Experimental observation of Kerr beam self-cleaning in graded-index multimode fiber from higher-order mode to fundamental mode

Mondal, P and Varshney, SK (2021) Experimental observation of Kerr beam self-cleaning in graded-index multimode fiber from higher-order mode to fundamental mode. In: Optical Fiber Technology, 65 .

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Abstract

We experimentally demonstrate Kerr beam self-cleaning in 90 m long standard graded-index (GRIN) multimode fiber (MMF) for normal and oblique launching conditions. Sub-nanosecond pump pulses are launched in the normal dispersion regime of the GRIN MMF. We measure the simultaneous evolution of the near field modal profile and the output spectrum for various pump powers under different launching conditions. Experimental findings establish that the nonlinear coupling among the guided modes leads to reshaping the output speckle pattern into a bell shape (LP01) or higher-order (LP11 and LP21) spatially clean beam profile at very low input pump powers, whereas the spectral domain exhibits generation of modulation instability peaks. Threshold power for the self-cleaning process increases effectively for higher-order modes. © 2021 Elsevier Inc.

Item Type:	Journal Article
Publication:	Optical Fiber Technology
Publisher:	Academic Press Inc.
Additional Information:	The copyright for this article belongs to Academic Press Inc.
Keywords:	Multimode fibers; Optical pumping; Pumps; Speckle; Ultrafast lasers, Fundamental modes; Graded-Index Multimode fibers; Higher-order modes; Modulation instabilities; Multi-mode fibers (MMF); Nonlinear coupling; Normal dispersion; Self-cleaning process, Cleaning
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	24 Aug 2021 06:29
Last Modified:	24 Aug 2021 06:29
URI:	http://eprints.iisc.ac.in/id/eprint/69230

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