Electrically-Driven Optical Antennas Demonstrated for the First Time

Antennas are essential components of all our daily lives, used in radios, mobile phones, Wi-Fi networks, Bluetooth devices, RFID tags, baby monitors and garage door openers amongst other commonplace items. They work by converting electrical power into radio waves for transmission and vice versa for reception. Now, for the first time, an international group of scientists has demonstrated that the fundamental concepts of electrically-driven radio antennas can also be applied to optical frequencies.

Reporting their discovery in Nature Photonics, the team believes that in bridging the gap between electronic and optical communication, their work signals the arrival of ultra-high-resolution displays and faster, smaller and more efficient computer chips.

"We needed two key instruments and found both at Andor", says Professor Bert Hecht of the University of Wurzburg. "In selecting the iXon 897 camera we got a very fast and highly sensitive EMCCD capable of acquiring images and spectra of the nano-antennas electroluminescence at high repetition rates of up to 10 Hz. This meant we could associate each current-voltage value with the number of photons emitted. We also needed a spectrometer equipped with both a low-line-number grating and a mirror in the grating torrent in order to cover a wide spectral range per single shot, position the sample precisely, and acquire the Fourier image emission pattern efficiently. We already owned the Shamrock 303i spectrometer and the upgrade proved simple and cost-effective.

"Furthermore, the new iXon camera interfaced easily with our existing LabVIEW software and we really appreciated the step 'n glue function, which allowed us to automatically acquire white-light spectra in very wide ranges. In our case we needed to acquire spectra from 400-11,000 nm", says Hecht.

Commenting on the demonstration, Antoine Varagnat, Product Manager at Andor Technology, an Oxford Instruments company, said: "The manipulation and characterization of optical fields on the nanoscale, and the creation and detection of light in such small volumes, is a significant breakthrough for computing and imaging. Applications range from on-chip electro-optical communication over single-photon sources to near-field optical microscopy, both immensely important to modern society".