Science Alert February 24, 2023 Ghost imaging involves the exploitation of non-local photon spatial correlations to image objects with light that has not interacted with them and, using intelligent spatial scanning with projective masks, reduces detection to a single pixel. Despite many applications, extension to complex amplitude objects remains challenging. Researchers in South Africa revealed that the necessary interference for phase retrieval was naturally embedded in the correlation measurements formed from traditional projective masks in bi-photon quantum ghost imaging. Using this, they developed a simple approach to obtain the full phase and amplitude information of complex objects. They demonstrated straightforward […]
Tag Archives: S&T South Africa
Distortion-free structured light
Phys.org February 7, 2023 Both real-world and experimentally simulated turbulence conditions have revealed that free-space structured light modes are perturbed by turbulence resulting in both amplitude and phase distortions, and consequently, much attention has focused on whether one mode type is more robust than another, but with inconclusive and contradictory results. Researchers in South Africa have shown complex forms of structured light that are invariant under propagation through the atmosphere: the true eigenmodes of atmospheric turbulence. They provided a theoretical procedure for obtaining these eigenmodes and confirmed their invariance both numerically and experimentally. According to the researchers although they have […]
Sharing a secret…the quantum way
Science Daily July 31, 2020 By taking advantage of the high‐dimensional Hilbert space for orbital angular momentum and using Perfect Vortex beams as their carriers, researchers in South Africa have presented a proof‐of‐principle implementation of a high‐dimensional quantum secret sharing scheme. This scheme is experimentally implemented with a fidelity of 93.4%, for 10 participants in =11 dimensions. The implementation can easily be scaled to higher dimensions and any number of participants, opening the way for securely distributing information across a network of nodes…read more. TECHNICAL ARTICLE
Structured light promises path to faster, more secure communications
Eurekalert November 5, 2019 Researchers in South Africa review the progress being made in using structured light in quantum protocols to create a larger encoding alphabet, stronger security and better resistance to noise. Since patterns of light can be distinguished from each other, they can be used as a form of alphabet. Its information capacity is much higher than polarized light and security is stronger, and the robustness to noise is improved. It turns out that many protocols can be efficiently implemented withotterns of light. Unfortunately, the toolkit to manage these patterns is still underdeveloped and requires a lot of […]
Structured light promises path to faster, more secure communications
Science Daily October 29, 2019 Researchers in South Africa review the recent progress in the emergence of a second quantum revolution ushering in control of quantum states, outlining the core concepts in a tutorial manner before delving into the advances made in creation, manipulation, and detection of such quantum states. They cover advances in using orbital angular momentum as well as vectoral states that are hybrid entangled, combining spatial modes with polarization to form an infinite set of two-dimensional spaces: multidimensional entanglement. The authors highlight the work in pushing the boundaries in both the dimension and the photon number, before […]