Mohammadzahery Z, Jandaghi M, Aghayari E, Nabavi H. Observation of spatial nonlinear self-cleaning in a few-mode step-index fiber for special distributions of initial excited modes.
Sci Rep 2021;
11:24350. [PMID:
34934169 PMCID:
PMC8692529 DOI:
10.1038/s41598-021-03856-x]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/10/2021] [Indexed: 11/09/2022] Open
Abstract
In this paper, we experimentally demonstrate that a nonlinear Kerr effect in suitable coupling conditions can introduce a spatially self-cleaned output beam for a few-mode step-index fiber. The impact of the distribution of the initial excited modes on spatial beam self-cleaning has been demonstrated. It is also shown experimentally that for specific initial conditions, the output spatial pattern of the pulsed laser can be reshaped into the LP11 mode due to nonlinear coupling among the propagating modes. Self-cleaning into LP11 mode required higher input powers with respect to the power threshold for LP01 mode self-cleaning. Our experimental results are in agreement with the results of numerical calculations.
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