Polarization-dependent perfect absorbers/reflectors based on a three-dimensional metamaterial

Conventionally a flat, shiny metal surface can be used as a reflector. Here we show that a microstructured metal surface can be switched from a perfect reflector to a perfect absorber by merely changing the polarization of the incident light. The structure consists of arrays of three-dimensional standing U-shaped resonators (SUSRs), which are fabricated by two-photon polymerization followed by blanket coating of the metal. For the incidence with a specific polarization, light can be perfectly reflected. By changing the polarization of incident light for 90 degrees, light neither transmits nor reflects. Since the electromagnetic resonance occurs in between the standing arms of a U-shaped resonator, the heat generated in the absorption process is expected to dissipate more easily. The thermal stability of the SUSR absorber has also been investigated.