Physics and Processing of Vanadium Dioxide for Optical Devices

Abstract

This dissertation examines the fundamental physical properties and material processing methods required to design and fabricate the next generation of optical modulators based on the vanadium dioxide metal-insulator transition. All-optical devices capable of performing at GHz speeds, which are only limited by the laser pulse duration, were designed, fabricated and tested. Broad-band pump-probe experiments examined the femtosecond phase transition dynamics in vanadium dioxide when excited at a range of wavelengths from 400 nm to 1500 nm and indicate that THz modulation speeds could be achieved. In addition, fabrication methods and doping were explored as paths to tune the phase transition properties. The optical modulator design and material performance are discussed in the context of current state-of-the-art technology.