| Wavelength-division-multiplexing (WDM) technology has been widely employed in current optical communication systems. Optical signal processing and methods to increase the spectral efficiency of the system have attracted tremendous research interest due to the surging bandwidth and speed requirements introduced by Internet traffic. These two areas demand high-performance optical components. To improve component performance and reduce its cost, planar lightwave circuits (PLC) technology provides a very promising platform for component integration. Among many PLC-based device structures, micro-ring structures are especially attractive due to their versatile functionality and compact size. In this thesis, we examine several micro-ring based PLC devices, namely filter, interleaver, and switch array for use in optical communication systems.;We describe in detail the design concerns, testing methodologies, and control schemes for these key, microring applications. By expanding low-coherence interferometric measurements, we have characterized the behavior of these components and demonstrated a systematic thermal-control scheme for the micro-ring based filter and interleaver. We further introduce a more complicated ring-based switch array (which can be used as a tunable filter array) based on the operational principles and control capability of the micro-ring filter. We also compare our measurement results of devices fabricated by commercial vendors with our analysis models.;Although this thesis is mainly about micro-ring-based optical filters, interleavers, and switches, other PLC based devices are also included in this work due to their relevancy. One of these is the AWG. AWG is widely used in the optical communication systems as a (de)multiplexer. We introduce a scheme using AWG as a testing vehicle to investigate the mode profile of waveguides. The motivation for this modeling is the system requirements on the width and flatness of the (de)multiplexer passband. The passband width and flatness of any AWG channel highly depends on its input waveguide design. Based on the low-coherence interferometric method, we propose a systematic measurement and analysis scheme to characterize the input waveguide mode profile and demonstrate its effectiveness for Gaussian, multimode interferometer (MMI) and synchronized waveguides designed by commercial vendors. |
