Advanced Photonics Research (Jun 2021)

Second‐Order Optical Response in Electrically Polarized Sodo‐Niobate Amorphous Thin Films: Particularity of Multilayer Systems

  • Lara Karam,
  • Frédéric Adamietz,
  • Dominique Michau,
  • Ganapathy Senthil Murugan,
  • Thierry Cardinal,
  • Evelyne Fargin,
  • Vincent Rodriguez,
  • Kathleen A. Richardson,
  • Marc Dussauze

DOI
https://doi.org/10.1002/adpr.202000171
Journal volume & issue
Vol. 2, no. 6
pp. n/a – n/a

Abstract

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Herein, our attention is focused on the second‐order optical properties of thermally poled sodo‐niobate amorphous thin films through an original methodology that combines both macroscopic and microscopic second harmonic generation techniques. By probing the geometry and the magnitude of the second‐order nonlinear (SONL) optical response at different scales, a key aspect of thin film's poling mechanisms compared with bulk glasses is demonstrated that lies in the appearance of a charge accumulation at the film/substrate interface and that is described by the Maxwell–Wagner effect. A way to minimize this effect is then proven by promoting an induced built‐in static field in the plane of the film using a microstructured electrode. A SONL optical susceptibility as high as 29 pm V−1 is measured and its geometry and location are controlled at the micrometer scale; it constitutes an improvement of at least one order of magnitude compared with other poled amorphous inorganic materials and is comparable with that of lithium niobate single crystal.

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