Detecting intersubband polaritons in a single nanoantenna

Electronic transitions between confined states within a quantum well are widely used in optoelectronics. Familiar examples include quantum cascade lasers and quantum well infrared photodetectors, which can operate in a wide range of wavelengths, from the far- to near-infrared. There is growing interest in studying this phenomenon because it may enable novel devices such as polariton lasers and because the physics of ISB polaritons is relatively unexplored. Researchers now demonstrated that it is possible to study polaritons in a single isolated nanoantenna.