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21 June 2021

The OSA Foundation, Coherent Inc., Announce the 2021 Recipient of The Bernard J. Couillaud Prize

Postdoctoral Researcher Bowen Li Advances Frequency Comb Technology for Communication, Sensing and Imaging

WASHINGTON – The OSA Foundation (OSAF) and Coherent, Inc., are pleased to announce Bowen Li, a postdoctoral researcher at the University of Colorado, Boulder, USA, as the 2021 Bernard J. Couillaud Prize winner. 

The prize was presented to Li during the all-virtual Laser World of Photonics plenary session on Monday, 21 June 2021. The Couillaud Prize is a merit-based award of USD 25,500, to support early-career OSA members with an area of focus on ultrafast photonics research and application development.

“Ultrafast photonics addresses a growing number of important applications in scientific research and industry. As such, it is one of the core laser technologies at Coherent,” commented Chris Dorman, Sr. Vice-President at Coherent. “In its first three years, the prize has been awarded to researchers working in diverse fields such as integrated photonics, bio-imaging, and now a novel device with applications to spectroscopy and environmental monitoring.”

Li’s winning proposal focuses on the first counter-propagating all-normal dispersion (CANDi) fiber laser, a next-generation dual-comb laser source that generates two frequency combs with unprecedented pulse energies from a single fiber laser cavity.

“This emerging dual-comb architecture demonstrates the feasibility of bidirectional mode-locking in fiber laser using artificial saturable absorber and all-normal dispersion, against conventional beliefs,” said Li. “Compared to existing dual-comb fiber lasers, it generates orders-of-magnitude-higher pulse energies as well as completely overlapping and flat optical spectra directly from the cavity.”

The CANDi fiber laser is a promising solution for practical dual-comb metrology devices that benefit various applications such as molecular spectroscopy, biochemical imaging and precise laser ranging.

“With the first counter-propagating all-normal dispersion fiber laser, Bowen Li demonstrated that it is possible to break the pulse energy limit,” said Eric Mazur, Chair, OSA Foundation Board of Directors. “This research will spur development of new mode-locked fiber lasers benefiting precision optical metrologies and dual-comb applications. Li’s recognition as the 2021 Couillaud Prize recipient is well-deserved.”

The prize honors the memory and extraordinary contributions of Bernard J. Couillaud, a former President and CEO of Coherent, Inc. (1996-2002) who later served as chair of the board of directors (2002-2007). As a well-known mentor, friend, colleague and pillar of the photonics community, Couillaud is perhaps best-known for his contributions to laser frequency stabilization, known as the Hänsch-Couillaud method.

The 2021 Couillaud Prize was presented, virtually, by Dr. Christoph Dorman OBE on Monday, 21 June. The presentation will be available through recorded archive for on-demand viewing. Visit for registration and access instructions.

About The OSA Foundation

The OSA Foundation is a 501(c)(3) non-profit foundation established by the Optical Society (OSA) in 2002 to carry out charitable activities that support the society’s mission of promoting the generation, application, archiving and worldwide dissemination of knowledge in optics and photonics. The Foundation helps cultivate the next generation of leaders and innovators in the optics and photonics community as they move through advanced degree programs and become active members of research, engineering and business communities around the globe. The Foundation also works to secure OSA Awards and Honors program endowments. For more information, visit

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