William M. Yen

William YenLamar Dodd Award 2005

William M. Yen has been studying the optical properties of solids, especially those that emit light, for more than 40 years. He began working in this area as a post doctoral associate in Nobel Laureate Arthur Schawlow’s laboratory at Stanford University. His research has influenced “every branch of solid state physics, from the study of electronic and magnetic to vibrationalproperties of solids,” the nominators said.

Dr. Yen’s research has contributed to development of improved laser materials and phosphors and has stimulated much theoretical work. Many of his papers opened new avenues of research, said George Imbusch, Professor Emeritus of Physics at the National University of Ireland, Galway. He is regarded as “the leading active researcher in the field of optical properties of magnetic ions in solids worldwide,” said David Huber, a physics professor at the University of Madison-Wisconsin.

Dr. Yen invented and patented a new breed of glow-in-the-dark pigments or “long-persistence phosphors.” After just a few minutes’ exposure to light, these inorganic compounds emit a bright glow for more than 20 hours — twice the time of similar substances. The low-cost, non-toxic materials can be engineered to produce any color. Future applications may include emergency signage, military uses, toys and clothing. Dr. Yen also co-edited The Phosphors Handbook, a technical manual of phosphor properties and uses that is the standard reference book for the field.

He was an early pioneer in the use of lasers to study condensed matter physics, a research area that underpins recent advancements in electronics, optics and computer technology. He also was a principal in leveraging a method called “laser-heated pedestal growth” for creating optically active crystal fibers that previously were too costly or impractical to make. X-ray and UV imaging techniques developed in his laboratory are now widely used in materials and biological microscopy.

A much sought-after speaker, in the past six months Dr. Yen gave keynote plenary addresses at four international conferences. He has published more than 275 refereed journal articles, attracted more than $20 million in external funding and has been awarded four patents. He is a Fellow of the American Association for the Advancement of Science, co-founder of two conference series and a prominent physicist in professional societies.