TUNING AND OPTOMECHANICS OF COUPLED PHOTONIC CRYSTAL NANOBEAM CAVITIES

Abstract

This thesis focuses on mechanical tuning and optomechanics of photonic devices based on coupled photonic crystal nanobeam cavities, with studies including nano fabrication process development, device tuning with NEMS actuators, investigation of optical gradient force and tunable cavity optomechanics. High efficiency resonance tuning by electrostatically shifting the coupled nanobeam cavities in the lateral direction has been achieved. Coupling strength tuning over wide range with high precision is demonstrated and the repeatability and dynamic tuning are also proven. Based on the lateral tuning, lateral shearing optical gradient force is predicted and demonstrated in experiments. It is the first study of such lateral shearing optical force according to the author’s knowledge. The study of optical force has great potential in all-optical system development. Thus, a more attractive area, cavity optomechanics, is also investigated in this thesis and a tuning method of cavity optomechanics is proposed and experimentally demonstrated.