• Laser & Optoelectronics Progress
  • Vol. 61, Issue 11, 1116010 (2024)
Yi Ni1,*, Yu Lin1,2, Yin Xu1,2, and Yedeng Fei1,2
Author Affiliations
  • 1School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China
  • 2Institute of Advanced Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
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    DOI: 10.3788/LOP232624 Cite this Article Set citation alerts
    Yi Ni, Yu Lin, Yin Xu, Yedeng Fei. High-Efficiency, Large Bandwidth Grating Coupler Based on Lithium Niobate Thin Film (Invited)[J]. Laser & Optoelectronics Progress, 2024, 61(11): 1116010 Copy Citation Text show less
    Schematic diagram of overall structure of a two-dimensional grating coupler. (a) Overall structure diagram; (b) side view structure diagram; (c) schematic diagram of top triangular silicon layer structure
    Fig. 1. Schematic diagram of overall structure of a two-dimensional grating coupler. (a) Overall structure diagram; (b) side view structure diagram; (c) schematic diagram of top triangular silicon layer structure
    Relationship between longitudinal period of silicon grating and coupling efficiency and bandwidth of device. (a) Coupling efficiency and 1 dB bandwidth of silicon grating with different longitudinal periods at wavelength of 1550 nm; (b) coupling efficiency as a function of wavelength at different longitudinal periods
    Fig. 2. Relationship between longitudinal period of silicon grating and coupling efficiency and bandwidth of device. (a) Coupling efficiency and 1 dB bandwidth of silicon grating with different longitudinal periods at wavelength of 1550 nm; (b) coupling efficiency as a function of wavelength at different longitudinal periods
    Effect of LNTF thickness on device coupling efficiency. (a) Coupling efficiency corresponding to LN thin films of different thicknesses; (b) coupling efficiency as a function of wavelength at different LNTF thicknesses
    Fig. 3. Effect of LNTF thickness on device coupling efficiency. (a) Coupling efficiency corresponding to LN thin films of different thicknesses; (b) coupling efficiency as a function of wavelength at different LNTF thicknesses
    Coupling efficiency corresponding to different fiber tilt angles in same band and light field diagram of coupler coupling upward when angle of inclination is 8°. (a) Coupling efficiency corresponding to different fiber tilt angles at wavelength 1550 nm; (b) electric field distribution Ey of the grating couplerwhen angle of inclination is 8°
    Fig. 4. Coupling efficiency corresponding to different fiber tilt angles in same band and light field diagram of coupler coupling upward when angle of inclination is 8°. (a) Coupling efficiency corresponding to different fiber tilt angles at wavelength 1550 nm; (b) electric field distribution Ey of the grating couplerwhen angle of inclination is 8°
    Coupling efficiency and 1 dB bandwidth corresponding to optimal solution of various parameters
    Fig. 5. Coupling efficiency and 1 dB bandwidth corresponding to optimal solution of various parameters
    TypeCoupling efficiency /%Bandwidth /nmReference
    LN-on-SiO2(chirp grating)43.748(-3 dB)6
    LN-on-SiO2integrated coupler14.580(-3 dB)23
    LN-on-SiO2metal reflector45.730(-1 dB)22
    Si3N4-on-SOI33.5113(-3 dB)7
    Si-on-LN(polarization independent50.186(-3 dB)26
    A-Si-on-LN49.455(-1 dB)19
    Si-on-LN61.1102(-1 dB)This work
    Table 1. Performance comparison of two dimensional grating couplers on lithium niobate waveguide platform
    Yi Ni, Yu Lin, Yin Xu, Yedeng Fei. High-Efficiency, Large Bandwidth Grating Coupler Based on Lithium Niobate Thin Film (Invited)[J]. Laser & Optoelectronics Progress, 2024, 61(11): 1116010
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