Cleverly Folded Nanostructures for Future Wireless Optical Communication

A research team at ­Leibniz IPHT has successfully developed optical hybrid nanostructures that precisely direct and control the light emission of individual quantum emitters. This achievement paves the way for the development of efficient photonic circuit components that can be used, for example, in wireless optical ­communication.

The researchers use DNA origami technology to create functional and nanoscopic structures with defined properties. They fold scaffolds of DNA into a sui­table three-dimensional template to place a single dye molecule and metallic nanoparticles in the desired spatial configuration. These hybrid nanostructures can serve as directional single-photon light sources in photonic nanocircuits that use light for signal processing. The specific design allows to control the direction of propagation of the emitted photons.

In their current work, the researchers present an extremely compact meta-emitter that is less than 150 nanometers in size. It consists of three 60 nanometer large, spherical gold nanoparticles that are held together by a triangular DNA origami. A fluorescent dye molecule is cleverly placed in the center of the gap between two gold nanoparticles. This nanoantenna has the special property of directing the emitted light in a specific direction.

The method enables unidirectional light emission, which is of great interest for applications in quantum communication and wireless optical nanocircuits. Experimental studies have shown that the plasmonic nanoantenna design can increase the emission by a factor of 23 while reducing the size by at least a factor of 5 compared to the previously realized Yagi-Uda nanoantennas. This lays the foundation for increasing the efficiency of wireless optical communications.

The original idea for this work arose during the traditional doctoral seminar in Dornburg in 2017 between the research departments Nanooptics and Nanobiophotonics at Leibniz IPHT. In collaboration with the group of Prof. Guillermo Acuna at the University of Fribourg, Switzerland, the researchers jointly published their results in the journal ACS Nano.

Original publication: https://doi.org/10.1021/acsnano.3c05649