This release is available in German.
More than 120 years after the discovery of the electromagnetic character of radio waves by Heinrich Hertz, wireless data transmission dominates information technology. Higher and higher radio frequencies are applied to transmit more data within shorter periods of time. Some years ago, scientists found that light waves might also be used for radio transmis-sion. So far, however, manufacture of the small antennas has required an enormous expenditure. KIT scientists have now succeeded for the first time in specifically and reproducibly manufacturing smallest optical nanoantennas from gold.
In 1887, Heinrich Hertz discovered the electromagnetic waves at the former Technical College of Karlsruhe, the predecessor of Univer-sitt Karlsruhe (TH). Specific and directed generation of electro-magnetic radiation allows for the transmission of information from a place A to a remote location B. The key component in this transmis-sion is a dipole antenna on the transmission side and on the recep-tion side. Today, this technology is applied in many areas of every-day life, for instance, in mobile radio communication or satellite re-ception of broadcasting programs. Communication between the transmitter and receiver reaches highest efficiency, if the total length of the dipole antennas corresponds to about half of the wavelength of the electromagnetic wave.
Radio transmission by high-frequency electromagnetic light waves in the frequency range of several 100,000 gigahertz (500,000 GHz correspond to yellow light of 600 nm wavelength) requires minute antennas that are not longer than half the wavelength of light, i.e. 350 nm at the maximum (1 nm = 1 millionth of a millimeter). Con-trolled manufacture of such optical transmission antennas on the nanoscale so far has been very challenging worldwide, because such small stru
|Contact: Monika Landgraf|
Helmholtz Association of German Research Centres