Fabrication of erbium-doped planar waveguides by pulsed-laser deposition and laser micromachining

Abstract

Laser radiation is used both for the deposition of dielectric Er:BaTiO₃ thin films and for material removal to generate wave guiding structures for photonic applications. Pulsed laser deposition with KrF excimer laser radiation (wavelength 248 nm, pulsed duration 20 ns) is used to grow dense, transparent amorphous or crystalline erbium doped BaTiO₃ thin films. Visible emission due to up-conversion luminescence (wavelength 528 nm and 548 nm) under excitation with diode laser radiation at a wavelength of 975 nm is investigated as a function of the erbium concentration and structural film properties. The dielectric films are micro machined to form optical wave guiding structures using Nd:YAG laser radiation (wavelength 532 nm, pulsed duration 40 ps) and Ti:sapphire laser radiation (wavelength 810 nm, pulse duration 63 - 150 fs) by scanning the focused laser beam relatively to the sample.