Doctoral thesis on 2-level solid state masers at University of California at Berkeley, 1956-1959; beginnings of his work on integrated optics at California Institute of Technology, mid-1960s. Research at Bell Telephone Laboratories on noise, parametric amplifiers, doped crystal lasers, and semiconductor lasers, and his mode-locking studies at Watkins-Johnson and Lockheed. Role of consultancy at Hughes Aircraft Co. on research in phase-conjugated optics.