Piezoelectric Resonance Enhanced Microwave And Optoelectronic Interactive Devices.

摘要

Electro-optic (EO) devices that modulate optical signals by electric fields are an integrative part of the photonics industry and device optimization is an important area of research. This dissertation research has been carried out to study and further develop the subject of piezoelectric resonance enhanced electro-acoustic-optic process, in order to improve the sensitivity and efficiency of electro-optic sensors and to explore novel applications. The behavior of both piezoelectric-defined (or intrinsic piezoelectric materials) and engineered periodic structures are reported. The piezoelectric response of the surface displacement of samples is investigated using an ultra-high frequency laser Doppler vibrometer. A two dimensional view of the surface is obtained and the surface displacement, velocity and acceleration are compared to the electro-optic response under the resonant condition. The acousto-optic figure of merit (FOM) as a function of the material's refractive index, density, effective AO coefficient and the velocity of the acoustic wave in the material, is also investigated. By examining the directional dependent velocity, acousto-optic coefficients, and refractive index, the acousto-optic FOM can be calculated and plotted in all directions revealing the optimal crystal orientation to maximize coupling between the optical and acoustic waves. A finite element model was developed to corroborate the improved interaction. The model examines the diffraction that occurs on the optical wave as it travels through an acousto-optic medium. The combined information gained from commercially available multiphysics-based modeling platforms is shown to be an effective means of predicating acousto-optic device functionality.