4.6 周期構造の多モード散乱行列

 周期的導体素子にフロケモードで展開した電界が入射したときの散乱行列を求めていく.境界面 $z=0$ においてフロケモードに対応する多端子対散乱行列(縦続接続に使用するため,モード数は少なくてよい)を定義するため,入射波側の接線電界 $\VEC{E}_{\tan}^{(1)}$ はフロケモード$m'$,$n'$によって次のように展開される. \begin{gather} \VEC{E}_{\tan}^{(1)} \Big| _{z=0} = \sum _{m',n'} \Big( a_{1[m'n']} \VEC{e}_{1[m'n']} + a_{1(m'n')} \VEC{e}_{1(m'n')} \Big) \nonumber \\ {} \hspace{20mm} + \sum _{m',n'} \Big( b_{1[m'n']} \VEC{e}_{1[m'n']} + b_{1(m'n')} \VEC{e}_{1(m'n')} \Big) \end{gather} ただし,$a_{1[m'n']}$,$a_{1(m'n')}$は各々TE波,TM波に対する入射波のフロケモード$m'$,$n'$のルート電力, $b_{1[m'n']}$,$b_{1(m'n')}$は各々TE波,TM波に対する反射波のフロケモード$m'$,$n'$のルート電力を示す. また,$\VEC{e}_{1[m'n']} $,$\VEC{e}_{1(m'n')}$は,TE波,TM波に対する電界のフロケモード関数を示し,次式で与えられる. \begin{eqnarray} \VEC{e}_{1[m'n']} &=& \sqrt{Z_{1[m'n']}} (\VEC{u}_{tm'n'} \times \VEC{u}_z) e^{j\VEC{k}_{tm'n'} \cdot \VECi{\rho}} \\ \VEC{e}_{1(m'n')} &=& \sqrt{Z_{1(m'n')}} \VEC{u}_{tm'n'} e^{j\VEC{k}_{tm'n'} \cdot \VECi{\rho}} \end{eqnarray} 行列形式では, \begin{eqnarray} \VEC{E}_{\tan}^{(1)} \Big| _{z=0} &=& \begin{pmatrix} [\VEC{e}'_{1_{\TE}}]^t & [\VEC{e}'_{1_{\TM}}]^t \end{pmatrix} \left\{ \begin{pmatrix} \VECi{a}_{1_{\TE}} \\ \VECi{a}_{1_{\TM}} \end{pmatrix} + \begin{pmatrix} \VECi{b}_{1_{\TE}} \\ \VECi{b}_{1_{\TM}} \end{pmatrix} \right\} \nonumber \\ &=& [\VEC{e}'_1]^t \Big\{ \VECi{a}_1 + \VECi{b}_1 \Big\} \end{eqnarray} ここで, \begin{gather} [\VEC{e}'_1]^t \equiv \begin{pmatrix} [\VEC{e}'_{1_{\TE}}]^t & [\VEC{e}'_{1_{\TM}}]^t \end{pmatrix} \end{gather} また, \begin{eqnarray} \VECi{a}_1 &\equiv& \begin{pmatrix} \VECi{a}_{1_{\TE}} \\ \VECi{a}_{1_{\TM}} \end{pmatrix} \\ \VECi{b}_1 &\equiv& \begin{pmatrix} \VECi{b}_{1_{\TE}} \\ \VECi{b}_{1_{\TM}} \end{pmatrix} \end{eqnarray} ただし, $[\VEC{e}'_{1_{\TE}}]^t$,$[\VEC{e}'_{1_{\TM}}]^t$は各々 $\VEC{e}_{1[m'n']}^t$,$\VEC{e}_{1(m'n')}^t$を要素とする行ベクトルを示す. また,$\VECi{a}_{1_{\TE}}$,$\VECi{a}_{1_{\TM}}$は各々 $a_{1[m'n']}$,$a_{1(m'n')}$を要素とする列ベクトル, $\VECi{b}_{1_{\TE}}$,$\VECi{b}_{1_{\TM}}$は各々 $b_{1[m'n']}$,$b_{1(m'n')}$を要素とする列ベクトルを示す. モーメント法より求められる結果を基に, フロケモードで接線電界を展開すると, \begin{eqnarray} \VEC{E}_{\tan}^{(1)} \Big| _{z=0} &=& \sum _{m',n'} \Big( a_{1[m'n']} \VEC{e}_{1[m'n']} + a_{1(m'n')} \VEC{e}_{1(m'n')} \Big) + \VEC{E}_{s,\tan}^{(1)} \Big| _{z=0} \nonumber \\ &&+ \sum _{m',n'} \Big( R_{[m'n']}^+ a_{1[m'n']} \VEC{e}_{1[m'n']} + R_{(m'n')}^+ a_{1(m'n')} \VEC{e}_{1(m'n')} \Big) \nonumber \\ &\equiv& \begin{pmatrix} [\VEC{e}'_{1_{\TE}}] & [\VEC{e}'_{1_{\TM}}] \end{pmatrix} \left\{ \begin{pmatrix} \VECi{a}_{1_{\TE}} \\ \VECi{a}_{1_{\TM}} \end{pmatrix} + \begin{pmatrix} [R^+_{_{\TE}}]_d & 0 \\ 0 & [R^+_{_{\TM}}]_d \end{pmatrix} \begin{pmatrix} \VECi{a}_{1_{\TE}} \\ \VECi{a}_{1_{\TM}} \end{pmatrix} \right\} \nonumber \\ &&+ \sum _{m',n'} \Big( \VEC{E}_{s[m'n']} + \VEC{E}_{s(m'n')} \Big) \end{eqnarray} ただし, $[R^+_{_{\TE}}]_d$,$[R^+_{_{\TM}}]_d$は,各々$R^+_{[m'n']} $(TE波),$R^+_{(m'n')} $(TM波)を対角要素とする対角行列を示し, \begin{eqnarray} R^{+}_{[m'n']} &=& \frac{Y_{1[m'n']} - Y_{2[m'n']}}{Y_{1[m'n']} + Y_{2[m'n']}} \nonumber \\ &=& \frac{k_{1zm'n'} - k_{2zm'n'}}{k_{1zm'n'} + k_{2zm'n'}} \\ R^{+}_{(m'n')} &=& \frac{Z_{2(m'n')} - Z_{1(m'n')}}{Z_{2(m'n')} + Z_{1(m'n')}} \nonumber \\ &=& \frac{k_{2zm'n'} - n^2 k_{1zm'n'}}{k_{2zm'n'} + n^2 k_{1zm'n'}} \end{eqnarray} ここで, \begin{gather} n^2 \equiv \frac{k^2_2}{k^2_1} \end{gather} いま, $\mu _1 = \mu _2$, $\epsilon _1 = \epsilon _0 \epsilon _{r1}$, $\epsilon _2 = \epsilon _0 \epsilon _{r2}$ のとき, \begin{eqnarray} n^2 &=& \frac{\epsilon _{r2}}{\epsilon _{r1}} \nonumber \\ &=& \frac{|\epsilon _{r2}| \big( 1-j\tan \delta _2 \big) }{|\epsilon _{r1}| \big( 1-j\tan \delta _1 \big)} \end{eqnarray} フロケモードの散乱波については, \begin{eqnarray} &&\VEC{E}_{s[m'n']} + \VEC{E}_{s(m'n')} \nonumber \\ &=& \frac{1}{d_xd_y} \widetilde{\DYA{G}}_T^{_{(d_i)EJ}} (\VEC{k}_{tm'n'}) \cdot \SDV{J}_s (\VEC{k}_{tm'n'}) e^{j\VEC{k}_{tm'n'} \cdot \VECi{\rho}} \nonumber \\ &=& \frac{1}{d_xd_y} \begin{pmatrix} \VEC{u}_x & \VEC{u}_y \end{pmatrix} \begin{pmatrix} \SDS{G}_{xx}^{m'n'} & \SDS{G}_{xy}^{m'n'} \\ \SDS{G}_{yx}^{m'n'} & \SDS{G}_{yy}^{m'n'} \end{pmatrix} \begin{pmatrix} \SDS{J}_x^{m'n'} \\ \SDS{J}_y^{m'n'} \end{pmatrix} e^{j\VEC{k}_{tm'n'} \cdot \VECi{\rho}} \nonumber \\ &=& \frac{1}{d_xd_y} \begin{pmatrix} \VEC{u}_{tm'n'} \times \VEC{u}_z & \VEC{u}_{tm'n'} \end{pmatrix} \begin{pmatrix} (\VEC{u}_{tm'n'} \times \VEC{u}_z) \cdot \VEC{u}_x & (\VEC{u}_{tm'n'} \times \VEC{u}_z) \cdot \VEC{u}_y \\ \VEC{u}_{tm'n'} \cdot \VEC{u}_x & \VEC{u}_{tm'n'} \cdot \VEC{u}_y \end{pmatrix} \nonumber \\ &&\cdot \begin{pmatrix} \SDS{G}_{xx}^{m'n'} & \SDS{G}_{xy}^{m'n'} \\ \SDS{G}_{yx}^{m'n'} & \SDS{G}_{yx}^{m'n'} \end{pmatrix} \begin{pmatrix} \SDS{J}_x^{m'n'} \\ \SDS{J}_y^{m'n'} \end{pmatrix} e^{j\VEC{k}_{tm'n'} \cdot \VECi{\rho}} \nonumber \\ &=& \frac{1}{d_xd_y} \begin{pmatrix} \VEC{e}_{1[m'n']} & \VEC{e}_{1(m'n')} \end{pmatrix} \begin{pmatrix} \sqrt{Y_{1[m'n']}} & 