During this talk, we will discover how lasers made from liquid crystals offer new potential for the development of low-cost tuneable lasers with bespoke emission characteristics, and with applications including biomedical imaging, 2D and 3D displays and anti-counterfeiting inks. First we discover how the selforganising properties of chiral nematic liquid crystals can be used in "bottom-up" assembly to fabricate tuneable one-dimensional photonic band-gap materials. Liquid crystals can therefore act as high-finesse mirrorless microresonators, and when doped with organic dyes enable highly-efficient photonic band-edge lasing, with slope efficiencies in excess of 60%. We will discover how gradient-pitch chiral nematics and novel adaptive holographic pumping techniques can be used to enable continuous wavelength-tuning and multiple simultaneous polychromatic laser emissions. Furthermore, we learn how the polymer-dispersion of liquid crystals enables the development of paintable and ink-jet printable laser formulations, suitable for anticounterfeiting applications. Finally, we look forward to new liquid crystal laser systems currently in development here in Edinburgh, and discover how these sources can be used to develop new, low-cost, point-of-care biomedical imaging and diagnostics tools.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..