Large photoinduced refractive index changes in pulsed-laser-deposited lead germanate glass waveguides with controllable refractive index sign change

Photosensitive lead germanate glass optical waveguides have been grown by pulsed laser deposition. The deposited waveguides are photosensitive over a broad ultraviolet spectral range (325-193 nm). Positive and/or negative refractive index changes have been observed, depending on the intensity of the ultraviolet radiation as well as on the deposition conditions. Absolute refractive index change values up to |(n|=1.06᎒^-2 have been measured.