Date of Award
2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Physics
Department
Physics
First Advisor
Feruz Ganikhanov
Abstract
The research efforts have been focused on studying of ultrafast vibrational dynamics in ultraviolet (UV) bandgap oxide crystals and a recombinant protein. Namely, I have studied Raman-active lattice modes in technologically important non-linear optical materials like orthorhombic potassium titanyl phosphate (KTiOPO4or KTP), and rhombohedral periodically poled lithium niobate (poled LiNbO3 or PPLN). The dynamics of main phonon lines have been traced with better than 120 fs time resolution using Coherent Anti-Stokes Raman Scattering (CARS) yielding directly in longitudinal and transverse optical phonon lifietimes and proving homogenous character of Raman line broadening in these highly non-centrosymmetric materials. Coherent Raman modes beatings have been also observed and traced on ultrafast time scale. The time-resolved CARS technique (TR-CARS) is then extended to the SARSCoV-2 Spike Receptor Binding Domain (RBD)-His protein in aqueous solution, where picosecond vibrational decay times reveal energy-dissipation rates under room temperature conditions. Overall, the work demonstrates that TR-CARS, that makes use of tailored femtosecond optical excitations, provides a valuable quantitative spectroscopy technique for probing vibrational relaxation and dephasing in both complex oxide crystal materials and biomolecular solutions.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Singhapurage, Helani, "TRANSIENT DYNAMICS OF LATTICE AND MOLECULAR VIBRATIONS IN INORGANIC CRYSTALS AND PROTEIN" (2026). Open Access Dissertations. Paper 4598.
https://digitalcommons.uri.edu/oa_diss/4598