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Michael T. Stocker, Bryan M. Barnes, Martin Y. Sohn, Eric S. Stanfield, Richard M. Silver
Widespread commercialization of proton exchange membrane fuel cells remains curbed by various manufacturing and infrastructure challenges. One such technical barrier identified by the U. S. Department of Energy is the need for high-speed, in-line process
Brandon Lane, Steven Grantham, Ho Yeung, Clarence Zarobila, Jason Fox
Researchers and equipment manufacturers are developing in-situ process monitoring techniques with the goal of qualifying additive manufacturing (AM) parts during a build, thereby accelerating the certification process. Co-axial melt pool monitoring (MPM)
Jacob M. Taylor, Kim Seunghwi, Xu Xunnong, Gaurav Bahl
The transport of sound and heat, in the form of phonons, is fundamentally limited by disorder-induced scattering. In electronic and optical settings, introduction of chiral transport - in which carriers have unidirectional propagation - provides robustness
Margaret Z. Dominguez, David Content, Qian Gong, Ulf Griesmann, John Hagopian, Catherine Marx, Arthur Whipple
Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey
Ryan Beams, Jeremiah W. Woodcock, Jeffrey W. Gilman, Stephan J. Stranick
We demonstrate a multimodal superresolution microscopy technique based on a phase masked excitation beam in combination with spatially filtered detection. The theoretical foundation for calculating the focus from a non-paraxial beam with an arbitrary
Ivan Ryger, Paul A. Williams, Nathan A. Tomlin, Alexandra B. Artusio-Glimpse, Michelle S. Stephens, Matthew T. Spidell, John H. Lehman
Measurement of high optical power using radiation pressure sensing [1] is attractive for its non-absorbing power measurment allowing compact sensor dimensions, faster response times and negligible optical power dissipation compared to standard thermal
Elliott Brown, A. Mingardi, W-D. Zhang, Ari Feldman, Todd E. Harvey, Richard Mirin
We present a study of room-temperature, ultrafast photoconductivity associated with strong, sub-bandgap, resonant absorption around lamba} = 1550 nm in three MBE-grown GaAs epitaxial layers heavily doped with Er at concentrations of ≅2.9 x 10 18 (control
Kenneth Voss, Howard Gordon, Stephanie J. Flora, B. Carol Johnson, Mark A. Yarbrough, Michael Feinholz, Terrance Houlihan
The upwelling radiance attenuation coefficient (KLu) in the upper 10 m of the water column can be significantly influenced by inelastic scattering processes, and thus will vary even with homogeneous water properties. The Marine Optical BuoY (MOBY), the
Nicolas Marquez Peraca, D T. Bilir, Behrang Hamadani
The frequency dependence of the external quantum efficiency (EQE) of high-quality multijunction solar cells was examined by the modulated photocurrent spectroscopy method via an optical setup comprised of a light-pipe-coupled compact LED array. The optical
Michael Feinholz, B. Carol Johnson, Kenneth Voss, Mark A. Yarbrough, Stephanie J. Flora
The immersion coefficient accounts for the difference in calibration for a radiometer placed in the air versus water or another medium. The immersion coefficient for the radiance collectors on the Marine Optical BuoY (MOBY) were modeled and measured. The
Lixiang Xu, Judith Specht, Philip Nagler, Kha Tran, Akshay Singh, Chandriker K. Dass, Andreas Knorr, Xiaoqin Li, Galan Moody
In atomically thin transition metal dichalcogenides (TMDs), reduced dielectric screening of the Coulomb interaction leads to strongly correlated many-body states, including excitons and trions, that dominate the optical properties. Higher-order states
We present a software package aimed at simulating photon-number probability distributions of a range of naturally occurring classical and non-classical states of light. This software can generate arbitrary probability distributions based on the known mode
Yiliang Bao, Feng Zhou, Thomas W. LeBrun, Jason J. Gorman
A detailed study of the fabrication of silicon concave micromirrors for hemispherical microcavities is presented that includes fabrication yield, surface quality, surface roughness, cavity depth, radius of curvature, and the aspect ratio between the cavity
This study considers a physics-based and a kernel-based approach for characterizing pixels in a scene that may be linear (areal mixed) or nonlinear (intimately mixed). The physics-based method is based on earlier studies that indicate nonlinear mixtures in
This article reviews the mechanism of tip enhanced Raman spectroscopy (TERS) and its importance for characterizing graphene. The theoretical foundation of TERS and experimental implementation are discussed. Conventionally, Raman scattering is treated as a
Shaokang Wang, Stefan Droste, Laura C. Sinclair, Ian R. Coddington, Nathan R. Newbury, Curtis R. Menyuk
Passively modelocked lasers with semiconductor saturable absorption mirrors (SESAMs) are attractive comb sources since they can be made environmentally stable, but they become unstable when the group velocity dispersion is too low or the gain is too high
Catherine C. Cooksey, David W. Allen, Benjamin K. Tsai
This data set contains 100 reference reflectance spectra of human skin, spanning the wavelength region from 250 nm to 2500 nm. The spectra were acquired with a commercial spectrophotometer and are directly traceable to the national scale for directional
Kai Hao, Lixiang Xu, Wu Fengcheng, Philip Nagler, Kha Tran, Xin Ma, Tobias Korn, Allan H. MacDonald, Xiaoqin Li, Galan Moody
The emerging field of valleytronics aims to exploit the valley pseudospin of electrons residing near Bloch band extrema as an information carrier. Recent experiments demonstrating optical generation and manipulation of exciton valley coherence (the
A systematic study is presented of the intensity-dependent nonlinear light scattering spectra of gold nanorods under resonant excitation of the longitudinal surface plasmon resonance (SPR). The spectra exhibit features due to coherent second and third
Understanding the changes in the microstructures and structures of clays with varying intercalated metal ions at elevated temperatures is of importance for many applications ranging from engineering materials such as ceramics for fuel cell applications to
Laura C. Sinclair, Ian R. Coddington, William C. Swann, Kana Iwakuni, Nathan R. Newbury
We demonstrate a completely polarization-maintaining fiber frequency comb operating at a 200 MHz repetition rate and show stability and noise performance consistent with precision measurement applications. This design is compatible with a robust, fieldable
Jeffrey M. Shainline, Sonia M. Buckley, Nima Nader, Cale M. Gentry, Kevin C. Cossel, Milos A. Popovic, Nathan R. Newbury, Richard P. Mirin
We present an approach to fabrication and packaging of integrated photonic devices that utilizes waveguide and detector layers deposited at near-ambient temperature. All lithography is performed with a 365 nm i-line stepper, facilitating low cost and high
Alexander Yulaev, Hongxuan Guo, Evgheni Strelcov, Lei Chen, Ivan Vlasssiouk, Andrei Kolmakov
An atomic-scale thickness, molecular impermeability, low atomic number, and mechanical strength make graphene an ideal electron transparent membrane for scanning electron microscopy and spectroscopy in liquids. Here, we present a novel sample platform made
Paul Lemaillet, Jeeseong Hwang, Heidrun Wabnitz, Dirk Grosenick, Lin Yang, David W. Allen
Diffuse materials that approximate the optical properties of human tissue are commonly used as phantoms. In order to use the phantoms in a manner that provides consistent results relative to independent measurements, the optical properties need to be tied