Optical component coupling using self-written waveguides

The self-written waveguide is a possible solution to improving the alignment of optical connections. By introducing light from an optical fibre edge to a photosensitive medium, an optical waveguide easily forms under the condition that the refractive index of the exposed medium increases; it gives a hybrid optical component composed of an optical fibre and an optical waveguide without any alignment adjustment. The method is described and experimental results given for multi-mode fibre (MMF) coupling. Self-written waveguides were successfully formed in the gap between two MMFs; the coupling loss was about 0.6 dB for a 500 μm gap.