Wendell T. Hill

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A laser beam with phase singularities is an interesting object to study in optics and may have important applications in guiding atoms and molecules. We explore the characteristics of a singularity in a nondiffracting Bessel beam experimentally by use of a programmable spatial light modulator with 64-level phase holograms. The diffraction efficiency with(More)
We have created a long-lived (≈40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow(More)
We present two spatial-shaping approaches - phase and amplitude - for creating two-dimensional optical dipole potentials for ultracold neutral atoms. When combined with an attractive or repulsive Gaussian sheet formed by an astigmatically focused beam, atoms are trapped in three dimensions resulting in planar confinement with an arbitrary network of(More)
Title of Thesis: POLARIZATION-INSENSITIVE TECHNIQUES FOR OPTICAL SIGNAL PROCESSING Degree candidate: Reza Salem Degree and year: Doctor of Philosophy, 2006 Thesis directed by: Professor Thomas E. Murphy Department of Electrical and Computer Engineering This thesis investigates polarization-insensitive methods for optical signal processing. Two signal(More)
The background in saturation spectroscopy is decreased by balancing the probe beam, in amplitude and phase, against a second probe, using a configuration like a Jamin interferometer. This improves the signal-to-noise ratio. If the phase is adjustable to provide best balance while the laser is tuned, the signal is proportional to the square of the(More)
We report for the first time the ability to perform time resolved imaging of terahertz (THz) waves propagating within a Fabry-Perot resonator on a LiNbO<sub>3</sub> slab. Electro-optic effect is used to record the full spatiotemporal evolution of THz fields inside the resonator. In addition to revealing the real-space behavior, the data further demonstrate(More)
The energy spectrum of relativistic electrons is an important characterization of high intensity laser-matter interactions. We present a technique that utilizes Cerenkov radiation to measure the time-resolved energy distribution of electrons. Electrons escaping from targets irradiated by high-intensity laser pulses were measured, demonstrating the(More)
A laser beam with phase singularities is an interesting object to study in optics and may have important applications in guiding atoms and molecules. Here we explore the characteristics of a singularity in a nondiffracting Bessel beam experimentally, using a programmable spatial light modulator with 64 level phase holograms. The diffraction efficiency using(More)
Title of Thesis: POLARIZATION-INSENSITIVE TECHNIQUES FOR OPTICAL SIGNAL PROCESSING Degree candidate: Reza Salem Degree and year: Doctor of Philosophy, 2006 Thesis directed by: Professor Thomas E. Murphy Department of Electrical and Computer Engineering This thesis investigates polarization-insensitive methods for optical signal processing. Two signal(More)