A5010017476- Transition Metal Oxide Nanomaterials
- Photonic and Optical Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Electron Microscopy Techniques and Applications
- Neural Networks and Reservoir Computing
- Ga2O3 and related materials
- Plasmonic and Surface Plasmon Research
- Advanced Fiber Laser Technologies
- Nonlinear Optical Materials Studies
- Magneto-Optical Properties and Applications
- Advanced X-ray Imaging Techniques
- Electron and X-Ray Spectroscopy Techniques
- Thermal Radiation and Cooling Technologies
- Advanced Fiber Optic Sensors
- Silicon Nanostructures and Photoluminescence
- Optical Network Technologies
- Spectroscopy and Quantum Chemical Studies
- Metamaterials and Metasurfaces Applications
- Mechanical and Optical Resonators
- Geological and Geochemical Analysis
- Quantum Dots Synthesis And Properties
- Phase-change materials and chalcogenides
- Photorefractive and Nonlinear Optics
- Photoacoustic and Ultrasonic Imaging
- Advanced Memory and Neural Computing
PeopleTec (United States)
2022-2025
Vanderbilt University
2013-2023
Vanadium dioxide (VO(2)) is a promising reconfigurable optical material and has long been focus of condensed matter research owing to its distinctive semiconductor-to-metal phase transition (SMT), feature that stimulated recent development thermally photonic, plasmonic, metamaterial structures. Here, we integrate VO(2) onto silicon photonic devices demonstrate all-optical switching reconfiguration ultra-compact broadband Si-VO(2) absorption modulators (L < 1 μm) ring-resonators (R ~ λ(0))....
Phase-change materials (PCMs) have emerged as promising active elements in silicon (Si) photonic systems. In this work, we design, fabricate, and characterize a hybrid Si-PCM optical modulator. By integrating vanadium dioxide (a PCM) within Si waveguide, non-resonant geometry, demonstrate ~ 10 dB broadband modulation with PCM length of 500 nm.
Using light to control transient phases in quantum materials is an emerging route engineer new properties and functionality, with both thermal non-thermal observed out of equilibrium. Transient are expected be heterogeneous, either through photo-generated domain growth or by generating topological defects, this impacts the dynamics system. However, nanoscale heterogeneity has not been directly observed. Here we use time- spectrally resolved coherent X-ray imaging track prototypical induced...
The debate about whether the insulating phases of vanadium dioxide ($\mathrm{V}{\mathrm{O}}_{2}$) can be described by band theory or it requires a strong electron correlations remains unresolved even after decades research. Energy-band calculations using hybrid exchange functionals including self-energy corrections account for metallic nature different but have not yet successfully accounted observed magnetic orderings. Strongly correlated theories had limited quantitative success. Here we...
Abstract Recent years have witnessed significant developments in the study of nonlinear properties various materials at nanoscale. Often, experimental results on harmonic generation are reported without benefit suitable theoretical models that allow assessment conversion efficiencies compared to material’s intrinsic properties. Here, we report observations even and odd harmonics up 7 th, generated from a suspended subwavelength silicon film resonant UV range 210 nm, current limit our...
Ultrafast phase transitions induced by femtosecond light pulses present a new opportunity for manipulating the properties of materials. Understanding how these transient states are different from, or similar to, their thermal counterparts is key to determining materials can exhibit that not found in equilibrium. In this paper, we reexamine case light-induced insulator-metal transition prototypical, strongly correlated material VO$_2$, which nonthermal Mott-Hubbard has been claimed. Here,...
Abstract Hybrid material systems are a promising approach for extending the capabilities of silicon photonics. Given weak electro‐optic and thermo‐optic effects in silicon, there is intense interest integrating an ultrafast‐switching phase‐change with large refractive index contrast into waveguide, such as vanadium dioxide (VO 2 ). It well established that phase transition VO thin films can be triggered by ultrafast, 800 nm laser pulses, pump‐laser fluence critical determinant recovery time...
Further miniaturization of imaging systems is prevented by the prevalent, traditional bulky refractive optics today. Meta-optics have recently generated great interest in visible wavelength as a replacement for thanks to their low weight, small size, and amenability high-throughput semiconductor manufacturing. Here, we extend these meta-optics long-wave infrared (LWIR) regime demonstrate with 2 cm aperture f /1 all-silicon metalens under ambient thermal emission. We showed that even strongly...
Nanoscale phase coexistence and inhomogeneity are ubiquitous in correlated electron materials, existing doped Mott insulators, manganites, high-temperature superconductors. The small length scales lack of contrast mechanisms make it extremely challenging to measure real-space images the with high resolution. Yet, aid our understanding how domain boundaries dictate exotic material properties. Here we show that resonant soft-X-ray holography, previously employed image magnetic domains, can be...
