• Chinese Optics Letters
  • Vol. 18, Issue 7, 073601 (2020)
Weiyi Shi, Weimin Deng, Weinan Liu, Zepeng Zhuang, Zhibin Fan, and Jianwen Dong*
Author Affiliations
  • School of Physics & State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
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    Abstract

    In this Letter, we propose a metagrating consisting of simple rectangular bars for nearly unity anomalous diffraction with a large deflection angle. The analysis performed by the scattering-matrix method shows that such exceptional beam steering derives from the couplings of the two lowest propagation waveguide-array-modes and their constructive interferences. The tolerance of the incident angle for a high diffraction efficiency (e.g., >90%) is within a range of 33°. We also discuss that such an advantage still exists after considering a reasonable loss and dispersion. We envision that the proposed strategy may have wide use in the field of high-performance wavefront-shaping applications.
    1nbar2ka,mks,m[1+e2ikx0Λ2cos(ks,ms)cos(ka,ma)eikx0Λ]+sin(ks,ms)sin(ka,ma)(ka,m2+1nbar2ks,m2)eikx0Λ=0.(1)

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    βm2=(2πλ)2ka,m2=(nbar2πλ)2ks,m2.(2)

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    [rA(z=0)]=[ρττρ][incB(z=0)].(3)

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    [tB(z=h)]=[τρρτ][A(z=h)0].(4)

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    t=τ·A(z=h).(5)

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    Tn=|t(n)|2γnγ0.(6)

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    t(1)=τ10A0(z=h)+τ11A1(z=h)+,(7)

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    t(0)=τ00A0(z=h)+τ01A1(z=h)+.(8)

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    Copy Citation Text
    Weiyi Shi, Weimin Deng, Weinan Liu, Zepeng Zhuang, Zhibin Fan, Jianwen Dong. Rectangular dielectric metagrating for high-efficiency diffraction with large-angle deflection[J]. Chinese Optics Letters, 2020, 18(7): 073601
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    Category: Nanophotonics
    Received: Mar. 16, 2020
    Accepted: Apr. 30, 2020
    Posted: Jun. 15, 2020
    Published Online: Jun. 16, 2020
    The Author Email: Jianwen Dong (dongjwen@mail.sysu.edu.cn)