TY - GEN

T1 - Mode dynamics during transition into Kerr self-cleaning regime for laser beams propagated in a multimode GRIN fiber

AU - Gervaziev, Mikhail D.

AU - Zhdanov, Innokentiy

AU - Kharenko, Denis S.

AU - Podivilov, Evgeniy V.

AU - Babin, Sergey A.

AU - Wabnitz, Stefan

N1 - Funding Information: This work was supported by the Ministry of Science and Higher Education of the Russian Federation (14.Y26.31.0017), by RFBR (Grant No. 20-32-90132) and the EU Horizon2020 ERC (Grants 874596 and 740355). Publisher Copyright: © 2021 IEEE.

PY - 2021/6

Y1 - 2021/6

N2 - For a long time, interest in multimode (MM) optical fibers has remained limited, owing to the poor quality of laser beams emerging at their output. A typical indicator of beam quality is inversely proportional to the number of excited modes. However, recent intensive research of nonlinear propagation effects, involving high-power laser beams in MM graded-index (GRIN) fibers, has led to the discovery of previously unexpected phenomena, such as the Kerr-activated self-cleaning of a beam [1]. The manifestation of self-cleaning is that most of the beam energy flows into the fundamental mode of the fiber. This process is accompanied by a redistribution of energy towards higher-order modes [2]. Increasing the fundamental mode energy leads to improving the output beam quality. The standard method to determine the beam quality is to measure the M2-parameter (m-squared). This parameter measures the divergence of the beam with respect to the Gaussian beam. However, since self-cleaning involves a nonlinear redistribution of energy carried by a large number of fiber modes, this approach is not entirely correct, and a full mode decomposition (MD) of the output beam appears to be a much more informative method.

AB - For a long time, interest in multimode (MM) optical fibers has remained limited, owing to the poor quality of laser beams emerging at their output. A typical indicator of beam quality is inversely proportional to the number of excited modes. However, recent intensive research of nonlinear propagation effects, involving high-power laser beams in MM graded-index (GRIN) fibers, has led to the discovery of previously unexpected phenomena, such as the Kerr-activated self-cleaning of a beam [1]. The manifestation of self-cleaning is that most of the beam energy flows into the fundamental mode of the fiber. This process is accompanied by a redistribution of energy towards higher-order modes [2]. Increasing the fundamental mode energy leads to improving the output beam quality. The standard method to determine the beam quality is to measure the M2-parameter (m-squared). This parameter measures the divergence of the beam with respect to the Gaussian beam. However, since self-cleaning involves a nonlinear redistribution of energy carried by a large number of fiber modes, this approach is not entirely correct, and a full mode decomposition (MD) of the output beam appears to be a much more informative method.

UR - http://www.scopus.com/inward/record.url?scp=85117593247&partnerID=8YFLogxK

U2 - 10.1109/CLEO/Europe-EQEC52157.2021.9542580

DO - 10.1109/CLEO/Europe-EQEC52157.2021.9542580

M3 - Conference contribution

AN - SCOPUS:85117593247

T3 - 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021

BT - 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021

PB - Institute of Electrical and Electronics Engineers Inc.

T2 - 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021

Y2 - 21 June 2021 through 25 June 2021

ER -