Refractive index profile tailoring of multimode optical fibers for the spatial and spectral shaping of parametric sidebands
Authors: Krupa K., Couderc V., Tonello A., Modotto D., Barthelemy A., Millot G., Wabnitz S.
Autors Affiliation: Univ Bourgogne Franche Comte, ICB, UMR CNRS 6303, 9 Av A Savary, F-21078 Dijon, France; Univ Brescia, Dipartimento Ingn Informaz, Via Branze 38, I-25123 Brescia, Italy; Univ Limoges, XLIM, UMR CNRS 7252, 123 Av A Thomas, F-87060 Limoges, France; Sapienza Univ Roma, Dipartimento Ingn Informaz Elettron & Telecomunic, Via Eudossiana 18, I-00184 Rome, Italy; CNR, INO, Via Campi Flegrei 34, I-80078 Pozzuoli, NA, Italy
Abstract: In this paper, we introduce the concept of spatial and spectral control of nonlinear parametric sidebands in multimode optical fibers by tailoring their linear refractive index profile. In all cases, the pump experiences Kerr self-cleaning, leading to a bell-shaped beam profile. Geometric parametric instability, owing to quasi-phase matching from the dynamic grating generated via the Kerr effect by pump self-imaging, leads to frequency multicasting of beam self-cleaning across a wideband array of sidebands. Our experiments show that introducing a Gaussian dip into the refractive index profile of a graded index fiber permits us to dramatically change the spatial content of spectral sidebands into higher-order modes. This is due to the breaking of the oscillation synchronism among low-order and higher-order modes. Hence, the inter-modal four-wave mixing approach should be used to describe the sideband generation mechanism. Observations agree well with theoretical predictions based on a perturbative analysis and with full numerical solutions of the (3+1)D nonlinear Schrodinger equation. (C) 2019 Optical Society of America
Journal/Review: JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B: OPTICAL PHYSICS
Volume: 36 (4) Pages from: 1117 to: 1126
KeyWords: PROPAGATION CHARACTERISTICS; BEAM; INSTABILITYDOI: 10.1364/JOSAB.36.001117Citations: 3data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-07-05References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here