A Coherent Metamaterial Detector

ABSTRACT Metamaterials can be designed to achieve frequency‐selective, near‐unity absorption. One can exploit the absorptance functionality of the metamaterial in order to detect incident radiation. However, a coherent detector, that is both sensitive to phase and amplitude, has yet to be established at high frequencies. In this work, we experimentally demonstrate a frequency, phase, and power‐sensitive metamaterial coherent detector (MCD) operating in the millimeter wave (mmW) range of the electromagnetic spectrum. Our design uses the pyroelectric properties of to enable the detection of mmW radiation. The metamaterial absorbs incident radiation and converts it to heat, thereby generating a pyroelectric signal. Notably, the level of absorption – and thus the detected signal – is coherently controlled by the relative phase and power of the incident fields. This coherent detector approach is scalable to any wavelength range where metamaterial perfect absorbers can be fashioned.