Title :
Terahertz Emission in Asymmetric Quantum Wells by Frequency Mixing of Midinfrared Waves
Author :
Dupont, Emmanuel ; Wasilewski, Zbig R. ; Liu, H.C.
Author_Institution :
Inst. for Microstructural Sci., Nat. Res. Council, Ottawa, Ont.
Abstract :
Generation of terahertz (THz), and sub-THz, coherent waves has been demonstrated at room temperature in GaAs-AlGaAs asymmetric quantum wells by mixing two CO2 laser beams. Two overlapping regimes were studied: the double resonance regime where three states are involved and the optical rectification which relies on two states only. The measured conversion efficiency of ~10-7 W-1 is in reasonable agreement with theoretical predictions. In addition, this technique of THz generation provides a model system to study the emission profile from an ensemble of radiating dipoles. For instance, backward emission and strong diffraction effects have been observed
Keywords :
III-V semiconductors; aluminium compounds; carbon compounds; electromagnetic wave diffraction; gallium arsenide; laser beams; multiwave mixing; resonant states; semiconductor quantum wells; submillimetre wave generation; 293 to 298 K; CO2; CO2 laser beams; GaAs-AlGaAs; GaAs-AlGaAs quantum wells; asymmetric quantum wells; backward emission; coherent wave generation; diffraction effects; double resonance regime; emission profile; frequency mixing; midinfrared waves; radiating dipoles; room temperature; subterahertz wave generation; terahertz emission; terahertz wave generation; Diffraction; Frequency; Laser beams; Laser theory; Nonlinear optics; Optical mixing; Quantum well lasers; Resonance; Stimulated emission; Temperature; Difference frequency mixing; diffraction; intersubband transitions; midinfrared; nonlinear optics; terahertz (THz) semiconductor emitter;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2006.882877
