COPE Clinic Relocates to South Oxford Center

Move to larger space allows UM facility to better serve Oxford and campus communit

Pupil remapping for high contrast astronomy: results from an optical testbed

The direct imaging and characterization of Earth-like planets is among the most sought-after prizes in contemporary astrophysics, however current optical instrumentation delivers insufficient dynamic range to overcome the vast contrast differential between the planet and its host star. New opportunities are offered by coherent single mode fibers, whose technological development has been motivated by the needs of the telecom industry in the near infrared. This paper presents a new vision for an instrument using coherent waveguides to remap the pupil geometry of the telescope. It would (i) inject the full pupil of the telescope into an array of single mode fibers, (ii) rearrange the pupil so fringes can be accurately measured, and (iii) permit image reconstruction so that atmospheric blurring can be totally removed. Here we present a laboratory experiment whose goal was to validate the theoretical concepts underpinning our proposed method. We successfully confirmed that we can retrieve the image of a simulated astrophysical object (in this case a binary star) though a pupil remapping instrument using single mode fibers.Comment: Accepted in Optics Expres

Tomographic reconstruction of quantum states in N spatial dimensions

Most quantum tomographic methods can only be used for one-dimensional problems. We show how to infer the quantum state of a non-relativistic N-dimensional harmonic oscillator system by simple inverse Radon transforms. The procedure is equally applicable to finding the joint quantum state of several distinguishable particles in different harmonic oscillator potentials. A requirement of the procedure is that the angular frequencies of the N harmonic potentials are incommensurable. We discuss what kind of information can be found if the requirement of incommensurability is not fulfilled and also under what conditions the state can be reconstructed from finite time measurements. As a further example of quantum state reconstruction in N dimensions we consider the two related cases of an N-dimensional free particle with periodic boundary conditions and a particle in an N-dimensional box, where we find a similar condition of incommensurability and finite recurrence time for the one-dimensional system.Comment: 8 pages, 1 figur

Assessment of Program Delivery to Small Farmers: Fax Information Center System at Satellite Locations

Due to the many variables associated with small and part-time farmers, such as widely ranging educational levels and available time applied to farming, effectively providing extension information to this group of farmers can be quite difficult. The use of innovative, program delivery methods for reaching small and part-time farmers has been tried in several North Carolina counties with variable success. One means of reaching these special audiences is a satellite information center at agribusiness or other locations away from the extension office itself. A fax request system prominently placed directly in these satellite locations has produced widely variable results in level of use from the perspective of requests for information originating from the centers. Yet, where the centers have been used for both an information request system and an informational bulletin board with timely information sent to the centers from Cooperative Extension for posting on the bulletin boards, the results have been very favorable. While many factors have been found to affect the success of individual locations, the fax satellite centers appear to be able to provide a niche for innovative program delivery by extension and can have highly beneficial side effects of positively marketing the extension programs in the respective counties

Full characterization of Gaussian bipartite entangled states by a single homodyne detector

We present the full experimental reconstruction of Gaussian entangled states generated by a type--II optical parametric oscillator (OPO) below threshold. Our scheme provides the entire covariance matrix using a single homodyne detector and allows for the complete characterization of bipartite Gaussian states, including the evaluation of purity, entanglement and nonclassical photon correlations, without a priori assumptions on the state under investigation. Our results show that single homodyne schemes are convenient and robust setups for the full characterization of OPO signals and represent a tool for quantum technology based on continuous variable entanglement.Comment: 4 pages, 3 figures, slightly longer version of published PR

Evaluation of the ET2000 Guardrail End Treatment

The objectives of this study were to monitor and report the performance of the ET2000 guardrail end treatment design in traffic accidents. Data for a total of 34 collisions involving the ET2000 were identified. In most cases, an accident report was obtained and the damaged guardrail was inspected. The involved vehicle was inspected when available. Proper or improper performance of end treatments in the collisions were judged based on whether it performed as designed. Field performance of the ET2000, as documented in traffic accidents, shows that, considering all the impacts, this end treatment has performed properly. In several instances the end treatment bent, rather than being pushed straight back, during the collision. This could typically be related to the angle at which impact occurred. Results warrant continued use of this end treatment. However, its cost would not justify a widespread use on all types of highways

The R Aquarii System at Optical and Radio Wavelengths

Observations of the symbiotic binary R Aquarii environment were obtained with the Very Large Array (VLA) at 2, 6, and 20 em at the same epoch. The observed spectral index and strong linear polarization reveal that emission from the compact double radio source discovered in previous observations is nonthermal; thus, this source is not associated with R Aquarii but is an extragalactic background object. The spectral index of the compact nebula surrounding R Aquarii indicates that the emission is thermal and the nebula is ionized by an unseen, hot companion to the Mira-like variable R Aquarii. As expected, this region shows no indication of linear polarization, and we have determined a steady state mass loss of ~ 2. 7 x 10- 7 M 0 yr- 1 from the system. However, the spectral index and polarization observations of the extended jet ~6 away from R Aquarii indicate that this amorphous source is definitely thermal and optically thin in nature. These new observations place severe constraints on possible models which have been proposed from previous investigations. We suggest that our new observations of the jet can be best explained by enhanced mass exchange occurring periodically in the symbiotic system. Comparison of 6 em data taken with the same VLA configuration but separated by 495 days does not indicate any appreciable morphological change or statistically significant integrated flux difference and thus suggests that on these time scales the jet is now quite stable. High-resolution white light images of R Aquarii and environs obtained with the 4 m telescope at Kitt Peak just prior to the VLA observations show a high degree of correlation with the 6 em radio data and place a limit on the apparent visual magnitude of the compact double radio source; optical speckle interferometry failed to resolve any components in the R Aquarii system