ERA NanoSci - Femtosecond Nano-Optical Magnetic Recording and Retrieval
Theoretical Chemistry: Electronic Structure, Dynamics, Simulation
Final Report Abstract
Optical data storage offers advantages such as non-contact reading and writing of bits at high data rates. The use of ultrashort laser pulses promises a dramatic increase in the writing speed into the region of hundreds of megahertz. However, a problem of optical data storage is ist limited resolution due to diffraction. Optical antennas represent a possible solution to this problem. Optical antennas are metallic nanostructures featuring a resonance of the free electrons at optical frequencies. Optical antennas allow light to be compressed to subwavelength dimensions and simultaneously to enhance the light-matter interaction. To fabricate optical antennas for optical data storage, such nanostructures need to be placed at the tip of a scanning probe. Fort he purpose of optomagnetic writing and reading it is necessary to develop appropriate antenna structures. In this context, we have developed a polarization-maintaining crossed antenna structure. In terms of tip fabrication, we dealt with the transfer of nanostructures between different substrates. Antenna structures were used to write magnetic bits with sub-wavelength dimensions within the project as the main result for the first time. The reading of these bits was achieved using x-ray holography in the framework of international collaborations. For the experiment the antennas were placed directly on the magnetic layer, which may be avoided in future experiments using a scanning probe. During the project it turned out that circular poalrized laser pulses would not be necessarily needed for writing of bits. However, for reading of bits polarization maintaining antennas would still be needed to detect e.g. a faraday rotation.
Publications
- Cross resonant optical antenna. Phys. Rev. Lett. 102, 256801 (2009)
P. Biagioni, J.S. Huang, L. Duo, M. Finazzi & B. Hecht
- Near-field polarization shaping by a near-resonant plasmonic cross antenna. Phys. Rev. B 80, 153409 (2009)
P. Biagioni, M. Savoini, J.-S. Huang, L. Duo, M. Finazzi, & B. Hecht
- Tailoring the interaction between matter and polarized light with plasmonic optical antennas. Proc. of SPIE Vol. 7922, 79220C (2011)
P. Biagioni, X. Wu, M. Savoini, J. Ziegler, J.-S. Huang, L. Duo, M. Finazzi & B. Hecht
- Circular Dichroism Probed by Two-Photon Fluorescence Microscopy in Enantiopure Chiral Polyfluorene Thin Films. J. Am. Chem. Soc.,134 (13), pp 5832-5835 (2012)
M. Savoini, X. Wu, M. Celebrano, J. Ziegler, P. Biagioni, S.C.J. Meskers, L. Duo, B. Hecht & M. Finazzi
(See online at https://doi.org/10.1021/ja209916y)
