Asymmetric nonlinear-mode-conversion in an optical waveguide withPT symmetry

Abstract

Asymmetric mode transformation in waveguide is of great significance for on-chip integrated devices with one-way effect, while it is challenging to achieve asymmetric nonlinear-mode-conversion (NMC) due to the limitations imposed by phase-matching. In this work, we theoretically proposed a new scheme for realizing asymmetric NMC by combining frequency-doubling process and periodic PT symmetric modulation in an optical waveguide. By engineering the one-way momentum from PT symmetric modulation, we have demonstrated the unidirectional conversion from pump to second harmonic with desired guided modes. Our findings offer new opportunities for manipulating nonlinear optical fields with PT symmetry, which could further boost more exploration on on-chip nonlinear devices assisted by non-Hermitian optics.

Graphical abstract

Keywords

nonlinear mode conversion / meta-grating / PT symmetry / optical waveguide

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Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant Nos. 11904169 and 91950106), the Fundamental Research Funds for the Central Universities (Grant No. NE2022007), the Natural Science Foundation of Jiangsu Province (No. BK20190383), Postdoctoral Science Foundation of Jiangsu Province (No. 2020Z224), China Postdoctoral Science Foundation (No. 2020M681576), and the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions.

Disclosures

The authors declare no conflicts of interest.

Data availability

Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.

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