Journal of East China Normal University(Natural Science) ›› 2023, Vol. 2023 ›› Issue (4): 127-136.doi: 10.3969/j.issn.1000-5641.2023.04.014

• Physics and Electronics • Previous Articles     Next Articles

Subwavelength lithium niobate film guided mode resonance structure design and second harmonic conversion efficiency optimization

Chunyu CAO1, Minni QU2, Wei XIE1,*()   

  1. 1. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
    2. Center for Advanced Electronic Materials and Devices, School of Electronics Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2022-05-10 Online:2023-07-25 Published:2023-07-25
  • Contact: Wei XIE


The optical response characteristics of a subwavelength lithium niobate film guided-mode resonance metasurface were investigated via simulations. The influences of parameters such as the period, filling factor and etching depth of the etched micro–nano structure on the transmission spectrum were examined, and the effects of light sources with different polarization states and incidence angles on the spectral linewidth were imvestigated. Because of the asymmetric grating structure design, the bound states in the continuum (BIC) decay into a quasi-BIC mode with a high Q value (>10 000), and the second harmonic conversion efficiency of the subwavelength lithium niobate film increases by five orders of magnitude as a result of the local field enhancement effect of the bound state. The simulation results show that a high-efficiency conversion of the second harmonic can be realized in the ultraviolet band when the peak power density of the incident fundamental wave is on the order of ~1 GW/cm2, that is, the ultraviolet second harmonic conversion efficiency emitted after a single pass through the subwavelength lithium niobate film is up to 10–3 orders of magnitude. This study affords ideas and design schemes for improving the nonlinear response characteristics of a micro–nano structure and optical table interface system.

Key words: lithium niobate film, optical metasurface, guided mode resonance, second harmonic

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