Nelson D. Gómez-Cardona

Temperature sensibility of the birefringence properties in side-hole photonic crystal fiber filled with Indium

We report on the temperature sensitivity of the birefringence properties of a special kind of photonic crystal fiber containing two side holes filled with Indium metal. The modulation of the fiber birefringence is accomplished through the stress field induced by the expansion of the metal. Although the fiber was made at low gas pressures during the indium infiltration process, the birefringence showed anomalous property at a relatively low temperature value, which is completely different from those reported in conventional-like fibers with two holes filled with metal. By modeling the anisotropic changes induced by the metal expansion to the refractive index within the fiber, we are able to reproduce the experimental results. Our results have practical relevance for the design of devices based on this technology.

Compensación de Dispersión Cromática Usando Fibras de Cristal Fotónico con Distribución Hexagonal

In this paper we show various configurations of photonic crystal fiber with hexagonal holes distribution for compensation of chromatic dispersion in optical communications links. The vectorial finite element method with scattering boundary condition was used for the analysis of the fibers. From these results it was estimated variation of the dispersion and the dispersion slope with respect to change in the diameter of the holes in the microstructure. With the above was possible to obtain values of dispersion in the C and L bands of telecommunications close to -850 ps / nm * km, with confinement losses 10-3 dB / kmIn this paper we show various configurations of photonic crystal fiber with hexagonal holes distribution for compensation of chromatic dispersion in optical communications links. The vectorial finite element method with scattering boundary condition was used for the analysis of the fibers. From these results it was estimated variation of the dispersion and the dispersion slope with respect to change in the diameter of the holes in the microstructure. With the above was possible to obtain values of dispersion in the C and L bands of telecommunications close to -850 ps / nm * km, with confinement losses 10-3 dB / km

Análisis de la Transmisión de Tramas STM-N sobre un Enlace de Fibra Óptica DWDM

In this work, we present an analysis of physical layer performance of a DWDM-link of 66 km of single-mode optical fiber on which is implemented a SDH system to send STM-1 at 155 Mbps. We show the computational simulation in Optisystem 7.0 (Evaluation Version) to analyze the DWDM system characteristic at 2.5 Gbps equivalent to a STM-16 frame. The results of the eye diagram and BER show that is possible to distinguish between bits when the detector thermal-noise is less than 1x10-19 W/Hz. We analyze experimental measurements of jitter and its corresponding comparison with the value normalized by the ITU-T for a STM-1 frame. The use of more wavelengths is proposed to maximize the transmission capacity of fiber optics or installation of interfaces with high capacity for increasing the available bandwidth.

Diseño y Construcción de una Red de Fibra Óptica para Análisis de Topologías y Transmisión de Señales en Dispositivos para Redes WDM- PON

In this work, we designed and built a fiber optic-network in the optical laboratory of the Instituto Tecnologico Metropolitano.This network was used to emulate different topologies almost real conditions with the possibility to make connections up to 45 km. We present experimental results of analysis in different network scenarios. Furthermore, we present experimental results for signal transmission and the transmission of four simultaneous channels by using an optics-multiplexor. Successful detection after 12 and 32 km through and passive optical network by wavelength division multiplexing is demonstrated. Finally, we present power and loss measures in terminals with a star topology and results for pulse transmission from Optical Reflectometer in the time domine. As far as we know, this is the first report and application in Colombia of a technological development of a laboratory network for topology analysis. This laboratory network will allow future applications like sensors testing and optical routing.

Magnetomechanically induced long period fiber gratings

In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs.

In‐fiber Integrated Micro‐displacement Sensor

In this paper, a compact in‐fiber integrated micro‐displacement sensor, based on a two‐core fiber in a loop configuration, is outlined. It consists of a segment of two‐core fiber fused with standard single‐mode fiber, and a dielectric mirror directly deposited on the end face of the two‐core fiber. Then, when the two‐core fiber is directly powered by an optical source through a 3dB coupler, the reflected signals from the mirrored end of the two‐core fiber are combined in the fused zone and received by a photo detector. In this way, a practical Michelson interferometer can be implemented. The basic idea behind our approach is to use the optical path change induced in the two‐core fiber loop, where the axis joining the cores is parallel to the loop plane, when the loop is deformed and leading differential phase retardation between the two cores. We have found that the behavior of the sensor is linear and its sensitivity can be adjusted.