The doctoral dissertation in the field of Physics will be examined at the Faculty of Science, Forestry and Technology, Joensuu Campus.
What is the topic of your doctoral research? Why is it important to study the topic?
This research focuses on the coherence and polarization of partially coherent light beams. The coherence properties of light fields have been instrumental in a broad range of practical applications including diffraction, propagation, and scattering of light. For instance, introducing partial coherence increases resistance to distortions such as turbulent media. Additionally, partially coherent beams are useful in optical coherence tomography, which can be used in medical diagnostics to image subsurface features of biological specimens. Other applications of partially coherent beams include optical manipulation, atom cooling, and atomic recoil lasing. Due to the vector nature of electromagnetic fields, establishing a rigorous theory taking the polarization properties of light fields into account is necessary. Polarization of light has also many applications such as in nanophotonics, spectroscopy, polarization imaging, and optical communication systems. The research presented in this thesis contributes to the knowledge of the fundamental physical properties and description of light beams and fosters potential advances in optical sciences and technology.
What are the key findings or observations of your doctoral research?
1. Theoretical introduction and experimental synthesis of novel, radially and azimuthally periodic fields.
2. A possible path for producing OAM beams with strong robustness against turbulence.
3. Paving the way for inverse design of correlation induced effects.
4. Introduction of the singular-value decomposition for the description of electromagnetic coherence of beam fields.
How can the results of your doctoral research be utilised in practice?
The experimental method could be utilized in generation of any physically realizable, spatially partially coherent beams with genuine correlation functions. The foundational research offers new insight into the modeling of partially coherent beams and into the structure of electromagnetic coherence. They may find potential applications, for instance, in optical communication, optical trapping, and optical shaping.
What are the key research methods and materials used in your doctoral research?
The research encompasses mainly theoretical work, involving analytic and numerical calculations. Point 1 above concerning synthesis of novel beams incorporates also experimental work.
The doctoral dissertation of Meilan Luo, PhD, entitled Partially coherent light beams: novel models and properties will be examined at the Faculty of Science, Forestry and Technology, Joensuu Campus. The opponent will be Professor Etienne Brasselet, University of Bordeaux, and the custos will be Assistant Professor Matias Koivurova, University of Eastern Finland. Language of the public defence is English.
