Terahertz-optical mixing in undoped and doped GaAs quantum wells: From excitonic to electronic intersubband transitions

All-optical wavelength shifting in a semiconductor laser using resonant nonlinearities

“…Indeed considerable investigations have been undertaken of the wavelength shift of near infrared (NIR) beam in the presence of an intense THz beam in a quantum well system. [8][9][10][11] These studies were based on enhanced non-linear susceptibilities where the near-infrared beam was resonant with excitonic interband transitions and the THz beam was resonant with excitonic intersubband levels. The resonances could be modified to engineer the wavelength shift by changing the quantum well geometry 10 or by the application of an external electric field 12,13 and large efficiencies (0.1% -0.2%) could be obtained.…”

Terahertz optical sideband emission in self-assembled quantum dots

“…4 An alternative method for optical switching is terahertz ͑THz͒ electro-optic ͑EO͒ modulation in GaAs quantum wells. [5][6][7][8][9] In this technique, the speed of the switching is not limited by factors such as gain and carrier dynamics as is the case for SOAs and lasers. Furthermore the wavelength can be tuned in such a system via applying electric 5 or magnetic fields.…”

Resonant enhancement of second order sideband generation for intraexcitonic transitions in GaAs/AlGaAs multiple quantum wells

“…Sidebands have been studied in bulk GaAs, 3 but especially in semiconductor heterostructures using magnetoexcitons and excitonic and electronic intersubband transitions. [4][5][6][7][8] Besides high conversion efficiencies, semiconductor heterostructures have the advantage that intersubband energies can be tuned by applying a dc field, 9 making these devices potentially attractive for electrically controlled switches and modulators.…”