MODE DECOMPOSITION METHOD FOR INVESTIGATING THE NONLINEAR DYNAMICS OF A MULTIMODE BEAM
M. Gervaziev1,2, M. Ferraro3, E. V. Podivilov1,2, F. Mangini3, O.S. Sidelnikov2, D.S. Kharenko1,2, M. Zitteli 3, M.P. Fedoruk2, S.A. Babin1,2, S. Wabnitz2,3
1Institute of Automation and Electrometry SB RAS, Novosibirsk, Russia
gervaziev.m@gmail.com
2Novosibirsk State University, Novosibirsk, Russia
podivilov@iae.nsk.su
3Sapienza University of Rome, Rome, Italy
mario.ferraro@uniroma1.it
Ключевые слова: Mode decomposition, thermalization, multimode fiber
Страницы: 58-69
Аннотация
We overview our recent experimental studies on the nonlinear spatial reshaping of multimode beams at the output of multimode optical fibers. We use a holographic mode decomposition technique, which permits to reveal the variation of the spatial mode composition at the fiber output, as determined by either conservative (the Kerr effect) or dissipative (Raman scattering) nonlinear processes. For the first case, we consider the effect of spatial beam self-cleaning, and we compare experimental mode decompositions with predictions based on the thermodynamic theory, including the case of beams carrying nozero orbital angular momentum. For the second case, we analyze the beam mode content at the output of a Raman laser based on a graded index multimode fiber.
DOI: 10.15372/AUT20230106
EDN: MSYSQE
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