Quantum cascade intersubband polariton light emitters

We propose the use of a quantum cascade approach to achieve photon emission from intersubband cavity polariton states. Judicious quantum engineering of the electronic band structure and of the microcavity resonator allows one to obtain emission in the strong light–matter coupling regime under electrical excitation. In particular, we show that, using InP-based multiple quantum well structures, large polariton splittings of about 40 meV can be obtained within the mid-infrared range of the electromagnetic spectrum (intersubband transition energy ≈130 meV, corresponding to λ ≈ 9–10 µm). The calculations show that the effect is robust with respect to substantial changes of the electronic doping density or of the linewidth of the intersubband transition.