From 1961 to 1963 he conducted research at a state laboratory near Moscow, and from 1963 to 1979 Kaplan worked at the Soviet Academy of Sciences. From 1979 to 1982 he worked at the Francis Bitter Magnetic Laboratory at the
Massachusetts Institute of Technology. Kaplan next worked as a professor of
electrical engineering at
Purdue University from 1982 to 1987. Finally, from 1987 until his retirement in 2016, he was a professor at Johns Hopkins University in the Department of Electrical and Computer Engineering. In addition to his other positions, Kaplan was a visiting researcher at the
Max Planck Institute for Quantum Optics in
Garching in 1981. He also served as a visiting professor at the
Weizmann Institute of Science, the
University of Ulm, and
Kyoto University. Kaplan was a theorist who made contributions to various areas of nonlinear optics and quantum electronics. His major contributions were in the fields of very-high order sub-harmonics generation, nonlinear interfaces, soliton physics, relativistic nonlinear optics, and others. ==Recognition==