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OBJECTIVES A previous study demonstrated that when one knee is artificially immobilized, a contralateral shoe-lift improves the oxygen cost of walking. This study was undertaken to evaluate the kinematic and kinetic effects associated with this shoe-lift. DESIGN Motion analysis and force platform data were collected in subjects walking (1) normally, (2)… (More)
OBJECTIVE To create a statistical model using three-dimensional (3D) head kinematics and range of motion (ROM) to distinguish between people with whiplash syndrome and asymptomatic controls. STUDY DESIGN Cross-sectional study to estimate validity of diagnostic measures. METHODS Fifty-one asymptomatic controls (most of whom were women), 18-35 yr old and… (More)
The optical properties of periodic arrays of subwavelength apertures in metal films on GaAs substrates are studied. Specifically, geometric and material losses for these plasmonic structures are characterized using angular dependent transmission, normal incidence reflection, and angular dependent diffraction experiments, in addition to a crossed-polarizer… (More)
A goal of many physiatric interventions is to improve biomechanical walking efficiency. Thus, a tool that helps assess this efficiency, independent of cardiac, pulmonary, psychologic, or other nonbiomechanical factors, would be useful. Currently used methods to measure efficiency, including comfortable walking speed, are not specific to biomechanical… (More)
We present a new type of electrically tunable strong coupling between planar metamaterials and epsilon-near-zero modes that exist in a doped semiconductor nanolayer. The use of doped semiconductors makes this strong coupling tunable over a wide range of wavelengths through the use of different doping densities. We also modulate this coupling by depleting… (More)
We demonstrate strong coupling between a surface plasmon and intersublevel transitions in self-assembled InAs quantum dots. The surface plasmon mode exists at the interface between the semiconductor emitter structure and a periodic array of holes perforating a metallic Pd/Ge/Au film that also serves as the top electrical contact for the emitters. Spectrally… (More)
We demonstrate room temperature midinfrared electroluminescence from intersublevel transitions in self-assembled InAs quantum dots. The dots are grown in GaAs/AlGaAs heterostructures designed to maximize current injection into dot excited states while preferentially removing electrons from the ground states. As such, these devices resemble quantum cascade… (More)
We demonstrate all-semiconductor thin-film plasmonic absorbers, where strong absorption in these structures is linked to the excitation of highly-confined negative-index surface plasmon polaritons. We present numerical and analytical descriptions of guided modes of the system.
Direct rectification of electromagnetic radiation is a well-established method for wireless power conversion in the microwave region of the spectrum, for which conversion efficiencies in excess of 84% have been demonstrated. Scaling to the infrared or optical part of the spectrum requires ultrafast rectification that can only be obtained by direct… (More)
We fabricate subwavelength varying periodicity toothed metal-insulator-metal waveguides for mid-infrared frequencies. The transmission spectra of these structures for TM and TE polarized light is investigated, and our results compared to numerical simulations.