Optical nanoelecteromechanical systems (NEMS) devices and nano fabrication processes
Date of Issue2015
School of Electrical and Electronic Engineering
This doctorate thesis focuses on the design, fabrication and testing of novel optical nanoelectromechanical systems (NEMS) devices. Specifically, a nano-actuator, a variable optical attenuator (VOA) and an optomechanical memory have been fabricated by nano-silicon-photonic fabrication processes. The first part of the thesis reports a NEMS actuator driven by optical gradient force. The optical force driven actuator realized by Q-factor modulation of the ring resonator can achieve an actuation range of 14 nm with a resolution of 0.18 nm. An optical displacement sensor is integrated to measure the actuation distance through optomechanical effects. The second part focuses on the development of a NEMS variable optical attenuator. In this design, optical attenuation is realized via a nano-waveguide-based optical directional coupler where the gap between waveguides is modulated by optical gradient force. Optical intensity can be attenuated to 10% of the original value with an actuation distance of at least 150 nm by tuning the wavelength of control light by 2 nm. The third part works on the optomechanical memory based on an optical force-induced bistability. A doubly-clamped silicon beam is actuated by the optical gradient force and bistability occurs as a result of nonlinearity of the optomechanical effects. The memory states can be switched by controlling the optical power from -10 dBm to -6 dBm. The switching speed is less than 150 ns.
DRNTU::Engineering::Electrical and electronic engineering::Microelectromechanical systems