Linewidth influence in photonics logic device

Photonics logic devices are currently finding applications in most of the fields where optical signals are employed. These areas range from optical communications to optical computing, covering as well as other applications in photonics sensing and metrology. Most of the proposed configurations with photonics logic devices are based on semiconductor laser structures with “on/off” behaviors, operating in an optical amplifier configuration. They are able to offer non-linear gain or bistable operation, being these properties the basis for their applications in these fields. Moreover, their large number of potential affecting parameters onto their behavior offers the possibility to choose the best solution for each case

Optical regeneration based on noise generated in bistable devices: going from 2R to 3R

In this paper we propose to employ an instability that occurs in bistable devices as a control signal at the reception stage to generate the clock signal. One of the adopted configurations is composed of two semiconductor optical amplifiers arranged in a cascaded structure. This configuration has an output equivalent to that obtained from Self-Electrooptic Effect Devices (SEEDs), and it can implement the main Boolean functions of two binary inputs. These outputs, obtained from the addition of two binary signals, show a short spike in the transition from "1" to "2" in the internal processing. A similar result is obtained for a simple semiconductor amplifier with bistable behavior. The paper will show how these structures may help recover clock signals in any optical transmission syste

Dispersive optical bistability in quantum wells with logarithmic gain

We present an analytical model for studying optical bistability in semiconductor lasers that exhibit a logarithmic dependence of the optical gain on carrier concentration. Model results are shown for a Fabry–Pérot quantum-well laser and compared with the predictions of a commercial computer-aided design (CAD) software tool

Analysis of Photonic Structures for Optical Networks

Esta Tesis Doctoral describe la física y las aplicaciones de dispositivos biestables de estructuras bulk y pozos cuánticos basados en simulaciones numéricas y computacionales; además se analiza los regeneradores ópticos basados en medidas experimentales. Se desarrolla un modelo numérico para el cálculo de la ganancia óptica en láseres de semiconductor de estructuras tipo bulk y de pozo cuántico para diferentes materiales, posteriormente los datos obtenidos se utilizan en el estudio de la Biestabilidad Óptica Dispersiva en este tipo de estructuras dentro de una cavidad Fabry-Pérot. Se realiza un modelo matemático para el estudio teórico de la Biestabilidad Óptica Dispersiva en Láseres de Pozo cuántico de ganancia logarítmica en una cavidad resonante Fabry-Pérot. Con los resultados obtenidos del modelo matemático realizamos una comparativa con la herramienta de simulación de dispositivos fotónicos llamada VPItransmissionMaker™. Las aplicaciones de la biestabilidad óptica también han sido estudiadas en esta Tesis, tales como, el estudio de la variación del ancho de línea de la señal de entrada a los láseres de semiconductor y cómo afecta dicha variación en la histéresis de la curva biestable del láser semiconductor. Simulación de la Célula Lógica Programable Óptica (Optically Programmable Logic Cell, OPLC) basadas en Láseres de Pozo Cuántico, capaces de proporcionar diferentes funciones lógicas booleanas y se propone teóricamente un circuito de recuperación de la señal de reloj utilizando OPLCs. Finalmente, se realiza un estudio experimental de un regenerador 2R, formado por un amplificador óptico de semiconductor y un electroabsorbedor implementados en la misma guía de onda. Realización de pruebas experimentales en estática y dinámica, comprobación de la capacidad de recuperar la forma de la señal óptica y determinar las mejoras de la relación de extinción y relación señal-ruido. -- Abstract This thesis describes the physics and applications of bistable devices made of bulk and quantum-well structures based on numerical and computational simulations; and analyzes optical regenerators devices based on experimental measurements. A theoretical model of the optical gain in bulk and quantum-well semiconductor structures has been developed to further study the optical bistability in both semiconductor structures within a Fabry-Pérot cavity. An analytical model has been developed for studying dispersive optical bistability in Fabry-Pérot quantum-well semiconductor lasers that exhibit a logarithmic dependence of the optical gain on carrier concentration. The laser is operated in transmission and reflection. Model results are shown for a Fabry-Pérot quantum-well laser and compared with the predictions of a commercial computer-aided design (CAD) software tool named VPItransmissionMaker™. Optical bistability for optical computing applications has also been studied in this thesis. Some of the applications proposed are the linewidth influence in photonics logic devices, where the variation of the linewidth in the optical input signal affects the hysteresis curve of the semiconductor laser. Also, it has been simulated an Optically Programmable Logic Cell based on quantum-well lasers capable to provide boolean logic functions in the optical domain. Additionally, a theoretical study for optical clock recovery using the Optical Programmable Logic Cell (OPLC) has been proposed. Finally, all optical 2R-regeneration based on the integration of semiconductor optical amplifiers and electroabsorbers in a single waveguide is experimentally demonstrated. Static transfer functions of concatenated structures show strong improvements of the nonlinearity. An extinction ratio improvement has been obtained under dynamics operation

La prueba de oficio en el proceso civil en Colombia /

71 hojas ; 28 cmPregradoAbogadoTrabajo de grado (Abogado) -- Corporación Universitaria del Caribe. Facultad de Derecho y Ciencias Políticas. Programa de Derecho, Sincelejo 2012

Activation of Snap-Top Capped Mesoporous Silica Nanocontainers Using Two Near-Infrared Photons

Photoactivation of “snap-top” stoppers over the pore openings of mesoporous silica nanoparticles releases intact cargo molecules from the pores. The on-command release can be stimulated by either one UV photon or two coherent near-IR photons. Two-photon activation is particularly desirable for use in biological systems because it enables good tissue penetration and precise spatial control. Stoppers were assembled by first binding photolabile coumarin-based molecules to the nanoparticle surface. Then, after loading the particles with cargo, bulky β-cyclodextrin molecules were noncovalently associated with the substituted coumarin molecule, blocking the pores and preventing the cargo from escaping. One-photon excitation at 376 nm or two-photon excitation at 800 nm cleaves the bond holding the coumarin to the nanopore, releasing both the cyclodextrin cap and the cargo. The dynamics of both the cleavage of the cap and the cargo release was monitored using fluorescence spectroscopy. This system traps intact cargo molecules without the necessity of chemical modification, releases them with tissue penetrating near-IR light and have possible applications in photo-stimulated drug delivery