Related papers: Spectrally-Selective Vanadium Dioxide Based Tunabl…
Self-adaptive thermoregulation, the mechanism living organisms use to balance their temperature, holds great promise for decarbonizing cooling and heating processes. The functionality can be effectively emulated by engineering the thermal…
We have analyzed spectral weight changes in the conduction and the valence band across insulator to metal transition (IMT) in the VO2 thin film using X-ray absorption spectroscopy (XAS) and resonant photoemission spectroscopy (PES). Through…
The thermal emission of refractory plasmonic metamaterial - a titanium nitride 1D grating - is studied at high operating temperature (540 {\deg}C). By choosing a refractory material, we fabricate thermal gratings with high brightness that…
Vanadium dioxide is currently considered as one of the most promising metarials for oxide elcteronics. Both planar and sandwich thin-film MOM devices based on VO2 exhibit electrical switching with an S-shaped I-V characteristic, and this…
Strongly correlated insulators, such as Mott or charge-transfer insulators, exhibit a strong temperature dependence in their resistivity. Consequently, self-heating effects can lead to electrothermal instabilities in planar thin film…
Vanadium oxide (VOx) is a material of significant interest due to its metal-insulator transition (MIT) properties as well as its diverse stable antiferromagnetism depending on the valence states of V and O with distinct MIT transitions and…
Thermal effects are well known to influence the electronic and optical properties of materials through several physical mechanisms and are the basis for various optoelectronic devices. The thermo-optic (TO) effect - the refractive index…
Reconfigurable optical systems are the object of continuing, intensive research activities, as they hold great promise for realizing a new generation of compact, miniaturized, and flexible optical devices. However, current reconfigurable…
We designed and demonstrated a multi-spectral programmable perfect absorber that exploits two different phase-change materials. This programmability is possible by resonantly coupling two phase change materials, a Ge2Sb2Te5 layer to…
We report the growth of ultrathin VO$_{2}$ films on rutile TiO$_{2}$ (001) substrates via reactive molecular-beam epitaxy. The films were formed by the cyclical deposition of amorphous vanadium and its subsequent oxidation and…
Vanadium dioxide undergoes a metal-insulator transition (MIT) from an insulating (monoclinic) to a metallic (tetragonal) phase close to room temperature, which makes it a promising functional material for many applications, e.g. as chemical…
Semiconductor emitter can possibly achieve sharp cutoff wavelength due to its intrinsic bandgap absorption and almost zero sub-bandgap emission without doping. A germanium wafer based selective emitter with front-side antireflection and…
Engineered optical absorbers are of substantial interest for applications ranging from stray light reduction to energy conversion. We demonstrate a large-area (centimeter-scale) metamaterial that features near-unity frequency-selective…
Light in the mid-infrared (mid-IR) spans wavelengths from 3-8 $\mu$m and is important to many applications such as gas sensing and thermal imaging. Due to materials challenges, there is currently a lack of mid-IR reconfigurable optical…
The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one of the longest-standing problems in condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether the transition is primarily…
Subwavelength nanoparticles can support electromagnetic resonances with distinct features depending on their size, shape and nature. For example, electric and magnetic Mie resonances occur in dielectric particles, while plasmonic resonances…
Managing the emission and absorption of thermal radiation is crucial for a wide range of technologies, from radiative cooling of buildings and vehicles to thermal regulation of satellites and future lunar and Mars habitats. Despite this…
Ultrafast photoexcitation is an emerging route to selective control of phase transitions. However, it is difficult to determine which modes govern the transformation and how effectively they are targeted by photoexcitation. This is…
A limiting optical diode is an asymmetric nonlinear device that is bidirectionally transparent at low power, but becomes opaque when illuminated by sufficiently intense light incident from a particular direction. We explore the use of a…
We introduce and experimentally demonstrate a new class of electrically driven thermal emitter based on globally aligned carbon nanotube metamaterials patterned as nanoscale ribbons. The metamaterial ribbons exhibit electronic and photonic…