| Autor: |
H, Brüning, V, Dieckmann, B, Schoke, K-M, Voit, M, Imlau, G, Corradi, C, Merschjann |
| Rok vydání: |
2012 |
| Zdroj: |
Optics express. 20(12) |
| ISSN: |
1094-4087 |
| Popis: |
Diffraction efficiency, relaxation behavior and dependence on pump-beam intensity of small-polaron based holograms are studied in thermally reduced, nominally undoped lithium niobate in the visible spectrum (λ = 488 nm). The pronounced phase gratings with diffraction efficiency up to η = (10.8 ± 1.0)% appeared upon irradiation by single ns-laser pulses (λ = 532 nm) and are comprehensively assigned to the optical formation of spatially modulated densities of small bound NbLi4+ electron polarons, NbLi4+:NbNb4+ electron bipolarons, and O⁻ hole polarons. A remarkable quadratic dependence on the pump-beam intensity is discovered for the recording configuration K || c-axis and can be explained by the electro-optic contribution of the optically generated small bound polarons. We discuss the build-up of local space-charge fields via small-polaron based bulk photovoltaic currents. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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