Materials and Devices for Optical Switching and Modulation of Photonic Integrated Circuits

The drive towards photonic integrated circuits (PIC) necessitates the development of new devices and materials capable of achieving miniaturization and integration on a CMOS compatible platform. Optical switching: fast modulation and add-drop switches, key components in a PIC, were investigated. A MEMS-based approach was utilized to control switching in planar ring resonator waveguide structures. A switch extinction ratio of 15 dB, switch speed of 60 ps and 1 mW operating power were demonstrated. A metal-insulator transition material, V0 2, was identified as a material with potential for enhancing the switch speed with speeds in excess of gigahertz rates with minimal device footprint. Fundamental material transport properties and nonstoichiometry in V0 2 were characterized. Nonstoichiometry as high as 5 % was measured. A Frenkel defect model was used to describe the behavior in V0 2 in which vanadium interstitials were attributed to be the dominant ionic defect in the reducing regime. Frozen-in vanadium interstitials, acting as shallow donors lying 20 meV below the conduction band in the semiconducting phase, enhance the low temperature conductivity and free carrier concentration