The interview begins with a discussion of Giallorenzi’s youth, including his education and anecdotes about his early jobs, as well as his undergraduate and graduate work at Cornell University and his work on the scattering of laser light in Chung Tang’s laboratory there. Giallorenzi recounts his first laboratory job at GT&E Laboratories working on laser displays and arc lamps, and his move soon thereafter to the Quantum Optics Branch at the Naval Research Laboratory in Washington, D.C. He discusses his work at NRL on fiber optics applied to sensor technology, including acoustic and magnetic sensors, and to pathbreaking R&D in microwave photonics. He also discusses his move to leading the then-newly created NRL Optical Techniques Branch, the departure of staff working on nuclear fusion to Livermore, and new R&D directions within his branch that were necessitated by the termination of work on liquid crystals. He recalls his relationship with NRL Director of Research Alan Berman, his promotion to Optical Sciences Superintendent, his division’s focus on high-power lasers, including MIRACL, and his decision to terminate a branch within the division. He further discusses his relationship with the Pentagon, status as a member of the Senior Executive Service, and experiences as a high-level administrator. The interview concludes with discussions of other technologies NRL worked on, the balance between basic and applied research at the lab, awards Giallorenzi has received, and his work with advisory panels, the Naval Center for Space Technology, and the Optical Society of America (now Optica).