LPHYS'26. Plenary Speakers:
High-power Single-Frequency Multimode Fiber Laser Amplifiers
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Hui Cao
Department of Applied Physics, Yale University, New Haven, CT, USA
hui.cao@yale.edu
Biography:
Hui Cao is the John C. Malone Professor of Applied Physics, a Professor of Physics, and a Professor of Electrical Engineering at Yale University. She received her Ph.D. degree in Applied Physics from Stanford University in 1997. Prior to joining the Yale faculty in 2008, she was on the faculty of Northwestern University for ten years.
Her technical interests and activities are in the areas of mesoscopic physics, complex photonic materials and devices, nanophotonics, and biophotonics. Cao is a Fellow of IEEE, AAAS, APS, and OSA, and an elected member of the National Academy of Sciences and the American Academy of Arts and Sciences.
Abstract:
High-power fibre lasers are powerful tools used in science, industry, and defence. A major roadblock for further power scaling of single-frequency fibre laser amplifiers is stimulated Brillouin scattering. Efforts have been made to mitigate this nonlinear process, but these were mostly limited to single-mode or few-mode fibre amplifiers, which have good beam quality.
Recently, we explored a highly multimode fibre amplifier in which stimulated Brillouin scattering was greatly suppressed due to a reduction of light intensity in a large fibre core and a broadening of the Brillouin scattering spectrum by multimode excitation. By applying a spatial wavefront-shaping technique to the input light of a nonlinear amplifier, the output beam was focused to a diffraction-limited spot.
Our multimode fibre amplifier can operate at high power with high efficiency and narrow linewidth, which ensures high coherence. Optical wavefront shaping enables coherent control of multimode laser amplification, with potential applications in coherent beam combining, large-scale interferometry, and directed energy delivery.
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