Spatio-temporal second-order quantum correlations of surface plasmon polaritons

We present an experimental methodology to observe spatio-temporal second-order quantum coherence of surface plasmon polaritons which are emitted by nitrogen vacancy color centers attached at the apex of an optical tip. The approach relies on leakage radiation microscopy in the Fourier space and we use this approach to test wave-particle duality for surface plasmon polaritons

Near-field microscopy with a scanning nitrogen-vacancy color center in a diamond nanocrystal: A brief review

We review our recent developments of near-field scanning optical microscopy (NSOM) that uses an active tip made of a single fluorescent nanodiamond (ND) grafted onto the apex of a substrate fiber tip. The ND hosting a limited number of nitrogen-vacancy (NV) color centers, such a tip is a scanning quantum source of light. The method for preparing the ND-based tips and their basic properties are summarized. Then we discuss theoretically the concept of spatial resolution that is achievable in this special NSOM configuration and find it to be only limited by the scan height over the imaged system, in contrast with the standard aperture-tip NSOM whose resolution depends critically on both the scan height and aperture diameter. Finally, we describe a scheme we have introduced recently for high-resolution imaging of nanoplasmonic structures with ND-based tips that is capable of approaching the ultimate resolution anticipated by theory.Comment: AD, AC, OM, MB and SH wish to dedicate this brief review article to their co-author and colleague Yannick Sonnefraud who passed away in September 2014. Yannick initiated this research in 200

A survey of laser lightning rod techniques

The work done to create a laser lightning rod (LLR) is discussed. Some ongoing research which has the potential for achieving an operational laser lightning rod for use in the protection of missile launch sites, launch vehicles, and other property is discussed. Because of the ease with which a laser beam can be steered into any cloud overhead, an LLR could be used to ascertain if there exists enough charge in the clouds to discharge to the ground as triggered lightning. This leads to the possibility of using LLRs to test clouds prior to launching missiles through the clouds or prior to flying aircraft through the clouds. LLRs could also be used to probe and discharge clouds before or during any hazardous ground operations. Thus, an operational LLR may be able to both detect such sub-critical electrical fields and effectively neutralize them

Directional and singular surface plasmon generation in chiral and achiral nanostructures demonstrated by Leakage Radiation Microscopy

In this paper, we describe the implementation of leakage radiation microscopy (LRM) to probe the chirality of plasmonic nanostructures. We demonstrate experimentally spin-driven directional coupling as well as vortex generation of surface plasmon polaritons (SPPs) by nanostructures built with T-shaped and $\Lambda$- shaped apertures. Using this far-field method, quantitative inspections, including directivity and extinction ratio measurements, are achieved via polarization analysis in both image and Fourier planes. To support our experimental findings, we develop an analytical model based on a multidipolar representation of $\Lambda$- and T-shaped aperture plasmonic coupler allowing a theoretical explanation of both directionality and singular SPP formation. Furthermore, the roles of symmetry breaking and phases are emphasized in this work. This quantitative characterization of spin-orbit interactions paves the way for developing new directional couplers for subwavelength routing

Balance Fiscal Estructural y Cíclico del Gobierno Nacional Central de Colombia, 1980-2002

Tener conocimiento del balance fiscal estructural es importante tanto para el análisis como para la formulación ex ante de la política fiscal. En este documento proponemos una metodología para la determinación del balance estructural de las finanzas del Gobierno Nacional Central, basados en el procedimiento estándar del FMI. La metodología se construye a partir del cálculo del balance estructural total y primario, con sus correspondientes balances cíclicos, para el período 1980-2002. Utilizamos diferentes técnicas econométricas para la estimación de parámetros relevantes. Los resultados indican que a comienzos de la década de los ochenta y de los noventa el balance fiscal estructural del gobierno estuvo por encima del observado, es decir, el gobierno tuvo un menor déficit o mayor superávit, en una magnitud entre 0.1% y 0.4% del PIB, debido a los movimientos cíclicos del PIB y/o las desviaciones de los precios del crudo por encima de su tendencia de largo plazo y/o por las menores erogaciones por transferencias territoriales. Para el resto del período de análisis sucedió lo contrario, es decir, el balance estructural del gobierno estuvo estuvo por debajo del observado, en una magnitud entre 0.2% y 0.4% del PIB. La magnitud de las diferencias lleva a la conclusión que el balance fiscal del gobierno central de Colombia es básicamente de naturaleza estructural, es decir, que no basta con que el país crezca a tasas iguales al potencial sino que se necesita mucho más esfuerzo (en ingresos y gastos) para ajustar las finanzas del gobierno.Balance Estructural; Balance Cíclico; Balance Ajustado; Transformación de Box-Cox; Cointegración; Estabilidad; Mínimos Cuadrados Recursivos.

