The thesis contains fundamental theoretical and experimental research related to classical coherence theory and electromagnetic optics. The work covers two main topics that may find important applications in polarimetric and interferometric investigations of optical structures and materials.
The first topic encompasses theoretical studies of novel remote sensing techniques intended for spectral characterization of reflective and transmissive objects in ellipsometry and polarimetry. The methods are based on optical correlation imaging and make use of spatially incoherent classical light sources with Gaussian statistics and the measurement of intensity correlations. The ellipsometric schemes are designed to characterize both homogenous and inhomogeneous reflective planar samples. The ellipsometers are shown to be relatively insensitive to instrumentation errors and do not require source or detector calibration. Our polarimetric technique extends the use of intensity measurements to the detection of Stokes-parameter correlations and provides new information about the use of polarization state correlations in general. The design can determine the transmission matrix of any polarization sensitive object and is insensitive to inaccuracies caused by turbulent media.
The second topic covers theoretical and experimental studies related to the interference of electromagnetic waves. We demonstrate for the first time the existence of the Pancharatnam–Berry geometric phase in Young's double-pinhole experiment and in temporal interference of light. The phase appears due to the periodic polarization state modulation caused by the superposition of two fully coherent and polarized beams. Two different formulas for the phase are established in terms of the intensities of the interfering fields together with either their polarization states or the visibility of the intensity variation.
Further, we discover that the geometric and dynamical phases associated with the interference are intertwined in such a way that one cannot be changed without altering the other. The results are verified experimentally by measuring the beam Stokes parameters and the amplitude of the interference intensity modulation as well as using genuine interferometric phase measurements. Our work illustrates that two-beam interference is not yet fully understood by connecting to the phenomenon new fundamental characteristics arising from the Pancharatnam–Berry phase.
The doctoral dissertation of Master of Science Antti Hannonen, entitled Optical correlation imaging and geometric phase in electromagnetic interference will be examined at the Faculty of Science and Forestry on the 9th of December online. The opponent in the public examination will be Professor Paul Urbach of Delft University of Technology, and the custos will be Professor Tero Setälä of the University of Eastern Finland. The public examination will be held in English.
