465 citations · 1k across the 21 of their papers we have counts for
22 papers
Temporal Evolution of Blackbody Radiation in a One-Dimensional Photonic Time-Crystal
Luis Cortes-Herrera, Naren Ganesh, Jack Hasty +1
One of the most intriguing phenomena in time varying-media photonics is the amplification of light in a photonic time crystal (PTC). However, studies to date have focused exclusive…
Self-referencing photothermal common-path interferometry to measure absorption of Si3N4 membranes for laser-light sails
Tanuj Kumar, Demeng Feng, Shenwei Yin +12
Laser-light sails are a spacecraft concept wherein lightweight "sails" are propelled by high-intensity lasers. We investigated the near-infrared absorption of free-standing membran…
Lateral beam shifts and depolarization upon oblique reflection from dielectric mirrors
Yuzhe Xiao, Linipun Phuttitarn, Trent Michael Graham +3
Dielectric mirrors comprising thin-film multilayers are widely used in optical experiments because they can achieve substantially higher reflectance compared to metal mirrors. Here…
Wavelength-by-wavelength temperature-independent thermal radiation utilizing an insulator-metal transition
Jonathan King, Alireza Shahsafi, Zhen Zhang +7
Both the magnitude and spectrum of the blackbody-radiation distribution change with temperature. Here, we designed the temperature-dependent spectral emissivity of a coating to cou…
Tuning carrier density and phase transitions in oxide semiconductors using focused ion beams
Hongyan Mei, Alexander Koch, Chenghao Wan +10
We demonstrate spatial modification of the optical properties of thin-film metal oxides, zinc oxide and vanadium dioxide as representatives, using a commercial focused ion beam (FI…
Switchable induced-transmission filters enabled by vanadium dioxide
Chenghao Wan, David Woolf, Colin M. Hessel +6
Abstract: An induced-transmission filter (ITF) uses an ultrathin layer of metal positioned at an electric-field node within a dielectric thin-film bandpass filter to select one tra…
Efficient generation of optical bottle beams
Yuzhe Xiao, Zhaoning Yu, Raymond A. Wambold +5
Optical bottle beams can be used to trap atoms and small low-index particles. We introduce a figure of merit for optical bottle beams, specifically in the context of optical traps,…
Planck spectroscopy
Yuzhe Xiao, Chenghao Wan, Jad Salman +4
All spectrometers rely on some mechanism to achieve spectral selectivity; common examples include gratings, prisms, and interferometers with moving mirrors. We experimentally demon…
Hyperspectral interference tomography of nacre
Jad Salman, Cayla A. Stifler, Alireza Shahsafi +12
Structural characterization of biologically formed materials is essential for understanding biological phenomena and their environment, and generating new bio-inspired engineering…
Adjoint-optimized nanoscale light extractor for nitrogen-vacancy centers in diamond
Raymond A. Wambold, Zhaoning Yu, Yuzhe Xiao +7
We designed a nanoscale light extractor (NLE) for efficient outcoupling and beaming of broadband light emitted by shallow, negatively charged nitrogen-vacancy (NV) centers in bulk…
Infrared polarizer based on direct coupling to surface-plasmon polaritons
A. Shahsafi, J. Salman, B. E. Rubio Perez +3
We propose a new type of reflective polarizer based on polarization-dependent coupling to surface-plasmon polaritons (SPPs) from free space. This inexpensive polarizer is relativel…
Ultrathin broadband reflective optical limiter
Chenghao Wan, Zhen Zhang, Jad Salman +7
Optical limiters are nonlinear devices that feature decreasing transmittance with increasing incident optical intensity, and thus can protect sensitive components from high-intensi…
Guidelines for measurement of thermal emission
Yuzhe Xiao, Chenghao Wan, Alireza Shahsafi +7
Thermal emission is the radiation of electromagnetic waves from hot objects. The promise of thermal-emission engineering for applications in energy harvesting, radiative cooling, a…
Depth thermography: non-invasive 3D temperature profiling using infrared thermal emission
Yuzhe Xiao, Chenghao Wan, Alireza Shahsafi +2
We introduce a technique based on infrared thermal emission, termed depth thermography, that can remotely measure the temperature distribution beneath the surface of certain object…
Wide-angle spectrally selective absorbers and thermal emitters based on inverse opals
Alireza Shahsafi, Graham Joe, Soeren Brandt +8
Engineered optical absorbers are of substantial interest for applications ranging from stray light reduction to energy conversion. We demonstrate a large-area (centimeter-scale) me…
Temperature-independent thermal radiation
Alireza Shahsafi, Patrick Roney, You Zhou +11
Thermal emission is the process by which all objects at non-zero temperatures emit light, and is well-described by the classic Planck, Kirchhoff, and Stefan-Boltzmann laws. For mos…
Optical properties of thin-film vanadium dioxide from the visible to the far infrared
Chenghao Wan, Zhen Zhang, David Woolf +13
The insulator-to-metal transition (IMT) in vanadium dioxide (VO2) can enable a variety of optics applications, including switching and modulation, optical limiting, and tuning of o…
Nanosecond mid-infrared pulse generation via modulated thermal emissivity
Yuzhe Xiao, Nicholas A. Charipar, Jad Salman +2
We demonstrate the generation of nanosecond mid-infrared pulses via fast modulation of thermal emissivity, enabled by the absorption of visible pump pulses in unpatterned silicon a…
Multi-refractive-index metamaterials based on subwavelength waveguide arrays
Zhaoning Yu, Chenghao Wan, Jad Salman +4
We demonstrate a metamaterial that cannot be described by a single set of refractive-index and impedance values, even for fixed frequency and polarization. The metamaterial structu…
Thermal-emission measurements near room temperature using Fourier-transform infrared spectroscopy
Yuzhe Xiao, Alireza Shahsafi, Chenghao Wan +5
Accurate characterization of thermal emitters can be challenging due to the presence of background thermal emission from components of the experimental setup and the surrounding en…
Nanophotonic engineering of far-field thermal emitters
Denis G. Baranov, Yuzhe Xiao, Igor A. Nechepurenko +3
Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often presented to be incoher…
Mid-infrared optics using dielectrics with refractive indices below unity
Alireza Shahsafi, Yuzhe Xiao, Jad Salman +4
Conventional transparent materials at optical frequencies have refractive index values (n) greater than unity -- most commonly between about 1 and 4. This paper explores optical ph…