Electro-Optic Control of Lithium Niobate Bulk Whispering Gallery Resonators: Analysis of the Distribution of Externally Applied Electric Fields

Crystals

Hans Zappe¹  Yannick Minet²  Karsten Buse²  Ingo Breunig² 

[1] Gisela and Erwin Sick Chair of Micro-Optics, Department for Microsystems Engineering—IMTEK, University of Freiburg, Georges-Köhler-Allee 102, 79110 Freiburg, Germany;Laboratory for Optical Systems, Department for Microsystems Engineering—IMTEK, University of Freiburg, Georges-Köhler-Allee 102, 79110 Freiburg, Germany;

关键词: electro-optics;    whispering gallery resonators;    lithium niobate;   

DOI  :  10.3390/cryst11030298

来源: DOAJ

【 摘 要 】

Whispering gallery resonators made out of lithium niobate allow for optical parametric oscillation and frequency comb generation employing the outstanding second-order nonlinear-optical properties of this material. An important knob to tune and control these processes is, e.g., the linear electro-optic effect, the Pockels effect via externally applied electric fields. Due to the shape of the resonators a precise prediction of the electric field strength that affects the optical mode is non-trivial. Here, we study the average strength of the electric field in z-direction in the region of the optical mode for different configurations and geometries of lithium niobate whispering gallery resonators with the help of the finite element method. We find that in some configurations almost 100% is present in the cavity compared to the ideal case of a cylindrical resonator. Even in the case of a few-mode resonator with a very thin rim we find a strength of 90%. Our results give useful design considerations for future arrangements that may benefit from the strong electro-optic effect in bulk whispering gallery resonators made out of lithium niobate.

【 授权许可】

Unknown