Refining the Karlsruhe invisibility cloakFrom research conducted at the Karlsruhe Institute of Technology (KIT)
Material that allows us to purposefully direct light can be used to make objects invisible. This unusual property can be generated in so-called metamaterials by targeted microstructuring processes – but only for particular wavelengths of light and, until recently, only from a fixed direction of view (2D).
The members of the group led by Professor Martin Wegener of the Center for Functional Nanostructures (CFN) at the KIT are international experts in this field. Last year they managed to create this invisibility cloak effect three-dimensionally at a wavelength range of 1500 to 2600 nanometres, which is no longer visible but plays a role in telecommunications. Now two members of Wegener’s team, Joachim Fischer and Tolga Ergin, have refined the structure of the Karlsruhe invisibility cloak so that it can direct visible red light in the 700 nanometre wavelength range. In order to generate the required minute 3D structures in a polymer-air mixture, the KIT researchers used a process developed at the CFN known as direct laser writing, the resolution of which was improved using an “optical eraser”. Metamaterials endowed with such optical characteristics have the potential to facilitate innovations in optics, solar cell development, chip production and data transmission.
Media about the subject
- Karlsruhe Invisibility Cloak: Disappearing Visibly
- Prof. Dr. Martin Wegener's group at the Institute of Applied Physics
- Photonic Metamaterials
- New optics with artificial atoms
- Three-Dimensional Invisibility Cloak at Optical Wavelengths, Science, April 2010
- Three-dimensional polarization-independent visible-frequency carpet invisibility cloak, Optics Letters, 2011