Near-perfect 'black'

摘要

Researchers working with metamaterials say that they are near to achieving a surface that can absorb every photon that hits it. Physicist Willie Padilla's group at Boston College in Massachusetts and the team's colleagues at Duke University in Durham, North Carolina, have created structures that provide a proof of principle of these perfectly absorbing surfaces, although they have yet to stop all photons from escaping'. The researchers predict that the material will have initial applications in ultra-sensitive imaging technologies that use terahertz radiation, with wavelengths intermediate between infrared and microwaves. Terahertz imaging is a hotly tipped technology for use in medicine-fully absorbing materials at these wavelengths could help to reveal even the dimmest of features.