Optically-induced growth of fiber patterns into a photopolymerizable resin

We present evidence of optically-induced growth of fiber patterns into a photopolymerizable resin. Optical growth of a single or multiple fibers is achieved by focusing an ultraviolet (UV)-laser light into the photopolymerizable resin used. The fiber growth is due to an effect in which photopolymerization of the resin upon light irradiation produces an increase of the resin refractive index, the change of which, in turn, confines the light propagation into waveguide-type fiber structures. We have also observed that two optically grown independent fibers can merge to form a single fiber under specific conditions. We have studied the dependence of this optical growth of fiber structures phenomena on all the experimental parameters, including the numerical aperture (NA) of the lens used to focus the light, the light power, and the exposure time. (C) 1999 American Institute of Physics. [S0003-6951(99)01131-6].