Polarization-dependent photocurrent enhancement in metamaterial-coupled quantum dots-in-a-well infrared detectors

We demonstrate polarization-dependent photo-response enhancement in metamaterial-coupled quantum dots-in-a-well infrared detectors. A gold split-ring resonator metamaterial layer was patterned by electron-beam lithography in the detector aperture. In this integrated structure, the detector spectral response is given by the convolution of the metamaterial field enhancement and the original detector response. Our polarization-resolved measurement unambiguously shows that the spectral response can be strongly modified by metamaterial patterning. When the metamaterial resonance matches the QD absorption peak, we obtain a clear enhancement of generated photocurrent. Various metamaterial designs can be employed to implement multi-functional detector structures.