Light-induced self-writing effects in bulk chalcogenide glass

A waveguide can be self-written by a beam of light propagating in a photosensitive material. We report the first observation of self-writing effects in bulk chalcogenide glass and investigate the influences of different writing beam sizes and powers. We observe increases in refractive index of 2.5×10^-4 due to illumination at 1047 nm in Ce-doped Ga-La-S. Simulations of the self-writing process show a good agreement with the experimental results. This verifies our numerical model and allows the dynamics of this process to be explored. Using this knowledge, we predict the experimental parameters and conditions required to write waveguides, tapers, and ultimately complex three-dimensional (3-D) structures