Pioneering UCSB Laser Expert John Bowers Is Set to Retire
Wednesday, June 11, 2025
by James Badham
After thirty-eight years as a professor at UC Santa Barbara, John Bowers is retiring. Bowers, a pioneer in lasers, photonics, and photonic integrated circuits (PICs), has served as director of the Institute for Energy Efficiency (IEE) at UCSB since it was founded in 2008 and is also a Distinguished Professor in the Departments of Electrical & Computer Engineering, Materials, and Technology Management at UCSB.
As an emeritus professor, Bowers will have far fewer administrative responsibilities and will not teach, but don’t expect to see less of the Fred Kavli Chair in Nanotechnology around campus, for in his view, much remains for him to do.
“I plan to continue to do research, particularly in silicon photonics,” says Bowers, who served as deputy director of the American Institute of Manufacturing of Integrated Photonics, which is focused on driving low-cost, high-volume CMOS processing of PICs. “The problem of energy consumption and its impact on climate change is more important now than ever, and I can't abandon that research. I want to continue working with small companies and helping the Technology Management Department at UCSB continue with its important mission. While my group is getting smaller, I will still have a few graduate students and postdocs, and to mentor and meet with students as needed.”
Bowers will be succeeded as IEE director by his longtime colleague, materials professor Steven DenBaars, who is also co-director of the Solid State Lighting and Energy Electronics Center (SSLEEC) at UCSB.
“The IEE has become one of the most important interdisciplinary research centers at UCSB, focusing on energy-efficient technologies that have real-world impact, from data centers to lighting, computing, and sustainable manufacturing,” DenBaars said. “Under John’s leadership, it has grown significantly in scope and reputation, bringing together faculty from engineering, physics, and materials science to tackle energy challenges. John deserves tremendous credit for fostering a collaborative environment and for championing industry engagement, which has amplified our research impact.”
“John Bowers is an academic Renaissance man: a stellar academic researcher, a successful serial entrepreneur and an innovative academic curriculum and institutional leader, COE dean, Umesh Mishra. “In spite of his commitments, John is also very kind and generous with his time — a role model for students and colleagues alike. His impact on UCSB is immeasurable. I want to be like him when I grow up.”
Bowers earned his PhD (1980) and his MS (1976) in applied physics from Stanford University, where he also did his postdoctoral work, and a BS in physics from the University of Minnesota.
He arrived at UCSB as a professor in the Electrical & Computer Engineering Department in 1987, after several years at Bell Laboratories, a time when lasers were, practically speaking, in their infancy. Conceived of in the late 1950s, the first functional semiconductor laser was built in 1962. Today, thanks to contributions from researchers like Bowers, chip-scale lasers enable every aspect of modern fiber optic communications. He has made seminal contributions to technologies that, together, have increased data rates in fiber-optic systems more than a thousand fold in the forty years since they began to find wide application.
Discussing the three most important innovations during his career, Bowers says, “One is the development of silicon PICs. During my first fifteen years at UCSB, I worked on gallium arsenide (GaAs) and indium phosphate (InP) PICs, and then started to work on silicon PICs. The field has exploded, and every major data communications company now has a large research effort in this area. Part of my work on silicon PICs has involved laser integration into the PIC, which is easy for GaAs and InP substrates, but difficult for silicon. The heterogeneous bonding approach to laser integration on silicon [developed by Bowers and his former graduate students Alex Fang and Hyundai Park] has become the winning solution to this problem, has since been commercialized by Intel, Juniper, Nexus Photonics, Quintessent, and others. The third innovation is quantum-dot lasers, which have led to important scientific results, including reflection insensitivity, narrow linewidth, and improvements in reliability.”
“It’s truly an honor to follow in John’s footsteps. He is a world leader in silicon photonics, and his contributions to integrating photonic devices with silicon-based platforms have been truly transformational,” DenBaars said. “His work enabled scalable, low-power optical communication for data centers and advanced computing systems. At UCSB, he built a globally recognized program that continues to lead in the development of high-performance photonic integrated circuits.
Speaking about DenBaars succeeding him as IEE director, Bowers said, “Steve has been a key member of IEE since its inception. His research focus has been more-efficient lighting, and he and [Nobel Laureate and SSLEEC director] Shuji Nakamura have been highly innovative and extremely successful in leading worldwide research in this area. I have no doubt that in his most-capable hands, the IEE will continue in and expand its role as a world-leading institution focused on achieving an ever-more energy-efficient future.
“I’ve had the pleasure of collaborating with John since the early 1990s in areas including InP and GaN-based lasers, and our research paths have often intersected,” he continued. “His vision and technical contributions continue to shape the field. I enthusiastically assume the role of IEE director and look forward to building on the strong foundation he laid and to further position the institute at the forefront of energy innovation.”
The focus on energy efficiency that has always stood at the heart of Bowers’s research is reflected in his long-term leadership of the IEE, with its mission of reducing the demand for energy and, consequently, the consumption of energy resources and the production of greenhouse gasses, along with their impact on climate change and sustainability.
