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Structured Light Laboratory

The ability to tailor optical fields is an essential tool in a modern optics laboratory and has come of age with liquid crystal technology, allowing for the digital control of light. It is possible to create and study arbitrarily complex light patterns, e.g., accelerating Airy beams, non-diffracting Bessel beams, and light carrying optical vortices and orbital angular momentum, with applications in optical trapping and tweezing of single cells to optical lattices for control of atoms and ions. The tools of structured light naturally lead to the ability to encode information into patterns of light. This can be done at the classical level through mode division multiplexing, mooted as a potential solution to increasing bandwidth in optical fibres. Or it may be realise with high-dimensional entangled quantum states, suggested as the future of secure communication protocols. Our research builds competency in mathematical algorithms applied in optics, both theoretically and computationally, non-linear optics, diffractive optical elements, micro optics, adaptive optics, refractive beam shapers, digital holograms, spatial light modulators and wavefront sensing.

We welcome new partners with an interest to collaborate, and we have opportunities for Master’s and Doctoral studies, as well as vacation work for good students.


Beam Optics, for high bandwidth optical communication
We are studying how to pack information into light, transmit it over some distance, and then unpack the information on the other side.

Fibre Optics, for long-distance quantum/optical communication
We are studying how to propagate spatial modes of light over a distance in custom optical fibre, both in the classical and quantum regimes.

Optical Tweezers, for manipulation of micro-/nano-particles
We design and implement optical manipulation of particles using novel beam shapes for specific applications.

Quantum Optics, for high-resolution quantum imaging
We are studying how to achieve subdiffraction-limited resolution in three dimensions, using quantum entanglement as a resource.

Active Researchers

Prof. Andrew Forbes

Andrew received his PhD (1998) from the University of Natal, and subsequently spent several years working as an applied laser physicist, first for the South African Atomic Energy Corporation and then later in a private laser company where he was Technical Director. Andrew sits on several international conference committees, chairs the SPIE international conference on Laser Beam Shaping and is Chair of the OSA's Holography and Diffractive Optics group. He is a member of the Academy of Science of South Africa and a Fellow of SPIE.

Dr. Melanie McLaren

Melanie is a post-Doctoral researcher with an MSc in physics from the University of the Witwatersrand and a PhD in physics from the University of Stellenbosch. Her PhD focused on quantum entanglement of photons in the orbital angular momentum basis. Melanie also has experience in optical tweezing, where tightly focused laser light is used to manipulate micron-sized particles in three-dimensions.