Photophysics of single nitrogen-vacancy centers in diamond nanocrystals

International audienceA study of the photophysical properties of nitrogen-vacancy (NV) color centers in diamond nanocrystals of size 50 nm or below is carried out by means of second-order time-intensity photon correlation and cross-correlation measurements as a function of the excitation power for both pure charge states, neutral and negatively charged, as well as for the photochromic state, where the center switches between both states at any power. A dedicated three-level model implying a shelving level is developed to extract the relevant photophysical parameters coupling all three levels. Our analysis confirms the very existence of the shelving level for the neutral NV center. It is found that it plays a negligible role on the photophysics of this center, whereas it is responsible for an increasing photon bunching behavior of the negative NV center with increasing power. From the photophysical parameters, we infer a quantum efficiency for both centers, showing that it remains close to unity for the neutral center over the entire power range, whereas it drops with increasing power from near unity to approximately 0.5 for the negative center. The photophysics of the photochromic center reveals a rich phenomenology that is to a large extent dominated by that of the negative state, in agreement with the excess charge release of the negative center being much slower than the photon emission process

The Phylogeny and Biogeography of the Monito del Monte (Dromiciops Gliroides) and its Relatives

Marsupials are a group of mammals that give birth to young that are not fully developed. These offspring must complete the remainder of their development outside of the womb attached to their mother’s teat. Marsupials only occur in South America and Australasia, with one species extending into North America. The marsupial known as the monito del monte, which is Spanish for ‘little monkey of the mountain,’ (Dromiciops gliroides) is a South American marsupial; however, it shares a key morphological feature of ankle bone morphology with Australasian marsupials. This shared, derived trait is what defines the cohort Australidelphia, to which the four Australasian orders of marsupials and the monito del monte belong. Because of this placement, the monito del monte appears to be a link between the South American and Australasian marsupials. By reviewing phylogenetic studies on marsupials, fossil evidence, biogeography, and extinct and extant marsupial and placental mammals of Australasia and South America, it is anticipated that the evolutionary history of marsupials will be better understood. The role of the monito del monte is pivotal in this story. The close relationship between the monito del monte and the Australasian marsupials was strongly supported by molecular, biogeographic, and fossil evidence, in addition to morphology. This thesis hypothesized that an ancient American marsupial dispersed across the supercontinent Gondwana and gave rise to the Australidelphians. Subsequently, dispersal is what brought the monito del monte to South America. Therefore, the Australidelphians, including the monito del monte, originated in Australasia

Creating Harmony from Diversity: What Confucianism Reveals about the True Value of Liberal Education for the 21st Century

This paper takes inspiration from Confucius’s teachings on social harmony to suggest that the most salient defense of a liberal education is that it is the indispensible means by which to parlay our increasingly diverse student populations into a more harmonious global society for the 21st century and beyond. Given the ever-increasing diversity of local communities and the globality of our social and professional lives as the significance of political boundaries and local citizenship fades, traditional defenses of a liberal education on the grounds that it prepares students for meaningful participation in local democracies or that it abstractly enhances life satisfaction, while valid, are no longer sufficient. Realizing that Confucius understood diversity on many levels as essential to cultivating social and universal harmony may help to reveal greater contemporary relevance of his teachings and bolster advocacy for a liberal education