We investigate MIR QCDs (λ= 10µm) operating in the strong light-matter coupling regime. By measuring the optical absorption and the photocurrent, we are able to experimentally retrieve an effective (polariton) extraction efficiency. We develop an intuitive, semi-classical formalism based on the coupled modes theory (CMT) which quantitatively reproduces both the optical and electrical device characteristics.

The results highlights the potential of QCDs to study ISB-polaritonic systems, and establish an intuitive picture of the polaritonic extraction. They constitute a step towards a better understanding of the resonant electrical injection of carriers into a polaritonic state for efficient ISB polaritonic emitters.