Future Optical communications might be more secure thanks to Professor John Donegan and team for their research conducted at the Trinity College in Dublin, Ireland. The research team found a new property of light while passing it through crystals. Usually, when light hits our eyes, the spinning photons twist infinitesimally. In Quantum physics, the force of the twist/spin called the angular momentum has been thought to be a direct multiple of a constant called Planck’s constant. However, John Donegan and team discovered a new form of light with an angular momentum that is exactly half of the conventional one. The team believes the new discovery would have practical applications in secure optical communication.
The research team devised an experiment to effectively reduce the number of dimensions that the light operates in. They passed the light through a crystal, turning the light beam into a hollow cylinder with a “screw-like structure.” The team built a device to measure the angular momentum and conducted measurements (measuring the angular momentum) by passing the light through a crystal. They allowed the light to bypass the crystal and compared the results. When the light was not passing through the crystal, the spin was an exact multiple of Planck’s constant, confirming to the conventional observations. When the light was passed through the crystal, the angular momentum shifted by one-half.
Trinity College is the sole constituent college of the University of Dublin, a research university in Ireland. The college was founded in 1592 as the “mother” of a new university, modelled after the collegiate universities of Oxford and of Cambridge, but, unlike these, only one college was ever established; as such, the designations “Trinity College” and “University of Dublin” are usually synonymous for practical purposes. It is one of the seven ancient universities of Britain and Ireland, as well as Ireland’s oldest university.
Trinity College was originally established outside the city walls of Dublin in the buildings of the dissolved Augustinian Priory of All Hallows. Trinity College was set up in part to consolidate the rule of the Tudor monarchy in Ireland, and it was seen as the university of the Protestant Ascendancy for much of its history. Although Catholics and Dissenters had been permitted to enter as early as the end of the XVIII century (1793), certain restrictions on their membership of the college remained until 1873 (professorships, fellowships and scholarships were reserved for Protestants). From 1956 to 1970, the Catholic Church in Ireland forbade its adherents from attending Trinity College without permission from their archbishop. Women were first admitted to the college as full members in January 1904.
CRANN is Trinity College Dublin’s largest research Institute, delivering world-leading nanoscience and material science research, funded by Science Foundation Ireland. CRANN has Ireland’s most advanced microscopy instrumentation; extensive research engagements with industry and is committed to the commercialization of research.
Prof. John Donegan and team has research interests in Nanophontics within two main areas. The first is quantum dot interactions; they are studying fluorescent quantum dot systems synthesized through colloidal processes. The other main study focus is micro-cavity interactions where they investigate mechanisms in coupled photonic micro-resonators which result in modified properties, such as directional emission, modification of the modal structure, and localized field confinement
Prof John Donegan received BSc and PhD degrees from University College Galway in 1982 and 1986. He had post-doctoral appointments in Lehigh University, Bethlehem, USA and in Max-Planck Institut für Festkörperforschung, Stuttgart, Germany. He was appointed to the academic staff in Trinity College Dublin in 1993, he is now a Fellow of Trinity College Dublin and Professor of Physics. He is a fellow of the Institute of Physics and the Institute of Nanotechnology, a senior member of the IEEE and the American Physical Society. He was recently the Head of School of Physics in TCD. Professor Donegan has collaborations with Ludwig-Maximilians-Universitaet Muenchen, University of Dresden, Université de Reims, and the Bell Laboratories, New Jersey. He has published 153 papers in journals and conference proceedings as noted in the web of science. He has made 15 patent applications.