Switching between two mid-infrared intersubband absorption energies in double quantum wells

Abstract We present a new efficient modulators structure in which electron tunneling between asymmetric coupled quantum wells is used to populate or deplete the ground level for the infrared absorption, leading to externally controlled infrared absorption at two different wavelengths (here 10.2 μm and 11.4 μm). The temperature dependence of the modulation depth is measured. The experimental results are corroborated by calculations based on a self-consistent model. Monochromatic electron transfer infrared modulators are also presented.