IEE celebrated its fifteenth anniversary in 2023 with a symposium highlighting some of the major achievements of the more than one hundred IEE-affiliated researchers from within and beyond the COE who have worked with the institute so far, focusing on three main areas of research: Computing and Communications, Food Energy Water, and Smart Societal Infrastructure. Looking back, Bowers notes four achievements that stand out in the relatively short but powerfully impactful history of IEE.
“First,” he says, “is the progress in AI enabled by William Wang and others in the Computer Science Department. Second is the progress in photonic interconnects for data centers and AI, which address a very important problem and one that probably none of us envisioned, which is the huge recent growth in AI and data centers, and the consequent need for more efficient data centers, many of which are now using the silicon photonic interconnect technology we have developed. Third is the progress in smart agriculture, which is being led by computer science professors Chandra Krintz and Rich Wolski and is being commercialized by IEE industrial partner Agmonitor. Finally, the progress in efficient GaN [gallium nitride] lasers and LEDs, led by Steve and Shuji, and the huge advances in power and efficiency, particularly in blue and UV emission, with extension into the green gap that their work has enabled.”
As Bowers’s successor, DenBaars intends mainly to hold steady to the IEE’s course. “My vision as the new director of the Institute for Energy Efficiency is to expand and deepen our interdisciplinary impact by building on several strategic research initiatives,” DenBaars said. “We will continue to focus on creating energy-efficient data centers and utilizing next-generation photonic and electronic switching solutions to meet the exponential energy demands of AI and cloud computing. In parallel, we aim to advance breakthroughs in quantum technologies to unlock fundamentally new mechanisms for computing and energy efficiency. Our efforts in net-zero building and data-center infrastructure will help shape sustainable, smart environments by integrating advanced control systems and dynamic modeling. To enable scalable clean energy storage, we will support efficient battery development, targeting safe solid-state technologies with high energy density. Finally, our commitment to global sustainability includes advancing ag-tech for climate-resilient food systems, and using sensing, automation, and AI to enhance agricultural productivity. Together, these initiatives position IEE at the nexus of scientific innovation and real-world impact.”
For Bowers, the work of saving energy extends well beyond what might be considered “first-world” concerns. For example, collaborative research on more-efficient light emitters, solar cells, and batteries has had a major impact, especially on people in the developing world who lack access to electricity, because using a solar-powered light to read at night is far cheaper and healthier than burning candles, kerosene, or wood. Bowers formed a nonprofit, Unite to Light, with the motto, “Fighting inequity one light at a time,” to make this solar-charged LED lighting technology accessible to the developing world. Since it was founded in 2010, the nonprofit has distributed nearly three hundred thousand lights in eighty nations around the world, which are estimated to have saved $36 million in energy costs and avoided the release of 19 million metric tons of CO2 emissions. “Most importantly,” Bowers notes, “the graduation rate of high school students rises by thirty percent when students without electricity at home are given a light.”
Bowers’s “numbers” are beyond impressive. He has edited two books, published sixteen book chapters, nine-hundred journal papers, and thirteen hundred conference papers, and mentored eighty-five doctoral students. He holds seventy-three patents, and, as a researcher who has a strong entrepreneurial streak and is committed to commercializing technological advances, has co-founded six companies with his students over a decade: Terabit Technology (acquired by Ciena), Aerius Photonics (acquired by FLIR, now Teledyne FLIR), Aurrion (acquired by Juniper), Calient Networks, Nexus Photonics, and Quintessent.
Keenly aware of the need to sow the seeds to ensure that the COE remains a top engineering program, and of the importance of entrepreneurial ventures to make it possible for technology to improve life, Bowers taught classes in entrepreneurship at UCSB for more than twenty years and started the Center for Entrepreneurship and Engineering Management (CEEM) at UCSB, which grew into the Technology Management Department at UCSB. It now offers PhDs, a Master of Technology Management, and Certificates of Technology Management.
Such accomplishments do not occur in isolation, Bowers notes, saying, “I am very grateful for the support of so many UCSB Trustees, which has enabled many new research programs, particularly for new, young faculty. Of course, two Trustees in particular, Jeff Henley and Shawn Byers, stepped up with major gifts to enable a new building, Henley Hall, to house the IEE, which has greatly benefited our research.”
A Clarivate Highly Cited Researcher, Bowers is a member of the National Academy of Engineering, a fellow of the Institute for Electrical and Electronics Engineers (IEEE), the Optical Society of America (OSA), the American Physical Society, and the American Association for the Advancement of Science (AAAS). He has received the IEEE Nishizawa Medal, the IEEE Photonics Award, the OSA’s Tyndall Award and its Holonyak Prize, the IEEE LEOS William Streifer Award, and the South Coast Business and Technology Pioneer and Entrepreneur of the Year Awards. He was elected a member of the National Academy of Engineering in 2005.