eprintid: 10064274 rev_number: 17 eprint_status: archive userid: 608 dir: disk0/10/06/42/74 datestamp: 2018-12-14 13:07:09 lastmod: 2021-12-18 23:59:27 status_changed: 2018-12-14 13:07:09 type: article metadata_visibility: show creators_name: You, JW creators_name: Threlfall, E creators_name: Gallagher, DFG creators_name: Panoiu, NC title: Computational analysis of dispersive and nonlinear 2D materials by using a GS-FDTD method ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F46 note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: In this paper, we propose a novel numerical method for modeling nanostructures containing dispersive and nonlinear two-dimensional (2D) materials, by incorporating a nonlinear generalized source (GS) into the finite-difference time-domain (FDTD) method. Starting from the expressions of nonlinear currents characterizing nonlinear processes in 2D materials, such as second- and third-harmonic generation, we prove that the nonlinear response of such nanostructures can be rigorously determined using two linear simulations. In the first simulation, one computes the linear response of the system upon its excitation by a pulsed incoming wave, whereas in the second one the system is excited by a nonlinear GS, which is determined by the linear near-field calculated in the first linear simulation. This new method is particularly suitable for the analysis of dispersive and nonlinear 2D materials, such as graphene and transition-metal dichalcogenides, chiefly because, unlike the case of most alternative approaches, it does not require the thickness of the 2D material. To investigate the accuracy of the proposed GS-FDTD method and illustrate its versatility, the linear and nonlinear responses of graphene gratings have been calculated and compared to results obtained using alternative methods. Importantly, the proposed GS-FDTD can be extended to three-dimensional bulk nonlinearities, rendering it a powerful tool for the design and analysis of more complicated nanodevices. date: 2018-11 date_type: published publisher: OPTICAL SOC AMER official_url: https://doi.org/10.1364/JOSAB.35.002754 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1602865 doi: 10.1364/JOSAB.35.002754 language_elements: English lyricists_name: Panoiu, Nicolae-Coriolan lyricists_name: You, Jianwei lyricists_id: NPANO59 lyricists_id: JWYOU76 actors_name: Novi, Maya actors_id: MNOVI52 actors_role: owner full_text_status: public publication: Journal of the Optical Society of America B volume: 35 number: 11 pagerange: 2754-2763 pages: 10 issn: 1520-8540 citation: You, JW; Threlfall, E; Gallagher, DFG; Panoiu, NC; (2018) Computational analysis of dispersive and nonlinear 2D materials by using a GS-FDTD method. Journal of the Optical Society of America B , 35 (11) pp. 2754-2763. 10.1364/JOSAB.35.002754 <https://doi.org/10.1364/JOSAB.35.002754>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10064274/1/You_GS_FDTD_Revised.pdf