Electric field induced structural modification and second order optical nonlinearity in potassium niobium silicate glass
2009 (English)In: Journal of Non-Crystalline Solids, ISSN 0022-3093, E-ISSN 1873-4812, Vol. 355, no 52-54, 2578-2582 p.Article in journal (Refereed) Published
Second harmonic generation properties have been studied in 23 K2O center dot 27Nb(2)O(5) center dot 50 SiO2 glass subjected to thermal poling. The poling-induced optical nonlinearity. with chi((2)) = 3.8 pm/V, has been related to structural modifications within a surface layer of a few microns on the anode side, as evidenced by means of confocal micro-Raman mapping along the sample thickness. The data indicate that the structural changes result from a charge transport process that causes network modifications in an alkali depleted layer whose thickness is comparable with that of the non-linear region. The Raman data also indicate that in the alkali depleted layer the network polymerization degree increases as a consequence of ion migration. The origin of the nonlinearity and the mechanisms activated by poling are discussed. The mechanism of non-bridging-oxygen to bridging-oxygen bond switching is proposed to explain ion migration and the subsequent structural changes in the glass.
Place, publisher, year, edition, pages
2009. Vol. 355, no 52-54, 2578-2582 p.
Non-linear optics, Raman spectroscopy, Silicates, Poling, ionic-transport-properties, 2nd-harmonic generation, borophosphate, glasses, atomic-structure, blocking anode, oxide glasses, surface, sodium, irradiation, depletion
IdentifiersURN: urn:nbn:se:kth:diva-19048DOI: 10.1016/j.jnoncrysol.2009.09.005ISI: 000272760700009ScopusID: 2-s2.0-71849118814OAI: oai:DiVA.org:kth-19048DiVA: diva2:337095
QC 201005252010-08-052010-08-052011-02-04Bibliographically approved