The expansion of optical network traffic demands the implementation all-optical signal processing functions such as switching and modulation within nodes to scale data speeds curb power consumption. Toward this end, we experimentally demonstrate ultracompact modulators based on vanadium dioxide that can be operated by broadband control (800–1000 nm) (1500–1600 wavelengths are simultaneously switched pulse energies low 6.4 pJ. devices integrated on-chip enable planar propagation both light...
Phase coexistence during a solid-to-solid transition in quantum material is measured using x-ray coherent diffractive imaging.
We report experimental observations and numerical simulations of second third harmonic generation from a gold nanograting, which exhibits plasmonic resonance in the near infrared. The is tunable, with spectral position that depends on angle incidence. All things being equal, enhancement nonlinear optical processes produced by field localization nanograting when compared flat mirror manifests itself dramatically ultraviolet to visible range: conversion efficiencies increase more than three...
By uncovering novel aspects of second harmonic generation in aluminum, we show that there are unusual and remarkable consequences resonant absorption, namely an unexpectedly critical role bound electrons play for light–matter interactions across the optical spectrum, suggesting a different basic approach is required to fully explain physics surfaces. We tackle issue never under consideration given generic hostile conditions propagation light absorption. Unlike most noble metals, aluminum...
The enhancement of the nonlinear optical properties hybrid nanoparticle films by coupling between metallic and plasmonic semiconducting nanoparticles is shown. A heterostructure comprising CuS Au separated a thin layer insulating ligands enhanced yield second-harmonic light factor 3.3 compared with sum constituent on their own. Heterostructures were fabricated scalable solution-processing techniques that can create devices arbitrary geometry. In addition to harmonic generation,...
We demonstrate electro-optical modulation in a silicon-vanadium dioxide hybrid device. A combined effect from applied electric field and Joule heating is used to switch microscopic vanadium patch deposited on top of silicon single-mode ridge waveguide.
Using light to control transient phases in quantum materials is an emerging route engineer new properties and functionality, with both thermal non-thermal observed out of equilibrium. Transient are expected be heterogeneous, either through photo-generated domain growth or by generating topological defects, this impacts the dynamics system. However, nanoscale heterogeneity has not been directly observed. Here we use time- spectrally resolved coherent X-ray imaging track prototypical induced...
Nonlinear silicon photonics offers unique abilities to generate, manipulate and detect optical signals in nano-devices, with applications based on field localization large third order nonlinearity. However, at the nanoscale, inefficient nonlinear processes, absorption, lack of realistic models limit nano-engineering silicon. Here we report measurements second harmonic generation from undoped membranes. Using experimental results simulations identify effective mass valence electrons, which...
By uncovering novel aspects of second harmonic generation in aluminum we show that there are unusual and remarkable consequences resonant absorption, namely an unexpectedly critical role bound electrons play for light-matter interactions across the optical spectrum, suggesting a different basic approach is required to fully explain physics surfaces. We tackle issue never under consideration given generic hostile conditions propagation light absorption. Unlike most noble metals, displays...
Recent years have witnessed significant developments in the study of nonlinear properties various optical materials at nanoscale. However, most cases experimental results on harmonic generation from nanostructured are reported without benefit suitable theoretical models and appropriate comparisons to assess enhancement conversion efficiencies compared intrinsic a given material. Here, we report observations even odd harmonics generated suspended subwavelength silicon film, dielectric...
We demonstrate a silicon waveguide modulator with an in-line vanadium dioxide segment as platform for optical switching. A modulation depth greater than 10 dB is achieved device footprint of only 0.28 µm2.
The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one longest-standing problems condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether primarily driven by electronic or structural degree freedom, but measurements date have been stymied their sensitivity only these components and/or limited temporal resolution. Here we use ultra-broadband few-femtosecond pump-probe resolve and transitions VO2 at fundamental time scales. We find...
In the version of this article initially published, y-axis range violin plots in Fig. 4a, now spanning between 0.0 and 1.0, spanned 0.2 1.0.Furthermore, leftmost panel, titled "Coupled Map Lattice (CML)," labels colours for five distributions dynamical regimes coupled map lattices were misplaced, which caused them to appear shuffled not agreement with main text results from 3a.
Nonlinear frequency conversion in metals has been a subject of theoretical and experimental research since the emergence nonlinear optics, partially motivated by their high third order nonlinearities despite its absorption visible near infrared spectral ranges. Enhancement harmonic generation from gold surface demonstrated different nanostructures, especially when excited plasmonic resonances, represents nowadays an active field with applications to functional nano-photonic devices. However,...