Research on nonlinear optics at MIT, 1962-1967. Other laser research in MIT period. Responsibilities as Vice-President and Director of Research at Institute for Defense Analysis (IDA), 1959-1961. Interest at IDA and ARPA in lasers and laser weaponry. Contemporary evaluations of Robert Dicke’s superradiance paper. Townes’s change of research field from nonlinear optics to radio astronomy in the late 1960s.