• Acta Physica Sinica
  • Vol. 69, Issue 15, 154206-1 (2020)
Yun-Tian Chen1,2, Jing-Wei Wang1, Wei-Jin Chen1, and Jing Xu1,2,*
Author Affiliations
  • 1School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
  • 2Wuhan National Laboratory of Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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    DOI: 10.7498/aps.69.20200194 Cite this Article
    Yun-Tian Chen, Jing-Wei Wang, Wei-Jin Chen, Jing Xu. Reciprocal waveguide coupled mode theory[J]. Acta Physica Sinica, 2020, 69(15): 154206-1 Copy Citation Text show less
    Symmetry relations between the forward and backward propagating modes: (a) Chiral symmetry; (b) time reversal symmetry; (c) parity symmetry.
    Fig. 1. Symmetry relations between the forward and backward propagating modes: (a) Chiral symmetry; (b) time reversal symmetry; (c) parity symmetry.
    Real part of effective mode indices versus : (a) in core layer 1 and in core layer 2; (b) in core layer 1 and in core layer 2.
    Fig. 2. Real part of effective mode indices versus : (a) in core layer 1 and in core layer 2; (b) in core layer 1 and in core layer 2.
    Real part and imaginary part of effective mode indices versus : (a), (c) Real part of effective mode indices ; (b), (d) imaginary part of effective mode indices .
    Fig. 3. Real part and imaginary part of effective mode indices versus : (a), (c) Real part of effective mode indices ; (b), (d) imaginary part of effective mode indices .
    Anisotropic waveguide: (a) The schematic of elliptical waveguide; (b) the real (red line) and imaginary (black line) part of effective modal indices, calculated from fullwave simulation using finite element method, as a function of ; (c) real part of effective mode indices ; (d) imaginary part of effective mode indices ; (e)−(h) the real/imaginary part ofobtained from fullwave simulation is shown for the modes
    Fig. 4. Anisotropic waveguide: (a) The schematic of elliptical waveguide; (b) the real (red line) and imaginary (black line) part of effective modal indices, calculated from fullwave simulation using finite element method, as a function of ; (c) real part of effective mode indices ; (d) imaginary part of effective mode indices ; (e)−(h) the real/imaginary part of obtained from fullwave simulation is shown for the modes
    $\beta_i$对应的模式 $-\beta_i$对应的模式
    $({\bar{{L}}}, {\bar{{B}}})$$\left[\beta_i, {{\phi}}_i\right]$$\left[-\beta_i, {{\psi}}_i\right]$
    $({\bar{{L}}}^{\rm{a}}, {\bar{{B}}}^{\rm{a}})$$\left[\beta_i, {{\psi}}_i\right]$$\left[-\beta_i, {{\phi}}_i\right]$
    Table 1. Symmetric relation of original field and adjoint field in the reciprocal waveguides with
    对称关系算符对称性关系约束条件
    手征对称${\sigma}$${{{\psi}}}_i({{r}}) = {\bar{\sigma}}{{{\phi}}}_i({{r}})$${{{\varepsilon}}}_{\rm r}^{zt} = {{{\varepsilon}}}_{\rm r}^{tz} = 0$, ${{{\mu}}}_{\rm r}^{zt} = {{{\mu}}}_{\rm r}^{tz} = 0$${\bar{ \chi}} = 0$
    时间反演对称${\cal{T}}$${{{\psi}}}_i({{r}}) = {\bar{\sigma}}({{{\phi}}}_i({{r}}))^*$${\bar{{{\varepsilon}}}}_{\rm r}$, ${\bar{{{\mu}}}}_{\rm r}$${\bar{ \chi}}$是实数
    宇称对称${\cal{P}}$${{{\psi}}}_i({{r}}) = {\bar{\sigma}}{{{\phi}}}_i(-{{r}})$${\bar{{{\varepsilon}}}}_{\rm r}({{r}}) = {\bar{{{\varepsilon}}}}_{\rm r}(-{{r}})$, ${\bar{{{\mu}}}}_{\rm r}({{r}}) = {\bar{{{\mu}}}}_{\rm r}(-{{r}})$${\bar{ \chi}}({{r}}) = -{\bar{ \chi}}(-{{r}})$
    Table 2.

    Symmetry relations of original field and adjoint field in the reciprocal waveguides.

    互易波导中原始场和伴随场之间的对称关系

    模式耦合理论传统模式耦合理论(CCMT)手征对称模式耦合理论(GCMT)广义模式耦合理论(GCMF)
    耦合模式展开式形式$\varPhi =\displaystyle \sum a_i\phi _i$$\varPhi = \displaystyle\sum a_i\phi _i$$\varPhi = \displaystyle\sum a_i\phi _i ^+ +b_i \psi _i ^-$
    守恒量光功率守恒 $\nabla \left({{{{E}}} _1 \times {{{H}}} _2 ^{\ast}} + {{{E}}} _2 ^{\ast} \times {{{H}}}_1\right) = 0$作用量守恒 $\nabla \left({{{{E}}} _1 \times {{{H}}} _2 } + {{{E}}} _2 \times {{{H}}}_1\right) = 0$作用量守恒 $\nabla \left({{{{E}}} _1 \times {{{H}}} _2 } + {{{E}}} _2 \times {{{H}}}_1\right) = 0$
    测试函数$\phi _j ^{\ast} $$\sigma \phi _j$$ \psi _j ^+$, $\psi _j ^-$
    本征方程${\bar{{L}}}{{\phi}}_i = \beta_i {\bar{{B}}}{{\phi}}_i $${\bar{{L}}}{{\phi}}_i = \beta_i {\bar{{B}}}{{\phi}}_i $${\bar{{L}}}{{\phi}}_i = \beta_i {\bar{{B}}}{{\phi}}_i$
    测试函数进行测试$\displaystyle\iiint \phi _j ^{\ast} [{\bar{{L} } }{{\phi} }_i-\beta_i {\bar{{B} } }{{\phi} }_i]{\rm{d} }v \!=\! 0$$\displaystyle\iiint \sigma \phi _j [{\bar{{L} } }{{\phi} }_i-\beta_i {\bar{{B} } }{{\phi} }_i]{\rm{d} }v \!=\! 0$$\displaystyle\iiint \psi _j \cdot [{\bar{{L} } }{{\phi} }_i \!-\! \beta_i {\bar{{B} } }{{\phi} }_i]{\rm{d} }v \!=\! 0$
    Table 3. Comparison between CCMT, GCMT and GCMF.