Abstract

When a drop of photosensitive monomer is deposited on top of a cleaved fiber end, the light coming from the fiber can be self-focused if the polymer refraction index is higher that that of the monomer. The ensuing polymerization along the path of the beam shapes a micrometric size polymer tip that is firmly attached to the fiber end. The applications of this waveguiding component are numerous and range from simply enlarging the numerical aperture of the fiber to improving laser diode coupling performances and near field imaging. Those interests are magnified by its very low price and easy manufacturing. This paper is devoted to modelling the buildup process of this component through time-resolved photopolymerisation in order to evidence the experimental parameters that most influence the tip shape and thus its optical functions. A computational series based on experimental results using a standard Beam Propagation Method (BPM) scheme results in showing the critical influence of the growing atmosphere upon the hemispherical shape of the tip.

© 2003 Optical Society of America