Temporal self-imaging effect for periodically modulated trains of pulses

In this paper, the mathematical description of the temporal selfimaging effect is studied, focusing on the situation in which the train of pulses to be dispersed has been previously periodically modulated in phase and amplitude. It is demonstrated that, for each input pulse and for some specific values of the chromatic dispersion, a subtrain of optical pulses is generated whose envelope is determined by the Discrete Fourier Transform of the modulating coefficients. The mathematical results are confirmed by simulations of various examples and some limits on the realization of the theory are commented

Línea de retardo sintonizable eléctricamente para trenes de pulsos ópticos basada en el efecto de autoimagen temporal

En este artículo se presenta una nueva técnica para la realización de una línea de retardo para trenes de pulsos ópticos ultracortos basada en dispositivos habituales en enlaces de fibra óptica. El sistema está basado en la introducción, mediante un modulador electro?óptico, de una fase lineal a un tren de pulsos de entrada para su posterior dispersión consiguiéndose el efecto de autoimagen temporal en fibra. La sintonía eléctrica del retardo introducido se consigue mediante la variación de la pendiente de la señal eléctrica aplicada en el modulador, obteniéndose una sintonía continua a lo largo de todo el periodo de la señal. Dada la imposibilidad práctica de realizar un generador lineal cuya salida no esté limitada en el tiempo, se propone el uso de una señal rampa, reduciéndose por tanto el rango de sintonía a un conjunto de valores discretos para evitar la deformación del tren de pulsos a la salida del sistema. Resultados obtenidos por simulación prueban la validez del esquema propuesto

Optical signal processing with electrooptic modulators and dispersion

A review of the main techniques that have been proposed for temporal processing of optical pulses that are the counterpart of the well-known spatial arrangements will be presented. They are translated to the temporal domain via the space-time duality and implemented with electrooptical phase and amplitude modulators and dispersive devices. We will introduce new variations of the conventional approaches and we will focus on their application to optical communications system

Periodic time-domain modulation for the electrically tunable control of optical pulse train envelope and repetition rate multiplication

An electrically tunable system for the control of optical pulse sequences is proposed and demonstrated. It is based on the use of an electrooptic modulator for periodic phase modulation followed by a dispersive device to obtain the temporal Talbot effect. The proposed configuration allows for repetition rate multiplication with different multiplication factors and with the simultaneous control of the pulse train envelope by simply changing the electrical signal driving the modulator. Simulated and experimental results for an input optical pulse train of 10 GHz are shown for different multiplication factors and envelope shapes

Validación experimental de una línea de retardo para trenes de pulsos ópticos reconfigurable eléctricamente

En este trabajo se verifica experimentalmente la sintonía del retardo para un tren de pulsos ópticos ultracortos mediante el uso de tan solo un modulador de fase y un elemento dispersivo cuya dispersión viene fijada por la frecuencia del tren de pulsos de entrada. La sintonía del retardo se realiza mediante la variación de una señal eléctrica periódica cuya velocidad de repetición es similar a la del tren de entrada. Los resultados obtenidos demuestran la posibilidad de obtener valores de retardos arbitrarios dentro de un periodo de repetición y sin distorsión de la forma de los pulsos a la salida del sistema

Characterization of microring filters for differential group delay applications

The longitudinal offset technique permits to improve the accuracy of the coupling coefficients of integrated directional couplers and provides designs that can be easily implemented with current fabrication tolerances. In this work, we address the additional degree of freedom offered by this technology in order to tailor the differential group delay in coupled-resonator optical filters. We present the characterization of several devices exploiting this feature and we discuss their potential applicationsThis work has been founded by MINECO (Spanish Government), project numbers TEC2010-21303-C01, 02, 03 and 04, and JCyL Project No. VA089U16. F. J. F.-P. has also been partly supported by the ERDF and by the Galician Regional Government under project GRC2015/018 and under agreement for funding AtlantTI

Conceptualization and Realization of a Framework for Model-Based, Automatic User Interface Generation

The Personal Environment Controller (PECo) is a digital assistant system that provides the user with a unified facility for organizing as well as accessing the different media repositories at his disposal and direct manipulation of the physical environment (projectors, TV sets, hi-fi systems, Lights, shutters, etc.). To interact with the environment, PECo´s user interface is based on the 3D visualization of the room, allowing the user the intuitive selection of a device, basing his selection on the device position and orientation within the 3D model of the room. The main purpose of this thesis is the development and implementation of a system that can dynamically update this user interface, providing PECo with a model that describes the environment. It will be based on the UPnP architecture and the Ubisense system. UPnP allows us to perform the discovery and control of the available devices. Ubisense is a commercial indoor location system. They will inform us of the changes in the environment through some events that our system will receive and process to automatically generate the 3D user interface model. The main application area are for PECo is AmI meeting rooms. Unfortunately, UPnP is oriented to the house automation. Consequently, a generic UPnP Presentation Architecture for AmI meeting rooms has been developped. This architecture introduces besides standard lighting devices also a UPnP design for complex projection settings, analog audio-video devices, shutter blinds and media repositories. Using this architecture, AmI developers benefit form UPnP device discovery as well as standardized access to devices and media repositories