1.26 μm intersubband transitions in In0.3Ga0.7As/AlAs quantum wells
Applied Physics Letters
We observed room-temperature intersubband transitions at 1.26 microns in n-doped type-II In_0.3Ga_0.7As/AlAs strained quantum wells. An improved tight-binding model was used to optimize the structure parameters in order to obtain the shortest wavelength intersubband transition ever achieved in a semiconductor system. The corresponding transitions occur between the first confined electronic levels of the well following mid-infrared optical pumping of electrons from the barrier X-valley into the well ground state.