation method that not only increases the efficiency of the harmonic generation but is also able to control somewhat the dominant upshifted harmonic of the THz radiation by means of selective excitation of spatially chosen electron–hole relative motion wave packets.
© 1999 Optical Society of America
(190.2640) Nonlinear optics : Stimulated scattering, modulation, etc.
(190.4160) Nonlinear optics : Multiharmonic generation
(270.5530) Quantum optics : Pulse propagation and temporal solitons
(270.5580) Quantum optics : Quantum electrodynamics
(320.7130) Ultrafast optics : Ultrafast processes in condensed matter, including semiconductors
S. Hughes and D. S. Citrin, "Two-pulse nondegenerate excitation of electron-hole wave packets in quantum wells: tunable terahertz emission," Opt. Lett. 24, 560-562 (1999)