Visible laser self-focusing in hybrid glass planar waveguides.

We report that self-focusing occurs with simultaneous self-inscription of a cylindrical waveguide when 514.5-nm light from a cw argon-ion laser propagates in a solgel-derived silica methacrylate hybrid glass planar waveguide. Spatially localized free-radical polymerization of methacrylate substituents is initiated in the path of the guided wave. This causes intensity-dependent refractive-index changes that lead to self-lensing and focusing. A channel waveguide evolves in the matrix, which supports fundamental and higher-order optical modes and suppresses diffraction of the beam.