Ultrafast laser plasma doping of Er^3+ ions in silica-on-silicon for optical waveguiding applications

Abstract

An ultrafast laser plasma doping (ULPD) technique is used to high concentration doping of erbium ions into silica-onsilicon substrate. The method uses femtosecond laser to ablate material from TeO2-ZnO-Na2O-Er2O3 (Er-TZN) target glass. The generated plasma modifies the silica network, producing high index contrast optical layer suited to the production of on-chip integrated optical circuits. Cross-sectional analysis using scanning electron microscope with energy dispersive x-ray spectroscopy revealed homogenous intermixing of the host silica with Er-TZN, which is unique to ULPD. The highly doped layer exhibits spectroscopic characteristics of erbium with photoluminescence lifetimes ranging from 10.79 ms to 14.07 ms.

Effect of Substrate Temperature on Morphological, Structural, and Optical Properties of Doped Layer on SiO2-on-Silicon and Si3N4-on-Silicon Substrate

“…The selection of the material host for EDWA is crucial as it affects the gain per unit length, which is closely related to the solubility of the dopant Er and its photoluminescence lifetime [ 12 ]. Silica-based waveguides have the potential to provide the best characteristics of a host to Er in EDWAs because of their refractive index matching with well-established silica optical fibre that potentially minimises coupling loss [ 13 ]. Apart from silica, silicon nitride (Si 3 N 4 ) is seen as a potential host material for EDWA applications.…”

“…Ultrafast laser plasma doping (ULPD) is a technique that has been proven successful for doped Er 3+ -ions in relatively high concentrations without the occurrence of severe clustering issues in silica-based film, and the obtained layer is referred to as Er-doped tellurite-modified silica (EDTS) [ 13 , 15 , 16 ]. In this approach, the target glass is ablated using a femtosecond laser.…”

“…The surface implantation and dissolution of ions and nanoparticles produced by the femtosecond laser-induced plasma into the substrate surface network results in the structural modification of the substrate surface [ 17 ]. Previous studies have proven Er-TZN to be successfully doped into silica [ 13 , 15 , 16 , 18 , 19 , 20 ]. Since this process is also assisted by substrate heating during the doping process, selecting the appropriate temperature is very critical.…”

Femtosecond laser ablation properties of Er3+ ion doped zinc-sodium tellurite glass

“…12 This technique has also been proven for silica-on-silicon (SOS) substrates, which is particularly promising as it enables the use of technology developed for microelectronics. 13 In brief, ULPD forms thin films onto a substrate by ablating an Er 3þ ion doped zinc-sodium tellurite (TZN) glass with femtosecond laser irradiation. The plume resulting from the ablated volume reacts with a substrate forming a superficial rare earth doped tellurite modified silica layer.…”

Thickness Study of Er-Doped Magnesium Zinc Oxide Diode by Spray Pyrolysis

“…Rare-earth-doped materials have been widely investigated in many applications in past decades [1][2][3][4][5]. Erbium (Er), one of the rare earth materials, has shown good performance in optoelectronic devices [6][7][8].…”