Cavity QED with Multiple Hyperfine Levels

We calculate the weak-driving transmission of a linearly polarized cavity mode strongly coupled to the D2 transition of a single Cesium atom. Results are relevant to future experiments with microtoroid cavities, where the single-photon Rabi frequency g exceeds the excited-state hyperfine splittings, and photonic bandgap resonators, where g is greater than both the excited- and ground-state splitting.Comment: 6 pages, 10 figure

Low threshold CW Nc laser oscillator at 1060 nm study

A broad range of characteristics of neodymium/yag lasers were investigated. With Nd:YVO4 crystals, CW 1.06 mu lasers were operated with thresholds a factor of 2 lower than Nd:YAG and with greater slope efficiencies. Thus, the first step in the development of new oscillators suitable for application in high data rate laser communication systems which surpass the present performance of the Nd:YAG laser has been successfully demonstrated

Minimax bounds for sparse PCA with noisy high-dimensional data

We study the problem of estimating the leading eigenvectors of a high-dimensional population covariance matrix based on independent Gaussian observations. We establish a lower bound on the minimax risk of estimators under the $l_2$ loss, in the joint limit as dimension and sample size increase to infinity, under various models of sparsity for the population eigenvectors. The lower bound on the risk points to the existence of different regimes of sparsity of the eigenvectors. We also propose a new method for estimating the eigenvectors by a two-stage coordinate selection scheme.Comment: 1 figur

On Approaching the Ultimate Limits of Photon-Efficient and Bandwidth-Efficient Optical Communication

It is well known that ideal free-space optical communication at the quantum limit can have unbounded photon information efficiency (PIE), measured in bits per photon. High PIE comes at a price of low dimensional information efficiency (DIE), measured in bits per spatio-temporal-polarization mode. If only temporal modes are used, then DIE translates directly to bandwidth efficiency. In this paper, the DIE vs. PIE tradeoffs for known modulations and receiver structures are compared to the ultimate quantum limit, and analytic approximations are found in the limit of high PIE. This analysis shows that known structures fall short of the maximum attainable DIE by a factor that increases linearly with PIE for high PIE. The capacity of the Dolinar receiver is derived for binary coherent-state modulations and computed for the case of on-off keying (OOK). The DIE vs. PIE tradeoff for this case is improved only slightly compared to OOK with photon counting. An adaptive rule is derived for an additive local oscillator that maximizes the mutual information between a receiver and a transmitter that selects from a set of coherent states. For binary phase-shift keying (BPSK), this is shown to be equivalent to the operation of the Dolinar receiver. The Dolinar receiver is extended to make adaptive measurements on a coded sequence of coherent state symbols. Information from previous measurements is used to adjust the a priori probabilities of the next symbols. The adaptive Dolinar receiver does not improve the DIE vs. PIE tradeoff compared to independent transmission and Dolinar reception of each symbol.Comment: 10 pages, 8 figures; corrected a typo in equation 3

The Richter Site (47DR80): a Millennium of Prehistoric Technological and Cultural Change on Washington Island, Door County, Wisconsin

The Richter site (47DR80) was excavated by University of Wisconsin-Milwaukee archaeological field schools during the summers of 1968 and 1973 under the direction of Guy Gibbon and G. Richard Peske. This site was identified by excavators as a North Bay Middle Woodland culture occupation based on Ronald Mason’s typology created from his work at the Mero and Porte des Morts sites on Wisconsin’s Door Peninsula. Although various specialized analyses have focused on aspects of the Richter site material culture, no site report or overall analysis of material culture exists. This study provides the first synthetic account of the UWM excavations and the associated material culture recovered from the site. Examination of ceramic materials from the Richter site document differences in ceramic production methods at the site. Paddle and anvil construction, using a cordmarked paddle, date to Early Woodland occupations at the site. Coil building, resulting in smoothed surfaced Laurel-like vessels, date to the Middle Woodland. The results indicate the need for changes to the existing North Bay taxon to include greater time depth and changes in manufacturing technology. Variations in the decisions of potters are documented and discussed utilizing a performance-based life history approach

Trapped atoms in cavity QED: coupling quantized light and matter

On the occasion of the hundredth anniversary of Albert Einstein's annus mirabilis, we reflect on the development and current state of research in cavity quantum electrodynamics in the optical domain. Cavity QED is a field which undeniably traces its origins to Einstein's seminal work on the statistical theory of light and the nature of its quantized interaction with matter. In this paper, we emphasize the development of techniques for the confinement of atoms strongly coupled to high-finesse resonators and the experiments which these techniques enable

Distribution and growth dynamics of invasive goldenrod (Solidago canadensis) in its introduced range in Estonia, and some Australian comparisons

Understanding the distribution and population dynamics of invasive plant species is fundamental to our capacity to appropriately predict and manage plant invasions. The invasion biology of non-native Solidago canadensis in Estonia was investigated for the first time by assessing its distribution patterns and growth dynamics. First, fifty-two peri-urban populations were surveyed, and population location, size, adjacent communities, number of shoots as well as shoot height were recorded. Then, thirty genets were excavated from previously surveyed populations in order to analyze their age and growth traits in the vicinity of Tartu. The majority of S. canadensis populations were small, i.e. occupying less than 50 m2, had 1 to 50 plants per population and were located predominantly on disturbed roadsides. The surveyed populations were young, with the average age of genets estimated to be five years at the time of sampling in 2006. We suggest that S. canadensis is well adapted to a wide range of habitats but predominantly occurs in human-disturbed habitats adjacent to settlements and roads. We found that Solidago canadensis genet age did not affect significantly its growth traits suggesting that growth traits are similar between younger and older genets