Welcome to the Structured Light Laboratory

We are a small, diverse and dynamic group in the School of Physics at the University of the Witwatersrand in South Africa.

Our history traces back to traditional laser beam shaping for commercial applications, then mathematical optics and its applications at the CSIR National Laser Centre, to the new laboratory at Wits, started in 2015. Here we look at Structured Light and its applications. 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. By Structured Light we mean the creation of arbitrarily complex light patterns through the control of light’s polarisation, amplitude and phase. We used these tools to create accelerating light, non-diffracting light, vector light fields and light carrying optical vortices and orbital angular momentum. We also use these tools to unravel light, what we call modal decomposition, or a “pattern sensitive detector”. We create these fields by a range of techniques, but primarily using digital holograms written to spatial light modulators for the all-digital control of light. Our present research topics include:

Developing digital toolkits for creating and detecting spatial modes of light
Classical entanglement
Vectorially structured light
Orbital angular momentum
Free-space optical communication with patterns of light
Atmospheric turbulence
Quantum imaging
Intelligent structured light by machine learning
Quantum optics with structured photons
Quantum communication, teleportation and entanglement swapping
Quantum information processing with high-dimensional entangled states
High-dimensional quantum state engineering
Structured light lasers
High-power structured light and its applications

The work is carried out at both the classical and quantum levels and includes topics that range from purely theoretical to purely experimental, with a healthy dose of computational tools and instrument interfacing techniques.

We aim for impact through science. We are in the ‘century of the photon’, with the hope of harnessing light for a brighter future. In the Structured Light Laboratory we develop novel methods to tailor light, much like tailoring cloth, fashioning customised light fields for applications in imaging, communication, health and metrology. These include structured light for non-invasive nanoscale optical metrology, optically controlled lab-on-a-chip chemistry for probing environmental pollutants, fast and secure communication to bridge the digital divide in Africa while bringing South Africa closer to a future quantum network, and imaging hidden structures with a quantum microscope.