Imaging-based Parametric Resonance in an Optical Dipole Atom Trap

We report sensitive detection of parametric resonances in a high-density sample of ultracold $^{87}Rb$ atoms confined to a far-off-resonance optical dipole trap. Fluorescence imaging of the expanded ultracold atom cloud after a period of parametric excitation shows significant modification of the atomic spatial distribution and has high sensitivity compared with traditional measurements of parametrically-driven trap loss. Using this approach, a significant shift of the parametric resonance frequency is observed, and attributed to the anharmonic shape of the dipole trap potential

Optical Properties& Energy Transfer Dynamics of Atmospheric Species

Our research group is interested in how light interacts with small molecules and particulate matter that are important to atmospheric chemistry and climate change. An active project currently being performed in the James Madison University Undergraduate Laser Laboratory involves a detailed mapping of energy transfer rates from excited or metastable states of atomic or molecular species. This talk describes a specific example study with potential relevance to the JLAMP VUV/Soft X-ray User Facility that would investigate relaxation dynamics of metastable Krypton atoms using two-photon photoacoustic spectroscopy at 819 nm and 124 nm. A study like this would provide useful reference data to support future development of sensitive trace analyzers for noble gas isotopes

Stevens v. City of Cannon Beach: Does Oregon\u27s Doctrine Of Custom Find A Way Around Lucas?

The Oregon Supreme Court recently issued an en banc decision in Stevens v. City of Cannon Beach affirming a court of appeals decision to dismiss plaintiffs\u27 claim of inverse taking. In so doing, the court confirmed its holding in State cc rel. Thornton v. Hay that a public easement for recreation exists in the dry sand areas of the state\u27s beaches under the doctrine of custom. The Stevens court stated that because custom as applied to Oregon\u27s ocean shores merely enunciates the background principles of ... the law of property, its decision comported with the United States Supreme Court holding in Lucas v. South Carolina Coastal Council. Lucas is the most recent in a long line of Supreme Court takings decisions. In that case, the Court applied what it termed a second categorical rule and held that confiscatory regulations, those [w]here the owner of real property has been called upon to sacrifice all economically beneficial uses in the name of the common good, ... were per se takings and required compensation. The Court qualified this categorical rule, however, and declared that it would not be applied when the proscribed use interests were not part of [the property owner\u27s] title to begin with.” Decided just one year after Lucas, the Stevens case appears to test the same constitutional question. A major distinction between the cases, however, is in the method that each state used to assert public rights in otherwise privately owned property. South Carolina relied solely upon its police powers to proscribe certain harmful uses of coastal property through enactment of the Beachfront Management Act. In contrast, the Oregon court affirmed the public\u27s rights in the state\u27s shorelands by finding that under the doctrine of custom the public always had a right to use the dry sand area of Oregon\u27s beaches. Under this theory, the statutes encompassed in Oregon\u27s Beach Bill serve only to codify the limitations which inhere in the land, by virtue of state property law, and do not newly legislate] or decree[] \u27 limitations on property rights. Whether the doctrine of custom is a state property law that can withstand constitutional scrutiny is the subject of this Note. The search for answers to this inquiry begins with a review of the doctrine of custom, both through its common law history and a survey of the more recent decisions on the subject. The Note then analyzes Oregon\u27s doctrine of custom and the application of this doctrine in light of the Supreme Court\u27s takings analysis in Lucas

Race on Campus: Debunking Myths with Data

There are many myths revolving race and diversity on college campuses. Are students of color choosing to isolate themselves in ways that hurt them? Did your friend from high school only get into Harvard because she’s Black? Does the SAT inherently favor rich kids? In Race on Campus: Debunking Myths with Data, Julie Park describes and deconstructs racial myths in an incredible contribution to the higher education literature on race, racism, and diversity issues on campus

Solar Refrigeration Project

The goal of this project was to design and build a milk refrigerator that could work off-the-grid. The refrigerator was designed to have the capacity to maintain freshness of 25 liters of milk, or half of the daily milk yield. Rural farmers are forced to either discard their “evening milk,” or milk produced by cows in the evening, or sell it at a fraction of the market price of milk due to deteriorating quality. With the assistance of the refrigerator in this study, rural farmers in sub-Saharan will be able to sell their “evening milk” the next morning at full value without worry of it spoiling overnight

Coherent backscattering under conditions of electromagnetically induced transparency

We consider the influence of a resonant control field on weak localization of light in ultracold atomic ensembles. Both steady-state and pulsed light excitation are considered. We show that the presence of a control field essentially changes the type of interference effects which occur under conditions of multiple scattering. For example, for some scattering polarization channels the presence of a control field can cause destructive interference through which the enhancement factor, normally considered to be greater than one, becomes less than one.Comment: Submitted to Journal of Modern Optics, Special Issue: Proceedings of PQE 201