Founder of quantum optics dies

17 Jun 2002

Leonard Mandel, one of the world's leading physicists, died on Friday February 9th

Leonard Mandel, DuBridge professor emeritus of physics and optics at the University of Rochester in the US, has died at the age of 73. He is survived by his wife, two children, four grandchildren and his father. Mandel was one of the founders of quantum optics and was the first to observe certain phenomena predicted by quantum theory.

Mandel was at the forefront of a movement in which the influence of quantum theory expanded to touch on every area of physics. It was he who demonstrated "quantum entanglement" - the idea that any action has an effect on another, seemingly unrelated, action elsewhere. Mandel and his students were also the first to demonstrate the interference of single photons with themselves; the first to demonstrate non-classical interference between two photons; and the first to design and carry out an experiment to observe "photon antibunching", demonstrating that a single atom illuminated by a laser beam emits photons that are uniformly spaced in time.

"Len systematically tested quantum theory, producing the finest experiments in the world to test the foundations of quantum mechanics," said longtime colleague and friend Emil Wolf, Wilson professor of physics and optics at the university. "He was an excellent teacher and a first-class researcher. He was truly one of the founders of quantum optics. He was also a kind man and incredibly generous, praising my work when the reality is that he was a much better physicist than I."

Mandel's work helped form the basis of a growing field of knowledge that today includes quantum encryption, quantum computing, and quantum communications.

He was considered to be an outstanding teacher and was recognized with nearly all of the honors available to an optical physicist, including the Frederic Ives Medal and the Max Born Award of the Optical Society of America, the Italian National Research Council's Marconi Medal and the Thomas Young Medal from the UK's Institute of Physics. He was a fellow of the American Physical Society, the Optical Society of America and the American Academy of Arts and Sciences. He wrote more than 300 scientific papers, including one with Wolf on the coherence properties of optical fields, which became one of the most cited articles published in physics.
Extracted from an obituary courtesy of the University of Rochester.