Structured Laser Wavefronts for Raman Spectroscopy and Single Molecule Spectroscopy
Abstract
Wavefront shaping is a powerful technique that revolutionized many aspects of our lives. It allowed us to see farther galaxies and smaller objects better than ever. It drastically changed the field of optics in general and imaging in particular, providing the possibility to focus light through highly scattering media and restore a light beam profile after major distortions. Automatization of wavefront shaping with adaptive algorithms sped up the process and added the flexibility of changing beam wavefront parameters “on the go”. At the same time, with the advancement of nanotechnologies we gain a privilege to study how macroscopic changes in a laser beam shape affect single atoms on the nanoscale.
Our research focuses on extending the applications of laser wavefront shaping in the area of linear and nonlinear optics, spectroscopy, imaging and light-matter interactions. We aim to push limits of existing spectroscopic techniques (e.g. Raman spectroscopy) and develop fundamentally new applications for shaped laser beams. Optical vortices - structured light modes - are another type of shaped beams, rapidly gaining popularity and being used, for example, for encoding quantum information onto the light beam. The studies on how optical vortex modes pass their quantum properties (such as orbital angular momentum) to a single molecule or an atom, is an intriguing question that is still underexplored. Moreover, left- or right-handedness of an optical vortex makes it an efficient tool for studying molecular chirality on a single-molecule scale. Experiments in this field are highly multidisciplinary and require the combination of robust chemical sample preparation, precise optical alignment and manufacturing of complex nanostructures. In this dissertation we gather all the necessary technologies and procedures, conduct optical simulations and build the experimental setup that allows us to probe the chirality or the dipole-forbidden transition of a single molecule with the help of shaped laser beams and nanostructures.
Citation
Shutova, Mariia (2020). Structured Laser Wavefronts for Raman Spectroscopy and Single Molecule Spectroscopy. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /192451.