Programa del congreso

For the generation of optical propagation modes using a phase-only spatial light modulators, it is essential that both phase and amplitude components of their complex amplitude fields are encoded. In this paper, we obtain the complete expression of the complex field generated at Fresnel and Fraunhofer distances when applying a simple technique consisting of the use of checkerboard-type holograms to encode both phase and amplitude information. The obtained expression is verified with a developed simulator that calculates the complex field generated at any propagation distance by applying the Huygens-Fresnel principle. The simulation results corroborate that the desired mode propagates in even diffraction orders, even in near field.

Este trabajo presenta un modelo de canal óptico inalámbrico submarino, orientado específicamente a enlaces con configuración de sin linea de visión directa (NLOS), considerando la presencia de una superficie marina ondulante. Nuestro modelo de canal ofrece un análisis exhaustivo y determinista del impacto de las olas del mar, permitiendo determinar de manera precisa el tamaño variable del haz óptico reflejado en el plano del receptor por la superficie marina. Los resultados obtenidos confirman que la variablidad de las olas oceánicas induce desalineaciones severas en el enlace óptico, creando oportunidades intermitentes para la comunicación efectiva. El análisis óptico-geométrico contribuye significativamente de una forma novedosa al impacto de la olas oceánicas en sistemas NLOS-UOWC. Estos resultados pueden mejorar las consideraciones preliminares en el diseño de enlaces NLOS, especialmente en escenarios donde los vehículos submarinos autónomos están en constante movimiento, contribuyendo a la reducción de errores de apuntamiento.

The significant growth of free-space optic communications and Light Detection and Ranging (LiDAR) is demanding gratings that emit highly collimated beams, i.e. with Rayleigh ranges of millimeters or even centimeters. Hence, weak-strength gratings, which radiate little amount of power per unit length, are needed. The main purpose of this work is to propose an efficient and accurate simulation tool to accelerate the design of weak-strength gratings required for these applications. To achieve this, we propose a simulator based on the classical perturbation method, which takes a circuit approach to the electromagnetic problem. Comparison with results obtained with a rigorous 2D full wave electromagnetic simulator (FEXEN) shows very good agreement with the advantage of decreasing simulation times by up to a factor x16.

In this work we develop add-drop filters based on Mach-Zehnder interferometers whose arms have been loaded with a pair of identical Bragg gratings. We later addressed their multiband capacity and performance on the commercial silicon-on-insulator platform. 1-band, 2-band and 4-band add-drop filters were compliant with the LAN-WDM standard, fit to a wavelength grid of 4.5-nm spaced and 3-nm wide channels. Experimental measurements show a gradual degradation with increasing number of channels, while working devices had an insertion loss below 1 dB and a crosstalk of about -18 dB. We believe these results pave the way for further development of Bragg grating based add-drop filters on the lower index contrast silicon nitride platform.