| This thesis is concerned with the design, simulation and integration of control mechanisms for variable optical subsystems. After a brief overview of the current market for optical components, this themed portfolio focuses on the following four research projects. The first project deals with the specification and design of a control system and management interface as system-on-chip (SoC) for a range of passive thermo-optic planar lightwave circuits (PLCs) in silica-on-silicon technology. A detailed specification, which includes a requirements analysis and the proposed architecture of the SoC, is presented. The second project introduces a novel control system for a reconfigurable gain equaliser, based on a coherent two-port lattice-form optical delay-line circuit in PLC technology. The established synthesis method is extended by a least-square optimisation of a more accurate device model, whose parameters can be gained through device characterisation. This allows single-shot reconfiguration without the need for iterative adjustment using optical feedback. Measurements from a five-stage device agree well with simulated data. In the third project, the design, simulation and integration of open and closed-loop control algorithms for a micro-electro-mechanical system (MEMS) based variable optical attenuator (VOA) in planar hybrid technology is presented. The feedback algorithm uses adaptive gain to provide an order of magnitude improvement in worst-case response time over fixed-gain integral control. Simulations and measurements show a settling time of less than 20 times the sample period, independent of the working point on the non-linear DC transfer function. The fourth project evaluates the performance of an existing temperature control algorithm, which was implemented in an arrayed waveguide grating (AWG) subsystem. A dynamic model of the subsystem is developed and various operating conditions are validated by simulations. |
