Event Dates
From: 13/03/2024 12:00
To: 13/03/2024 14:00
External Speaker
Prof. Kuniaki Konishi (Institute for Photon Science and Technology, The University of Tokyo, Japan)
FORTH Seminar Room: C. Fotakis

Structures smaller than the wavelength of light or electromagnetic waves, appropriately designed to control optical response, are called meta-optics or metamaterials and have recently attracted attention as a way to realize ultra-thin and functional optical components. Our research group is working in two directions to extend the possibilities of these electromagnetic meta-structures. Until now, lithographic techniques have been mainly used to fabricate nanoscale or microscale artificial structures smaller than the wavelength of electromagnetic waves. However, this has been problematic because it requires a clean-room environment and expensive equipment. We have recently succeeded in fabricating moth-eye anti-reflective structures and meta-lenses using state-of-the-art ultrashort pulsed laser processing with performance comparable to ones fabricated by lithography. This has the potential to simplify meta-structure fabrication methods dramatically. The second is meta-optics that operate in the vacuum ultraviolet region, where the wavelength is shorter than 200 nm. Although there are still very few meta-optics in this wavelength region, we have found that it is possible to convert the wavelength of the visible laser to vacuum ultraviolet light and control its polarization by fabricating meta-structures on freestanding dielectric thin films (nanomembranes). This can potentially become a new platform for creating vacuum ultraviolet photonics. In this seminar, I will introduce these recent research topics in our group.