Stuart M. Johnson Jr. ’51, a physicist who was equally at home in the research laboratory and as a manager of research, engineering, and operations, died on March 14 in Deltona, Florida. Stuart’s research interests were in photonics and opto-electronics, with an important focus on thin films. Applications of his work include night-vision devices and photomultipliers for use in the aerospace industry. His 36-year working career included assignments with Schlumberger Well Surveying Corp., ITT Industrial Laboratories, Raytheon Co., Hamamatsu Photonics, and Princeton University’s Advanced Technology Center. His research findings led to several articles in scientific journals. Among other awards, he received a letter of commendation from Princeton. After retiring in 1992, Stuart founded and headed Johnson Management Co. in Honolulu to oversee his family’s real estate holdings in Hawaii. He also indulged his lifelong enjoyment of classical music and opera. Stuart received both bachelor’s and master’s in physics from Dartmouth. His undergraduate years were interrupted by a two-year stint working for the Yokohama Signal Depot in Japan as a means of financing the rest of his formal education. Upon his return to Dartmouth, he served as the physics department’s youngest teaching fellow, was a member of the wrestling team, and was active in the Outing Club. He later earned an executive management certificate from Indiana University Graduate School of Business. He is survived by his wife, Joan, four children, and three stepchildren.