Award-winning Irish physicist and pioneer of laser physics who supervised over 60 PhD students during his long teaching career. He continued his work in laser applications at Trinity College, Dublin.
He worked as a telegraph boy and later studied at St. Columb's College.
He won the Institute of Physics Young Medal and Prize in 1975 and the Royal Society Royal Medal in 1982.
He has children named Mairead, Sean, Donal, Martin, and Ronan.
He was a renowned physicist like Danish Nobel Prize winner Niels Bohr.