Controlling light transport through fibre optics
Transport of light within a multimode fibre introduces apparent randomisation of laser beam amplitude, phase and polarisation. We develop methods to analyse and quantify the randomisation and to shape the light output of multimode fibres using the principles of digital holography. Adopting methods of advanced photonics in turbid environments and high-performance computational technology we can empirically capture the way the light signals are scrambled and utilise the information to predict how will any light signal sent into the fibre look on the other side. This in turn allows us to design and synthesise complex optical fields that although looking entirely random at the input side of the fibre will take the shape of any desirable optical field after propagation through the fibre. These studies are of paramount importance for our advanced imaging geometries but also for opto-fluidics and optical manipulation (on-chip geometries) as well as telecommunications. The example shows the fibre output light used for optical manipulation of silica beads.
T Cizmar & K Dholakia Shaping the light transmission through a multimode optical fibre: complex transformation analysis and applications in biophotonics. Optics Express 19(20) 18871-18884 (2011)
T Cizmar & K Dholakia Exploiting multimode waveguides for pure fibre-based imaging. Nature Communications 3 1027 (2012)