SPIE Fellow Parameswaran Hariharan, renowned scientist, holographer, and author, died on 26 July in Berkeley, California, at age 89.
Hariharan worked at the National Physical Laboratory (NPL) in New Delhi (1949-51) and at the National Research Council, Ottawa (1951-54). On returning to NPL he received his PhD for his work on photographic resolving power. Subsequently, he became director of the laboratories at Hindustan Photo Films, Ootacamund (1961-71) and Senior Professor at the Indian Institute of Science, Bangalore (1971-73). He joined the Division of Applied Physics of Commonwealth Scientific and Industrial Research Organization (CSIRO) in Sydney in 1973 and retired as Chief Research Scientist (1991). He continued his research as an Honorary Research Fellow at CSIRO and an Honorary Visiting Professor at Sydney University. He was awarded the degree of DSc (hc) (2001) by the University of Sydney. He was a Jawaharlal Nehru Professor at the University of Hyderabad (1993) and a Visiting Scholar sponsored by the International Centre for Theoretical Physics (ICTP), Trieste, at the Raman Research Institute, Bangalore (1996-98).
Hariharan was famous for simplicity and the originality of his scientific approach to complex principles of both classical and modern optics. His books on holography and interferometry are extensively referenced by the global holography fraternity and optics students. His research contributions include the design of a three-beam interferometer, the double-passed Fabry-Perot interferometer, and the first practical radial-shear interferometer. He also made major contributions to digital phase-shifting interferometry, including a method for absolute measurements of deviations from flatness. He was the first to demonstrate achromatic phase shifting using the geometric phase, and made significant contributions to the study of quantum effects in optical interference.
Hariharan served as president of the Optical Society of India (1973) and the Australian Optical Society (1988). He was vice president (1984-87) of the International Commission for Optics and then its treasurer (1987-93). He was also a director (1991-94) of SPIE. Among his many international honors and awards, he received the Dennis Gabor Award in 1992 and the Gold Medal of the Society in 2001, both from SPIE.