James P. Wolfe, professor of physics emeritus, 78, died Tuesday, February 1, 2022 in Urbana.

Jim was born in San Antonio, TX on July 16, 1943. The son of Elizabeth and John Wolfe, a colonel in the US military, Jim finished high school at Colegio San Carlos in Puerto Rico, where his family was stationed at the time. It was there that he met Kathy Boyd at the age of 16. They were married in 1966 and have celebrated 55 loving years together.

Jim spent his entire career at the University of Illinois, retiring in 2006 after 30 years in Urbana. He was a principal investigator in the Frederick Seitz Materials Research Laboratory (MRL), where he concentrated on the physics of excitonic matter and phonons in solids. Phonons are vibrations of atoms or molecules in the crystal structure of materials that propagate as sound or heat, depending on the frequency of the vibrations, as they pass through the material.

Jim received his bachelor's and doctoral degrees in physics from the University of California, Berkeley. He remained at Berkeley as an assistant research physicist, and with Carson Jeffries' group, he applied optical and microwave techniques to the newly discovered phenomena of electron-hole droplets in germanium. Using infrared imaging, they took the first photo of an electron-hole droplet. He joined the Department of Physics at Illinois as an assistant professor in 1976. He rose rapidly through the faculty ranks, being promoted to professor in 1981.

Best known for developing novel imaging techniques to study excitonic matter and phonon propagation at ultracold temperatures, Jim's group created time-resolved luminescence imaging techniques to determine the spatial distribution and mobilities of electron-hole droplets and excitons in bulk semiconductors, such as silicon, germanium, and copper oxide. Jim's group combined picosecond laser spectroscopy and micro-imaging techniques to measure the in-plane motion of photoexcited carriers in semiconductor quantum wells. Since its introduction in 1978, "phonon imaging" has contributed graphically and quantitatively to far-reaching topics in phonon physics. Utilizing tiny superconducting detectors and laser-scanned heat sources, phonon imaging has elucidated diverse physical phenomena—phonon focusing, lattice dynamics, and phonon scattering at interfaces, superlattices, and defects.

Jim directed multi-investigator projects for the National Science Foundation and the U.S. Department of Energy at the MRL. Between 1999 and 2002, he served as the Department of Physics' associate head for graduate programs, one of the largest in the nation. He also served on several high-level campus administrative committees over the years and supervised the thesis research of 25 doctoral students during the course of his prolific career. A dedicated and gifted teacher, Jim developed an introductory textbook after his retirement, "Elements of Thermal Physics," that is used by approximately 1000 undergraduate engineering students at Illinois every year. His research textbook, "Phonon Imaging," has become a staple for graduate students and researchers alike.

In 2004, Jim was awarded the Frank Isakson Prize of the American Physical Society "for contributions to the fundamental understanding of excitonic matter in semiconductors, including its propagation, made possible by pioneering development of imaging techniques that lend graphic insights to electronic and vibrational processes in solids." In 2010, Jim received the Paul G. Klemens Award of the International Conference on Phonon Scattering in Condensed Matter for his investigations of a phonon "wind" and his groundbreaking contributions to the phonon physics involved in dark matter detection. He received a U.S. Senior Scientist Award in 1988 from the Alexander von Humboldt Foundation (Germany), and a Japan Society for the Promotion of Science Fellowship in 1991. He was elected a Fellow of the American Physical Society in 1980 and a Beckman Fellow of the University of Illinois Center for Advanced Study in 1982.

Jim's research on phonon physics never waned, however he decided to retire and enjoy time with his loving wife and family, to travel, and to pursue his many hobbies. His science was an artistic process, and he was also an avid photographer who captured stunning scenes of family, travel and nature. His love of music led him to play the bongos, cello and more recently the guitar. He was an audiophile who began by building Bose speakers from a kit.  He was always seeking the perfect stereo system. Jim loved sports, and got tremendous joy in playing tennis and golf.  He was always up for new adventures, like water skiing, scuba, and snorkeling.

Jim never ran into a single stranger without starting up a conversation. He had a fearless love of mankind and always remained on the bright side of life. A healthy balance of work and family, you would catch him on the road with PHONON license plates (of course). Jim adored his wife, Kathy, who survives him. They had three daughters who also survive: Lisa Wolfe (David Hayes) of Pomona, N.Y.; Julie Wolfe (Alan Phenix) of Los Angeles CA; and Linda Wolfe (Brad Stine) of Oak Park, IL. His five wonderful grandchildren are Anne and Beth Stine, Corbin Phenix, and Ben and James Hayes. Also surviving are his sisters Pat Wolters (Bob) and Lynn Murray (Vince) along with many nieces and nephews.

Jim remained cheerful and valiant while battling Alzheimer's the last decade of his life.  He passed away peacefully with family at his side. A family memorial is planned for a later date, and in lieu of flowers, contributions may be made to the Alzheimer's Association. Condolences may be offered at rennerwikoffchapel.com.