Ultrafast terahertz detectors based on 3D meta-atoms

In this contribution, we demonstrate ultrafast sub-wavelength (λ/10) THz QWIP detectors based on a 3D split-ring geometry recently developed in our team [3]. The key idea is to exploit a miniaturized loop RF antenna as a coupler element to efficiently feed THz radiation (λ=100-200 μm) into an ultra-sub-wavelength (λ/25) QWIP active core (active volume ~20 μm3), as depicted in Fig. 1(a). The LC resonance of the device has been set by carefully selecting both the capacitor and inductor sizes in order to match the GaAs/AlGaAs QWIP response band (detection peak at ~3 THz) [4].