Raman spectroscopy of single crystals using circularly polarized and twisted light

Title: Raman Spectroscopy of Single Crystals Using Circularly Polarized and Twisted Light Author: Anastasiia Pylypets Institute of Physics of the Czech Academy of Sciences: Department of Dielectrics Supervisor: Jiří Hlinka, Department of Dielectrics, Institute of Physics of the Czech Academy of Sciences Abstract: The use of twisted light in Raman spectroscopy has attracted interest due to its ability to change Raman selection rules. Laser beams with a helical phase carrying orbital angular momentum (OAM) have been used in optical trapping and astronomical imaging, and their structured wavefront offers new possibilities for probing phonon modes that remain inactive under linearly polarized light. Given the simplicity and accessibility of Raman spectrometry, incorporating OAM light could significanly broaden phonon mode analysis in materials. In the thesis, we test a Raman spectrometer setup employing vortex filters and investigate two materials: Bismuth Germanate (BGO) and α-quartz enantiomers. BGO is a cubic crystal with 27 Raman-active modes and a silent A2 mode, is predicted to activate the A2 mode under twisted light. α-quartz is a chiral crystal known to interact with circularly polarized light, was studied using various vortex filter combinations to explore potential interactions between chiral...