Intersubband transitions in InGaNAs/GaAs quantum wells

Abstract
Intersubband transitions are observed in InGaNAs/GaAs quantum wells at wavelengths around 10 μm. The transition energies are correlated with interband transition energies measured in the near infrared. Clear selection rules are observed: the transition is TM polarized. The amplitude of the absorption is consistent with an increase of the electron effective mass as the N content increases.