Characterization of UV written waveguides with luminescence microscopy.

Luminescence microscopy is used to measure the refractive index profile and molecular defect distribution of UV written waveguides with a spatial resolution of ~0.4 ?m and high signal-to-noise ratio. The measurements reveal complex waveguide formation dynamics with significant topological changes in the core profile. In addition, it is observed that the waveguide formation process requires several milliseconds of UV exposure before starting.