Microwave Metamaterial Absorbers with Controllable Luminescence Features

Traditional microwave absorbers can hide target objects from the detection of radar waves without tackling optical waves. However, in actual scenarios, the objects might still be observed by a hyperspectral remote sensor or an imaging system from comparison with environmental optical features, in particular for variable backgrounds. For this aspect, a comprehensive stealthing technique able to deal with microwaves and optical features simultaneously adapting to the variable environment is highly desired. In this work, an ultrathin flexible metamaterial that can simultaneously realize wideband microwave absorption and controllable visible and near-infrared luminescence spectra is proposed. The designed artificial coat can absorb more than 80% of the incident energy in the X-band (8-12 GHz) within a large incidence angle range up to 54° at low polarization sensitivity, while its real-time visible and near-infrared luminescence spectrum can be electrically adjusted through an integrated emission system. The method proposed here can be extended to broader wave bands and find important applications in multifunctional stealthing technologies.