Alvin A. H. Nielsen, physicist in molecular spectroscopy, was born May 30, 1910, in Menominee, Michigan. Nielsen graduated from the local high school in 1927 and entered the University of Michigan, from which he earned his B.A. in 1931, M.A. in 1932, and Ph.D. in 1934.
Nielsen accepted a position as instructor in the department of physics at the University of Tennessee in 1935. He became a full professor in 1946 and succeeded Kenneth Hertel as department head in 1956. Nielsen achieved national and international recognition for his work in molecular spectroscopy and authored eighty-five publications. During World War II Nielsen joined a war research team at Ohio State University, where he worked on infrared detectors. When he returned to Knoxville after the war, Nielsen became one of the first consultants employed by the Gaseous Diffusion Plant at Oak Ridge, where he led a research team that specialized in studies of halogen-substituted formaldehydes, which have been found to be important in the pollution of the atmosphere. Nielsen's early work continues to provide information for current pollution studies.
In 1951 Nielsen became the University of Tennessee's first Fulbright Scholar and spent a year at the Institut d'Astrophysique de Cointe in Liege, Belgium. He proved adept at building national and international connections for UT. As department head (1956-69), he played a major role in developing the Oak Ridge connection that provided dual appointments for UT faculty and opened federal research facilities to university scientists. With Hilton Smith of the chemistry department, he acquired a ten-year faculty endowment grant from the Ford Foundation. In 1969 the National Science Foundation named the physics department a Center of Excellence and awarded it a $750,000 matching grant.
Nielsen was named dean of the College of Liberal Arts from 1963 to 1977. Nine new departments or programs were added, and six new buildings were constructed. In 1972-73 he served as chairman of the American Council of Academic Deans. When Nielsen retired as dean, Mayor of Knoxville Randy Tyree declared May 23-29, 1977, as “Alvin H. Nielsen Appreciation Week.” In 1980 the UT physics building was named in his honor.
Nielsen was a Fellow of the American Physical Society, of the American Association for the Advancement of Science, and of the Optical Society of America. He married Jane Ann Evans of Columbus, Ohio, in 1942. They were the parents of one daughter, Margaret A. Nielsen Wayne. Alvin Nielsen died in Knoxville on November 3, 1994.