8 research outputs found
Reconfigurable multilevel control of hybrid all-dielectric phase-change metasurfaces
This is the final version. Available from Optical Society of America via the DOI in this record. All-dielectric metasurfaces comprising arrays of nanostructured high-refractive-index materials are re-imagining what is achievable in terms of the manipulation of light. However, the functionality of conventional dielectric-based metasurfaces is fixed by design; thus, their optical response is locked in at the fabrication stage. A far wider range of applications could be addressed if dynamic and reconfigurable control were possible. We demonstrate this here via the novel concept of hybrid metasurfaces, in which reconfigurability is achieved by embedding sub-wavelength inclusions of chalcogenide phase-change materials within the body of silicon nanoresonators. By strategic placement of an ultra-thin Ge 2 Sb 2 Te 5
Ge2Sb2Te5
layer and reversible switching of its phase-state, we show individual, multilevel, and dynamic control of metasurface resonances. We showcase our concept via the design, fabrication, and characterization of metadevices capable of dynamically filtering and modulating light in the near infrared (O and C telecom bands), with modulation depths as high as 70% and multilevel tunability. Finally, we show numerically how the same approach can be re-scaled to shorter wavelengths via appropriate material selection, paving the way to additional applications, such as high-efficiency vivid structural color generators in the visible spectrum. We believe that the concept of hybrid all-dielectric/phase-change metasurfaces presented in this work could pave the way for a wide range of design possibilities in terms of multilevel, reconfigurable, and high-efficiency light manipulation.Engineering and Physical Sciences Research Council (EPSRC)Russian Science FoundationRussian Foundation for Basic Researc
Significant influence of metal surface morphology on photon emission from a local tunnel junction at ambient conditions
Self-consistent Modeling of Photoionization-induced Field Distributions in Nanoparticles by Ultrashort Laser
International audienc