Singularities are ubiquitous in nature. The theory of singularities appears in various branches of science and engineering. The amplitude and phase of an optical field are structured to generate optical vortices. These structured light beams with helical phase-fronts possess orbital angular momentum (OAM) of light. In the last 30 years, the OAM carrying beam has established itself as one of the most interesting optical modes, with relevance to optical communication, imaging, microscopy, optical manipulation, and elsewhere. We in our lab study the basics of singularities, their types, properties, generation, detection, and applications related to optical singularities.
Studies on polarization singularities
Our lab currently explores the interesting features of polarization singularities. Polarization singularities can be treated as a superposition of vortex fields on polarization basis. These vector vortex beams are exciting as it carries both spin angular momentum and OAM of light. Therefore, it acts as a promising candidate for various applications, including robust beam in atmospheric turbulence, optical chirality measurement, and edge enhancement.
Correlation study of orbital angular momentum(OAM) states of light
Optical field manipulation has become a topic of interest among research communities in recent years. Polarization Singular beams are known to carry orbital angular momentum (OAM) and spin angular momentum (SAM), which provide them to have a good deal of applications. As partially coherent beams are known to possess robust nature, which make them worthy in the space communication. So the manipulation of Correlation properties of polarization singular beams will provide an additional degree of freedom in many applictaions. By controlling the Correlation properties, one can modulate the polarization properties of such beams.
Study of singularity using meta-surfaces
Meta-surface provides the ability to structure the phase and polarization in an arbitrary manner, hence by using meta-surfaces one can easily generate polarization singularity with a single optical element. This helps in removing the complexity of interferometric setup as we are using a single component and set up in a more stable. Metasurfaces have a lot of applications like being widely used for realizing the wavefront shaping devices such as flat optical lenses, vortex beam converters, optical holograms, and wave plates.
Non-linear interaction of Polarization Singular beams
Non-linear optical processes provide a huge range of exciting features and enhance the scope of applications a structured beam can provide. We study the behaviour of polarization singularities under different non-linear optical phenomena.