A. A. Rybaltovsky

Fabrication of fiber Bragg gratings with 267 nm femtosecond radiation

Strong high-quality fiber Bragg gratings with photoinduced refractive-index modulation of more than 10-(3) were written in a Corning SMF-28 fiber, a P(2)O5-doped-core fiber and a pure-silica-core fluorine-doped-cladding fiber by third-harmonic radiation (267 nm, 150 fs and 1.2-1.8x1011 W/cm(2)) of a femtosecond Ti:sapphire laser using a phase mask. We compare the 267-nm photosensitivity responses with the results of irradiation by 193-nm ArF and 157-nm F(2) excimer lasers. The dependence of the refractive-index change on the exposure dose and the annealing characteristics of the fabricated gratings are typical for Type-I UV-written fiber gratings.

Influence of hydrogen loading and UV irradiation on optical properties of phosphorus-doped fibers

Optical loss in a hydrogen-loaded phosphorus-doped fiber treated with a 193 nm ArF eximer laser light was studied. It follows from the experiments that additional optical losses in the region of 1.0-1.6 µn must remain negligible after writing a Bragg grating. Absorption spectra of the phosphorus-doped fiber after hydrogen loading and UV-irradiation differ strongly from that of a germanium-doped fiber.

Photosensitivity and induced losses in phosphosilicate fibers exposed to 157 and 193 nm irradiation

Photosensitivity and induced losses in phosphosilicate fibers depend on irradiation wavelength. The best induced index/loss relation has been obtained for H2-loaded samples at 157 nm irradiation. Pre-exposure procedure failed to decrease the induced losses.

High photosensitivity of Al2O3-doped fibers to 193 nm and 157 nm excimer laser irradiation

Significant photosensitivity of aluminosilicate fibers (with and without Er codoping) was observed. Effect of photosensitization was demonstrated for the first time for such fibers. Potential to write gratings directly in Er-doped aluminosilicate fibers was demonstrated.