| This thesis explores a hardware implementation of a modulated white interferometer. Voice coil actuators are used to actively modulate one optical path of the interferometer and create a temporal interference signal. This signal is used to calculate a centroid with respect to the modulation profile and thus, locate the zero optical path difference (OPD) with sub-wavelength accuracy. Monitoring changes in the position of the zero OPD point can indicate motion of a structure incorporated in the interferometer architecture.;An optimal feedback controller is designed to ensure the modulation trajectory is accurate and precise. A complicated mode logic system is developed to provide triggering for calculation of the centroid at the end of each half-cycle of modulation. The system is then digitally implemented using a Texas Instruments TMS320C40 based digital signal processing system. Finally, the performance of the system is characterized and other applications discussed. |
