Preparation and characterization of sol-gel derived Er3+: Al2O3-SiO2 planar waveguides

Abstract

Er 3+ doped aluminosilicate thin films were prepared on silica and silica Si substrates by the sol-gel method. The Er ion concentration was varied from 0.25% to 1%. Fluorescences of Er ions in the visible and infrared regions were characterized. Green and red up-conversion fluorescences centered at 548 and 655 nm for, respectively, the (2H11/2+4S3/2)→4I15/2 and 2F9/2→4I15/2 were observed. A broadband peak was observed at 1531 nm corresponding to the 4I13/2 → 4I15/2 transition, with the full width at half-maximum of 47 nm comparable to those prepared by other methods. The fluorescence lifetime of the 4I13/2 excited state was found to be constant and equal to 3.5 ms until a high Er doping of 0.5 at. %.

Sol-gel silica-on-silicon buried-channel EDWAs

“…However, crystallization has been observed with Al O at high annealing temperatures [79]. Low process temperatures have also been shown to be important to preserve luminescence lifetime [86].…”

“…Initial investigations were performed on Nd-doped glasses [72], [73], but attention is now concentrated on Er doping, using hosts ranging from pure SiO [74] to TiO -SiO [75]- [78], Al O -SiO [79], [80], P O -SiO [81], Al O -TiO -SiO [82], and GeO -SiO , with both weak [83] and high [84] germania contents.…”

Sol-gel Technology for Sensor Applications

“…Sol-gel-processed materials have been used in the area of solid-state lasers 66,67 . The sol-gel method also provides a convenient route to prepare luminescent glass optical fibres doped with rare earth ions 68,69 , waveguides 70,71 , and lasers 72 . The sol-gel technique has also been used to fabricate nonlinear, optically active composites for applications in optical telecommunications 73 .…”

AI2O3:Er3+ as a gain platform for integrated optics

“…For devices based on rare-earth-ion transitions OH --free deposition is required, because these bonds induce strong luminescence quenching and, hence, greatly diminish or prohibit optical gain. When comparing the properties of previously applied deposition techniques, it becomes obvious that CVD and sol-gel techniques inherently suffer from OH -incorporation [36,83,84,86] due to the presence of hydrogen in the process precursors. The application of ALD for optical waveguides, although resulting in thin films with excellent quality, is limited due to its very low deposition rate, which typically results in film thicknesses of only up to several tens of nanometers.…”

“…During the past decades a number of research groups have investigated and developed Al 2 O 3 deposition processes based on different techniques: pulsed laser deposition (PLD) [79,80], atomic layer deposition (ALD) [81,82], chemical vapour deposition (CVD) [36,[83][84][85], the sol-gel method [80,86,87], sputtering from a dielectric target [75,88], and reactive co-sputtering based on a metallic target [37,89,90].…”