Date of Award
Doctor of Philosophy
Electrical and Computer Engineering
Tunability and programmability are highly demanded for silicon photonic integrated circuits (PICs) to expand their applications in the next-generation photonics. The main objective of this thesis is to develop several reconfigurable and programmable photonic crystal (PC) devices.
In Chapter 2, we developed a relatively general nanofabrication process for integrating PC devices with movable mechanical components on silicon-on-insulator (SOI) wafers. We also investigated grating coupling technology, to facilitate coupling lights into and out of PC devices.
In Chapter 3, we developed an all-optical programmable PC device that integrates digital micromirror device (DMD), photo-responsive LC, and PC technologies. We demonstrated the functionality and programmability of the device, by forming a point-defect cavity, a straight waveguide, and a waveguide bend on the single device.
In Chapter 4, we developed two types of reconfigurable PC devices by leveraging the strengths of optical nanobeam and nano-electro-mechanical systems (NEMS) technologies. The first device consists of an array of movable nanobeams. Each nanobeam is an electrostatically tunable photonic element in a PC waveguide. We demonstrated the capability of the device to engineer different photonic bandgaps, by tuning one unit in group of two neighboring nanobeam units, tuning one or two in group of three units, and forming two reconfigurable PCs, on the single device. To achieve a higher-level integration, we also theoretically studied another reconfigurable PC integrating an array of mechanical tunable nanobeams with an array of fixed pillars into the top silicon layer of a SOI wafer.
In Chapter 5, we developed two tunable photonic crystal-cantilever cavity (PC3) resonators. The first device has an NEMS cantilever embedded into a L6 cavity in a PC slab. The second device has a similar cantilever to insert into a nanobeam-base waveguide. We studied bending characteristics of the cantilever and optical characteristics of these two devices at different applied voltages.
In Chapter 6, we conducted theoretical investigation on a nano-opto-mechanical reconfigurable PIC device consisting of an array of silicon plugs and a 2D PC slab. We theoretically demonstrated that a point-defect cavity, a line-defect waveguide, and a waveguide bend can be configured in the PC slab, by inserting different plugs into an air hole, a straight line of holes, and an L-shape line of holes.
Mao, Depeng, "Reconfigurable photonic crystal" (2015). Graduate Theses and Dissertations. 15970.