Highly germanium and lanthanum modified silica based glasses in microstructured optical fibers for nonlinear applications

• Published in: Optical materials Vol. 32; no. 9; pp. 1002 - 1006
• Main Authors: Kobelke, Jens, Schuster, Kay, Litzkendorf, Doris, Schwuchow, Anka, Kirchhof, Johannes, Tombelaine, Vincent, Bartelt, Hartmut, Leproux, Philippe, Couderc, Vincent, Labruyère, Alexis, Jamier, Raphaël
• Format: Journal Article
• Language: English
• Published: Elsevier 2010
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2010.02.019

Modified core glass materials in silica-clad microstructured fibers (MOFs) promise efficient conversion of non-linear processes, e.g. for supercontinuum (SC) generation. We used extremely highly germanium-doped silica (max. 36 mol% GeO2) and lanthanum aluminum silicate glasses with high lanthanum oxide concentration (max. 10 mol% La2O3) as core materials. The microstructured optical fibers (Ge-MOFs, La-MOFs) were prepared in five air ring architecture by a stack-and-draw technique using silica for the cladding region. The MOFs show loss minima of about 0.05 dB m−1 (Ge-MOF) and 1.3 dB m−1 (La-MOF) at a wavelength of 1.064 μm. Such Ge-MOFs and La-MOFs are compatible with conventional silica fibers giving low loss splices with standard single mode fibers. The non-linearity of the La-MOF is approximately two times higher than that of the Ge-MOF, but shows a significantly higher spectral loss. Ge-MOF and La-MOF can both produce similar ultra-broad band supercontinuum spectra from VIS (540 nm and 500 nm) to IR range (2400 nm and 2220 nm) by being pumped with a passively Q-switched Nd:YAG microchip laser.