Metamaterial-enhanced quantum infrared detectors (Conference Presentation)

One of the most fascinating properties of metallic metamaterial resonators is their ability to concentrate large electric fields into sub-wavelength regions of space. This property was already highlighted in the seminal paper of J. Pendry, where the concept of metamaterials was first introduced [1]. We recently showed that this property, together with antenna effects can be very beneficial for infrared quantum detectors [2], such as quantum well infrared detectors (QWIPs) and quantum cascade detectors (QCD). For such devices thermally activated dark current imposes cryogenic cooling, which limits their applications. The combination of the absorbing region with metallic metamaterial allows a substantial increase of the light absorption area with respect to the electrical area of the device. As a consequence, the thermal dark current is reduced and the high temperature detectivity is strongly enhanced. I will present our recent implementation of this concept with QWIP detectors operating at \lambda~9µm, that were processed in a metamaterial of double-metal patch antenna arrays . In this case, we not only achieve room temperature operation, but also benefit from the intrinsic high speed of QWIP detectors to obtain heterodyne receivers in the GHz band [3]. In a second part, I will discuss THz metamaterial resonators that were specially designed for intersubband detectors [4], and that would allow further improvements of the detector performance. Reference: [1] J. B. Pendry et al. IEEE Trans. Microw. Theory Techn. 47, 2075 (1999). [2] D. Palaferri et al. New J. Phys. 18, 113016 (2016). [3] D. Palaferri et al. Nature 556, 85 (2018). [4] A. Mottaghizadeh et al. Opt. Express 25, 28718 (2017).