Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 56: Ultrakurze Laserpulse: Anwendungen 3
Q 56.1: Vortrag
Donnerstag, 17. März 2011, 14:30–14:45, SCH A215
Role of Ferroelectric Domain Distribution and Shape in Čerenkov Second Harmonic Generation — •Philip Roedig, Mousa Ayoub, Jörg Imbrock, and Cornelia Denz — Institut für Angewandte Physik and Center for Nonlinear Science (CeNoS), Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
Nonlinear parametric processes are known to depend critically on phase matching between the phase velocities of the interacting waves. Phase matching is mostly achieved by using conventional methods like crystal birefringence or quasi-phase matching (QPM) techniques.
Recently, it was pointed out that unpoled ferroelectric crystals can also be used for frequency conversion in nonlinear optics being considered as randomly structured domain media that allow e.g. for tunable phase-matched second-harmonic generation (SHG) practically in the whole transparency range of the crystal. Two characteristic emission configurations, namely planar and Čerenkov geometries, were suggested.
In this contribution, we systematically study the characteristics of Čerenkov second-harmonic generation in multi-domain χ2 strontium barium niobate crystals by femtosecond laser pulses. Starting from an unpoled sample having a random domain distribution, different degrees of disorder are experimentally generated, offering a possibility to achieve deformation in the shape and distribution of the ferroelectric domains. This results in an enhancement of the efficiency conversion of such type of second harmonic generation and features remarkable modulations in the SH intensity emission patterns.