Sistemas de focalización óptica para comunicaciones ópticas de espacio libre (FSO)

Abstract

[ES] El trabajo tiene como objetivo el estudio y diseño de los elementos de focalización ópticos necesarios para el desarrollo de enlaces ópticos inalámbricos en el espectro visible mediante el uso de láseres y LEDs. Se estudiará el acoplo entre la fuente óptica y el aire, la fibra óptica de polímero y desde la fibra o aire al detector, teniendo en cuenta enlaces ópticos de característica dispersa o focalizada. El estudio se adaptará a las características de componentes comerciales de manera que los resultados obtenidos en este trabajo se utilizarán en los montajes experimentales de una futura tesis doctoral enmarcada en el proyecto de investigación FOCAL.

[EN] Visible light communication technology (VLC) is emerging as an alternative to RF communications especially for wireless communications in indoor environments. VLC is an emerging technology that uses light in the spectrum from 380nm to 750nm instead of radio frequency signals for data transmission. The use of imaging lenses as collimators and optical antennas to improve the SNR in VLC systems is analyzed using LD's and LED's as optical sources. Firstly, a design of spherical lens is proposed to collimate a light source of gaussian angular distribution using geometric methods. At the same time, ZEMAX commercial simulator is used both for the validation of the geometric fundamentals and to extend the results and the analysis that could be limited if only geometric optics were used. The use of aspherical lenses is also proposed to improve the performance of the VLC system. The results show that the use of aspherical lenses as a collimating lens reduces the divergence angles of the beam improving collimation distances. Finally, the advantages and disadvantages of different commercial lenses on non-directed LOS and directed LOS links using an LED as an optical source are described.