Identification of Nanocrystalline Inclusions in Bismuth-Doped Silica Fibers and Preforms

Liudmila D Iskhakova; Filipp O Milovich; Valery M Mashinsky; Alexander S Zlenko; Sergey E Borisovsky; Evgeny M Dianov

doi:10.1017/S1431927616011569

Identification of Nanocrystalline Inclusions in Bismuth-Doped Silica Fibers and Preforms

Microsc Microanal. 2016 Oct;22(5):987-996. doi: 10.1017/S1431927616011569. Epub 2016 Sep 26.

Authors

Liudmila D Iskhakova¹, Filipp O Milovich¹, Valery M Mashinsky¹, Alexander S Zlenko¹, Sergey E Borisovsky², Evgeny M Dianov¹

Affiliations

¹ 1Fiber Optics Research Center,Russian Academy of Sciences,38 Vavilov Street,119333 Moscow,Russia.
² 3Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry,Russian Academy of Sciences,35 Staromonetniy per.,119027 Moscow,Russia.

PMID: 27665930
DOI: 10.1017/S1431927616011569

Abstract

The nature of nanocrystalline inclusions and dopant distribution in bismuth-doped silicate fibers and preforms are studied by scanning and transmission electron microscopy, and energy and wavelength-dispersive X-ray microanalysis. The core compositions are Bi:SiO2, Bi:Al2O3-SiO2, Bi:GeO2-SiO2, Bi:Al2O3-GeO2-SiO2, and Bi:P2O5-Al2O3-GeO2-SiO2. Nanocrystals of metallic Bi, Bi2O3, SiO2, GeO2, and Bi4(GeO4)3 are observed in these glasses. These inclusions can be the reason for the background optical loss in bismuth-doped optical fibers. The bismuth concentration of 0.0048±0.0006 at% is directly measured in aluminosilicate optical fibers with effective laser generation (slope efficiency of 27% at room temperature).

Keywords: bismuth; microprobe analysis; nanocrystalline inclusions; optical fiber; transmission electron microscopy.