253 citations · 556 across the 20 of their papers we have counts for
15 papers · 1 filter
Colossal optical anisotropy from atomic-scale modulations
Hongyan Mei, Guodong Ren, Boyang Zhao +17
In modern optics, materials with large birefringence (Δn, where n is the refractive index) are sought after for polarization control (e.g. in wave plates, polarizing beam splitters…
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…
Passive frequency conversion of ultraviolet images into the visible using perovskite nanocrystals
Jad Salman, Mahesh K. Gangishetty, Bryan E. Rubio-Perez +8
We demonstrate a passive down-conversion imaging system that converts broadband ultraviolet light to narrow-band green light while preserving the directionality of rays, and thus e…
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…
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…
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…