Abstract

Two quantum systems with energy levels in resonance with each other experience a splitting of these levels when the wavefunctions of the systems overlap. In semiconductor structures consisting of pairs of closely spaced quantum wells the wavefunction overlap of charge carriers in the wells leads to a novel kind of intersubband transition. To date, this transition has been studied by interband absorption and luminescence and, most recently, by four-wave-mixing experiments [Leo, 1990]. Here, we report of the first direct absorption measurements of the split-subband transition in coupled quantum wells.

© 1991 Optical Society of America