The First Electric Light Antenna In The World

With electricity bring a Nano antenna to emit light: This is succeeded as the world premiere of physicists at the University of Würzburg. Your only 250 nanometers measuring light antenna imagine in the journal "Nature Photonics".

Tiny electric-powered light sources are sometime in the future - for example, in the displays of smartphones. There is expected to rise rapidly due to the increasing integration of 3D technologies, the pixel density required. Also on computer chips could nano-light sources are used to exchange data loss with the speed of light between different processor cores.

One way to show such light sources Würzburg physicists in a pioneering work in the journal "Nature Photonics", they describe for the first time the production of light with an electrically operated Nano antenna made of gold. Was realized the antenna in the research group of Professor Bert Hecht and the Department of Applied Physics.

Apply laws of antenna technology with light

How can one imagine a light antenna? "It works essentially like their big brothers in the mobile phone," explains Bert Hecht: There are by applying an alternating voltage in the metal electrons excited to oscillate. This means that the antennas emit electromagnetic waves - not somehow, but in a well-defined by the shape of the antenna shape and wavelength.

The laws of antenna technology at the nanoscale to be transferred to light is technically demanding. The Würzburg physicists had to therefore think of something. Successful they were to end up with an ingenious nanostructure: Your light antenna has two arms, which are each provided with a contact wire and their ends almost touch each other.

The tiny space between the arms is prepared with a nanoparticle of gold, touching the arm and the other arm a gap of about one nanometer leaves. The gap is so narrow that electrons can overcome upon application of a voltage it due to the quantum tunneling effect. This vibration with optical frequencies are generated.

Length of the antenna arms intended color of light

The so-constructed antenna radiates electromagnetic waves from the visible light.The color of light is determined by the length of the antenna arms. "We have the most compact electrically powered light source in the world built, whose properties also allow more control by adjusting the antenna geometry," says Hecht would.

In principle, such antennas can therefore build, but to application readiness is still work to be done. On the one hand, physicists have further hone the efficiency: the operation of the light-antenna still too much power is lost as heat. Secondly, the operation stability is to be increased, because so far the golden nano-structure only works for several hours.