Self-written channels in ion-exchanged waveguides; experiment and modelling of photosensitivity

Summary form only given. We report on the first observations of photosensitivity in potassium ion-exchanged Nd-doped (1.5 wt%) Bk7 borosilicate glass, and create self-written channel waveguides in this material. An argon-ion Gaussian laser beam at 457 nm is focused down to a FWHM of 7 /spl mu/m at the input face of a 14 mm long planar waveguide formed by a 2 /spl mu/m deep ion-exchanged layer. To investigate the photosensitivity in this material, we explore how the initial speed of the waveguide evolution depends on the writing power (for a given beam width).