A new material made from several layers of graphene is an effective shield for terahertz and microwave radiation, while letting visible light through. So say researchers in the US, who have created thin films that can be engineered to strongly absorb radiation in a specific band of the electromagnetic spectrum. Shields made of the material could be used to reduce external electromagnetic interference in sensitive electronic equipment and the team also claims that the material could be used to create terahertz filters and polarizers. Such devices could prove useful in the emerging field of terahertz imaging.
http://nanotechweb.org/cws/article/tech/49418