Near-field study of the strong coupling between intersubband transitions in quantum wells and single patch antenna resonators in the mid-infrared

Exploiting the coupling of laser beams to atomic force microscopy probes, both scattering and absorption of mid-infrared radiation (wavelengths of 5 to
$11\ \mu \mathrm{m}$
) have been measured in the near field region of single patch-antennas, strongly coupled to the intersubband transition of an InGaAs/AlInAs quantum well.