Universal Three Dimensional Optical Logic

Modern integrated circuits are essentially two-dimensional (2D). Partial three-dimensional (3D) integration and 3D-transistor-level integrated circuits have long been anticipated as routes to improve the performance, cost and size of electronic computing systems. Even as electronics approach fundamental limits however, stubborn challenges in 3D circuits, and innovations in planar technology have delayed the dimensional transition. Optical computing offers potential for new computing approaches, substantially greater performance and would complement technologies in optical interconnects and data storage. Nevertheless, despite some progress, few proposed optical transistors possess essential features required for integration into real computing systems. Here we demonstrate a logic gate based on universal features of nonlinear wave propagation: spatiotemporal instability and collapse. It meets the scaling criteria and enables a 3D, reconfigurable, globally-hyperconnected architecture that may achieve an exponential speed up over conventional platforms. It provides an attractive building block for future optical computers, where its universality should facilitate flexible implementations.Comment: manuscript (5 pages, 3 figures) with supplementary information (6 pages, 5 figures

A Broadband Scalar Vortex Coronagraph

Broadband coronagraphy with deep nulling and small inner working angle has the potential of delivering images and spectra of exoplanets and other faint objects. In recent years, many coronagraphic schemes have been proposed, the most promising being the optical vortex phase mask coronagraphs. In this paper, a new scheme of broadband optical scalar vortex coronagraph is proposed and characterized experimentally in the laboratory. Our setup employs a pair of computer generated phase gratings (one of them containing a singularity) to control the chromatic dispersion of phase plates and achieves a constant peak-to-peak attenuation below $1\cdot 10^{-3}$ over a bandwidth of 120 nm centered at 700 nm. An inner working angle of ~\lambda/D is demonstrated along with a raw contrast of 11.5 magnitudes at 2\lambda/D.Comment: Accepted, 6 pages, 6 image

A compact, multi-pixel parametric light source

The features of a compact, single pass, multi-pixel optical parametric generator are discussed. Several hundreds of independent high spatial-quality tunable ultrashort pulses were produced by pumping a bulk lithium triborate crystal with an array of tightly focussed intense beams. The array of beams was produced by shining a microlenses array with a large pump beam. Overall conversion efficiency to signal and idler up to 30% of the pump beam has been reported. Shot-to-shot energy fluctuation down to 3% was achieved for the generated radiation.Comment: 11 pages, 6 figures, submitted to "Optics Communications

El franquismo a la luz de sus metáforas

This essay will analyse Francisco Franco’s «mensajes de fin de año» (end of year discourses) during his mandate (1939-1953) (1953-1966) and (1966-1974). The principal aim is to elucidate how the speaker shows himself in these political discourses by constructing the discursive object «hispanidad» (hispanic essence). Following that aim we will analyse the orientational metaphors, supported by a biblical interdiscourse, and ontological ones, based on the semantic field of economic production, specially in the second stage. The period of francoism is characterized in three stages. The first one, by the usage of the term «hispanidad» (hispanic essence) as the sense of christian resistence and sacrifice and by the topic of «la hora difícil» (the hard hour). These discourses recover the discursive memory of José Antonio from Falange tradicionalista. Another element is the construction of the usa as an enemy because of the economic system based on Autarchism while the regime is presented as a dictatorship. The second stage constructs the «hispanidad» (hispanic essence) by using the semantic filed of economic production. The christian home is a place capable of producing and reproducing itself. The conception of dictatorship by which the Regime was presented itself is now characterized as a Monarchy. The last stage is constructed by the semantic equivalence «hispanidad» (hispanic esssence)- greatness and historical truth. With the loe (Organic Law of State) these discourses try to construct a new legality, different from the illustrated men of the xviii and the Cadiz Constitution.Este artículo tiene por objeto el análisis de los discursos del General Francisco Franco, cuyo mandato se extiende desde 1939 hasta su muerte en 1975. Es un período que podría clasificarse en tres fases. La primera etapa se caracteriza por la utilización del concepto hispanidad desde el sentido de resistencia y sacrificio cristiano (cuyo tópico característico es el de la hora difícil). Estos discursos recuperan con mayor fidelidad la memoria discursiva que plantea y construye el ideal joseantoniano de Falange Tradicionalista. Otro rasgo es la construcción que se realiza de Estados Unidos en tanto enemigo por no poseer un sistema económico autárquico mientras que la caracterización del Movimiento se presenta discursivamente como Régimen. La segunda etapa construye la hispanidad mediante el campo semántico de la producción económica. El hogar cristiano y abnegado será un hogar capaz de producir y multiplicarse. Se abandona la denominación régimen por monarquía. La última etapa se construye mediante la equivalencia semántica hispanidad/grandeza y verdad históricas. Con la loe los discursos intentan construir una nueva legalidad, distinta a las bases iniciadas por los ilustrados y la constitución de Cádiz