1,720,992 research outputs found
Chalcogenide platforms for photonic metamaterials
No full textPhotonic metamaterials - media artificially structured at the nanometre scale - provide extraordinary optical properties not found in nature. In this work I explored opportunities provided by changes of complex optical properties of chalcogenide alloys related to compositional variation and structural phase change to develop switchable and tunable plasmonic and dielectric metamaterials:• I have systematically explored the properties of Bi:Sb:Te across UV to near infrared wavelengths through combinatorial high-throughput mapping techniques for the widest compositional spread reported so far. This study reveals that Bi:Sb:Te has better plasmonic properties than gold at wavelengths below 580 nm and silver below 365 nm; ability to support dielectric (Mie) resonances better than oxides at telecommunication wavelengths beyond 1200 nm; epsilon-near-zero properties across UV to IR wavelengths; sub-unity refractive index (down to 0.7) in the UV and the highest refractive index in the near-IR (up to 11.5 at 1680 nm) reported so far to our knowledge.• I have studied for the first time the plasmonic character of amorphous Bi:Te and developed resonant optical metasurfaces based on this alloy that present strong, period-dependent plasmonic absorption resonances (QMax = 7.5) in the visible range. Furthermore, I have investigated changes of optical properties of this alloy upon structural phase change from amorphous to crystalline phases.• I have studied for the first time channelling of light through nano-hole arrays filled with dispersive low-epsilon chalcogenides. The complex changes in the composite’s spectral response depend strongly on the interplay between the dispersion of the optical properties of the plasmonic nanostructure and the low-epsilon medium and lead to increase of transmission over a broad range of plasmonic frequencies.• I have developed the first switchable UV metamaterials that exploits the low refractive index (equal to 1.07 at 245 nm for c-GST) and phase change properties of chalcogenides. In particular, I have shown that laser-induced structural phase transitions can be used to switch quality factors of dielectric resonances (QMax = 15) in metamaterials without affecting their spectral positions
Tuneable epsilon near-zero in chalcogenides
No full textThe enormous potential of chalcogenides as compositionally-tuneable alternatives to noble metals for plasmonics and ‘epsilon-near-zero’ (ENZ) photonics can be unlocked using high-throughput materials discovery techniques. Taking advantage of the composition-dependent plasmonic properties of binary and ternary telluride alloys, we show the first amorphous ENZ and plasmonic metasurfaces operating across the UV-VIS spectral range
UV resonance switching dataset
No full textDataset for "Reconfigurable Ultraviolet and High-Energy Visible Dielectric Metamaterials" published in Nano Letters.</span
Hollow-core waveguides with n<1 chalcogenide cladding
No full textWe utilize compositionally controlled low refractive index (n<1) chalcogenide semiconductors in hollow-core waveguides operating across ultraviolet frequencies. Such materials enable π-phase shifts over nanometric propagation lengths in slab and fibre configurations
Artificial intelligence for photonics and photonic materials
No full textArtificial intelligence (AI) is the most important new methodology in scientific research since adoption of quantum mechanics and it is providing exciting results in multiple fields of science and technology. In this review we summarize research and discuss future opportunities for AI in the domains of photonics, nanophotonics, plasmonics and photonic materials discovery including metamaterial
Ellipsometrically measured relative permittivity of Sb2Te3
No full textDataset supports:
Piccinotti, D. et al (2018). Optical response of nano-hole arrays filled with chalcogenide low-epsilon media. Advanced Optical Materials. </span
Nano-optomechanical dielectric metasurfaces reconfigurable with light
No full textWe report on the realization of ultrathin free-standing all-dielectric metasurfaces, with sharply resonant optical properties in the near-infrared (telecoms) wavelength range, in which the optical forces generated among constituent elements are sufficient to induce reversible nanoscale structural deformation. With mechanical Eigenfrequencies in the hundreds of megahertz range, the optomechanical response of such structures provides for fast, strongly nonlinear tuning of optical properties at µW/µm2 intensities
Extraordinary properties of chalcogenide metamaterials
No full textFascinating opportunities are offered by metamaterial nanostructures fabricated from materials with highly-dispersive optical properties, between those of ideally plasmonic (e.g. noble metal) and transparent dielectric media. Chalcogenide semiconductors are excellent examples – their optical properties can be engineered by controlling alloy composition and phase state to provide high and low refractive indices, plasmonic, dielectric and epsilon-near-zero characteristics at near-ultraviolet to near-infrared wavelengths. We report here on the application of chalcogenide materials to photonic metasurfaces
GST-on-fibre optical switch - dataset
No full textDataset for:
Martins, T., Gholipour, B., Piccinotti, D., MacDonald, K. F., Peacock, A., Frazão, O., & Zheludev, N. (2019). Fiber-integrated phase-change reconfigurable optical attenuator. APL Photonics, 4, 1-6. [111301]. DOI: 10.1063/1.5116000</span
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