Conference Agenda

We use spatial light modulation to investigate the diffractive effects of gravitational lensing in the laboratory. Using this new platform for laboratory astrophysics, we can overcome the coherence challenges that prevent the observation of diffraction in astronomical imaging. These studies will inform gravitational lensing of gravitational waves when imaging of gravitational waves becomes available. Our previous work involved studying lensing by a single mass, symmetric and elliptical. This work focuses on the patterns produced by a binary-mass system. We observed rich 2-dimensional interference patterns bounded by caustics. Comparison of experimental results with preliminary theoretical calculations is excellent.

The dichroic macular pigment in the Henle fiber layer in the fovea enables humans to perceive entoptic phenomena when viewing polarized blue light. In the standard case of linearly polarized stimuli, a faint bowtie-like pattern known as the Haidinger's brush appears in the central point of fixation. As the shape and clarity of the perceived signal is directly related to the health of the macula, Haidinger's brush has been used as a diagnostic marker in studies of early stage age-related macular degeneration (AMD) and central field visual dysfunction. However, due to the weak nature of the perceived signal the perception of the Haidinger's brush has not been integrated with modern clinical methods. Our group has developed techniques to increase the strength of the perceived signal by employing polarization coupled orbital angular momentum states. We successfully achieved the creation of stimuli with higher numbers of azimuthal fringes, enabling the perception and discrimination of Pancharatnam-Berry phases, measuring the visual angle of entoptic phenomena, retinal imaging using structured light, and the creation of radially varying entoptic stimuli. Our current studies are focusing on applying the structured light toolbox that we developed to subjects that suffer from ocular diseases such as AMD.

Photonic Orbital Angular Momentum (OAM) is becoming a pertinent quantum variable for atom-light interaction, in particular for non-linear interaction which leads to photon entanglement and OAM-entanglement. With two 4-levels atomic schemes, we show that Four Wave Mixing addressed by vortex beams leads to very different OAM-entanglement especially for large OAM values.

We introduce a cutting-edge technique utilizing structured light, specifically linear photonic gears, for ultra-sensitive transverse displacement measurements. Light propagation through periodic liquid-crystal metasurfaces translates displacements into polarization rotations of a laser beam. The system's sensitivity can be enhanced by decreasing the spatial period of these components, achieving resolutions of 400 pm under standard conditions and potentially 50 pm with optimized setups. This compact, cost-effective approach offers high stability and precision, demonstrating significant advancements in applications such as precision component monitoring, material property assessments, and nanofabrication, showcasing the transformative potential of structured light in precision measurement technologies.

We consider a far-red-detuned optical cavity, driven by a pump, which contains an ultracold atomic medium. Using coupled partial differential equations which describe the evolution of the atomic and optical fields, we demonstrate that our model leads to novel self-structuring, led by the optical field through the dipole force, within the ultracold atomic medium. Introducing OAM to the optical pump, we demonstrate that these structures may be made to rotate, forming atomic fields analogous to persistent phase currents.