Arthur F. Turner

1906 - 1996

Arthur F. Turner (1906–1996): The Architect of Thin-Film Optics

Arthur Francis Turner was a foundational figure in the field of optical physics, specifically in the development of thin-film technology. While the average consumer may not recognize his name, billions of people benefit from his work daily—every time they look through a pair of non-reflective eyeglasses, use a high-end camera lens, or benefit from the thermal shielding of a satellite. Turner transformed thin-film coatings from a laboratory curiosity into a cornerstone of modern industrial and aerospace optics.

1. Biography: From Detroit to Berlin to Tucson

Arthur Turner was born in Detroit, Michigan, in 1906. His academic journey began at the University of Michigan, where he earned his Bachelor of Science in 1929. Seeking to study at the epicenter of physics during its "Golden Age," Turner moved to Germany to attend the University of Berlin.

In 1935, he completed his PhD under the supervision of Peter Pringsheim, a pioneer in luminescence. This period in Berlin was intellectually formative; Turner was immersed in a culture of rigorous experimental physics just as the world was beginning to understand the wave properties of light in thin layers.

Upon returning to the United States, Turner joined the faculty at the Massachusetts Institute of Technology (MIT) as an instructor. However, his most prolific years began in 1939 when he joined Bausch & Lomb in Rochester, New York. He served as the head of their Glass Physics and Thin Films Department for over three decades.

In 1971, rather than retiring, Turner moved to the University of Arizona, joining the newly established Optical Sciences Center (OSC) as a Professor of Optical Sciences. He remained active in research and mentorship in Tucson until his death in 1996.

2. Major Contributions: Controlling the Behavior of Light

Turner’s work focused on "thin-film interference"—the phenomenon where light waves reflecting off the top and bottom surfaces of a microscopic layer of material either cancel each other out or reinforce one another.

Anti-Reflection (AR) Coatings: Turner was instrumental in the commercial development of Magnesium Fluoride ($MgF_2$) coatings. By applying a layer exactly one-quarter the wavelength of light in thickness, he showed how to virtually eliminate surface reflections. This revolutionized photography and cinematography, allowing for complex multi-element lenses that didn't lose light to internal glare.
Cold Mirrors and Heat Reflectors: He developed dichroic filters, commonly known as "cold mirrors." These reflect visible light while allowing infrared (heat) to pass through the back of the mirror. This technology became essential for movie projectors (to prevent film from melting) and dental lamps (to keep the light cool for the patient).
Interference Filters: Turner refined the design of narrow-band interference filters (Fabry-Pérot type), which allow only a very specific color of light to pass through. These are now vital in everything from telecommunications to medical diagnostics.
The "Turner Filter": He is often credited with the development of frustrated total internal reflection (FTIR) filters, which use the "tunneling" of light waves across narrow gaps to create highly precise optical switches and filters.

3. Notable Publications

Turner was more than an industrial researcher; he was a prolific communicator of science. His work often bridged the gap between theoretical physics and practical engineering.

"Antireflection Coatings on Glass" (1946): Published in the Journal of the Optical Society of America (JOSA), this paper laid out the mathematical and physical foundations for the coatings used in modern lenses.
"Methods of Deposition of Dielectric Thin Films" (1950s): A series of technical papers that standardized how materials like zinc sulfide and magnesium fluoride were evaporated in vacuum chambers.
"Thin Films in Optics": While not a single book, his contributions to various handbooks and encyclopedias during the 1960s served as the "bible" for the first generation of thin-film engineers.

4. Awards & Recognition

Turner’s peers recognized him as the dean of the thin-film community. His accolades include:

Frederic Ives Medal (1971): The highest award given by the Optical Society of America (OSA) for overall distinction in optics.
C.E.K. Mees Medal (1959): Awarded for his contributions to the development of optical coatings and their application to photography.
President of the Optical Society of America (1968): He served as the leader of the world’s premier professional organization for optical scientists.
Honorary Doctorate: Awarded by the University of Arizona for his role in building the school into a global powerhouse for optical research.

5. Impact & Legacy

Turner’s legacy is embedded in the infrastructure of the modern world. Before his work, a camera with ten lens elements would lose nearly 50% of incoming light to reflections; Turner’s coatings reduced that loss to less than 1%.

In the realm of Space Exploration, his work on thermal control coatings allowed early satellites to survive the extreme temperature swings of orbit. In Academic Circles, his move to the University of Arizona helped transform the Optical Sciences Center into one of the top three optics programs in the United States. He mentored a generation of "thin-film wizards" who went on to lead companies like OCLI (Optical Coating Laboratory, Inc.) and Schott Glass.

6. Collaborations

Turner was a collaborative bridge-builder between industry and academia.

Bausch & Lomb Research Team: He led a group of scientists who turned vacuum deposition from a temperamental art into a repeatable industrial science.
Aden Meinel: Turner worked closely with Meinel, the founding director of the Optical Sciences Center at Arizona, to integrate industrial thin-film expertise into the university's curriculum.
Philip Baumeister: A frequent collaborator and fellow pioneer, with whom Turner shared many discussions on the computational methods for multi-layer film design.

7. Lesser-Known Facts

WWII Secret Efforts: During World War II, Turner’s work at Bausch & Lomb was considered a high-priority military asset. His AR coatings were applied to binoculars, rangefinders, and submarine periscopes, giving Allied observers a significant advantage in low-light conditions.
The "Human Computer" Era: Before the advent of digital computers, Turner performed the incredibly complex calculations for multi-layer coatings (which involve complex matrix algebra) by hand or using mechanical calculators—a feat of mathematical endurance.
Late-Blooming Academic: Most scholars establish their academic reputation in their 30s. Turner began his most influential period of teaching and university research in his 60s, proving that industrial expertise is a vital component of academic evolution.

Arthur F. Turner remains a towering figure in physics—a man who looked at a simple piece of glass and saw a canvas for the manipulation of light at the atomic scale.