Enhancing Communication Bandwidths of Organic Color Converters Using Nanopatterned Hyperbolic Metamaterials

The modulation bandwidth of color-converting phosphors used in white light-emitting diodes severely limits the channel capacity of visible light communication (VLC). A variety of color converters replacing the conventional phosphors have been demonstrated and the bandwidth has been enhanced by more than an order of magnitude. However, such enhancement is limited by the intrinsic properties of molecular structures. Here, we propose an alternative strategy of using nanopatterned hyperbolic metamaterials (HMMs) to achieve high-bandwidth color converters. A quantitative model is established to analyze the impact of nanopatterned HMMs on bandwidths and signal-to-noise ratios. Compared with the original bandwidth of 75 MHz of the pristine color converter, we experimentally demonstrate an enhanced bandwidth of 125 MHz using nanopatterned HMMs. To the best of our knowledge, this is the first demonstration of HMM-based color converter for the VLC application. This route provides a solution of breaking through the intrinsic bandwidth limit of color converters.