0 \\ 0 & \sqrt{Y_{1(m'n')}} \end{pmatrix} \nonumber \\ &&\cdot \begin{pmatrix} \SDS{G}_{ux}^{m'n'} & \SDS{G}_{uy}^{m'n'} \\ \SDS{G}_{tx}^{m'n'} & \SDS{G}_{ty}^{m'n'} \end{pmatrix} \begin{pmatrix} \SDS{J}_x^{m'n'} \\ \SDS{J}_y^{m'n'} \end{pmatrix} \end{eqnarray} ここで, \begin{eqnarray} \widetilde{\DYA{G}}_T^{_{(d_i)EJ}} &=& \SDS{G}_{xx}^{m'n'} \VEC{u}_x \VEC{u}_x + \SDS{G}_{xy}^{m'n'} \VEC{u}_x \VEC{u}_y + \SDS{G}_{yx}^{m'n'} \VEC{u}_y \VEC{u}_x + \SDS{G}_{yy}^{m'n'} \VEC{u}_y \VEC{u}_y \nonumber \\ &\equiv& \SDS{G}_{ux}^{m'n'} \VEC{u}_{um'n'} \VEC{u}_x + \SDS{G}_{uy}^{m'n'} \VEC{u}_{um'n'} \VEC{u}_y \nonumber \\ &&+ \SDS{G}_{tx}^{m'n'} \VEC{u}_{tm'n'} \VEC{u}_x + \SDS{G}_{ty}^{m'n'} \VEC{u}_{tm'n'} \VEC{u}_y \\ \VEC{u}_{um'n'} &\equiv& \VEC{u}_{tm'n'} \times \VEC{u}_z \end{eqnarray} これより,散乱波は, \begin{eqnarray} \VEC{E}_{s,\tan}^{(1)} \Big| _{z=0} &=& \sum _{m',n'} \Big( \VEC{E}_{s[m'n']} + \VEC{E}_{s(m'n')} \Big) \nonumber \\ &=& \frac{1}{d_xd_y} \sum _{m',n'} \begin{pmatrix} \VEC{e}_{1[m'n']} & \VEC{e}_{1(m'n')} \end{pmatrix} \begin{pmatrix} \sqrt{Y_{1[m'n']}} & 0 \\ 0 & \sqrt{Y_{1(m'n')}} \end{pmatrix} \nonumber \\ &&\cdot \begin{pmatrix} \SDS{G}_{ux}^{m'n'} & \SDS{G}_{uy}^{m'n'} \\ \SDS{G}_{tx}^{m'n'} & \SDS{G}_{ty}^{m'n'} \end{pmatrix} \begin{pmatrix} \SDS{J}_x^{m'n'} \\ \SDS{J}_y^{m'n'} \end{pmatrix} \end{eqnarray} さらに,$m'$,$n'$に対して行列として扱うと, \begin{eqnarray} \VEC{E}_{s,\tan}^{(1)} \Big| _{z=0} &=& \frac{1}{d_xd_y} \begin{pmatrix} [ \VEC{e}_{1_{\TE}}' ]^t & [ \VEC{e}_{1_{\TM}}' ]^t \end{pmatrix} \begin{pmatrix} \big[ \sqrt{Y_{1_{\TE}}} \big] _d & 0 \\ 0 & \big[ \sqrt{Y_{1_{\TM}}} \big] _d \end{pmatrix} \nonumber \\ &&\cdot \begin{pmatrix} \big[ \SDS{G}_{ux} \big] & \big[ \SDS{G}_{uy} \big] \\ \big[ \SDS{G}_{tx} \big] & \big[ \SDS{G}_{ty} \big] \end{pmatrix} \begin{pmatrix} \SDS{\VECi{J}}_x \\ \SDS{\VECi{J}}_y \end{pmatrix} \nonumber \\ &\equiv& \frac{1}{d_xd_y} [ \VEC{e}'_1 ]^t \big[ \sqrt{Y_1} \big] _d \big[ \SDS{G}_{ut,xy} \big] \begin{pmatrix} \SDS{\VECi{J}}_x \\ \SDS{\VECi{J}}_y \end{pmatrix} \end{eqnarray} ここで, \begin{align} &\big[ \sqrt{Y_1} \big] _d \equiv \begin{pmatrix} \big[ \sqrt{Y_{1_{\TE}}} \big] _d & 0 \\ 0 & \big[ \sqrt{Y_{1_{\TM}}} \big] _d \end{pmatrix} \\ &\big[ \SDS{G}_{ut,xy} \big] \equiv \begin{pmatrix} \big[ \SDS{G}_{ux} \big] & \big[ \SDS{G}_{uy} \big] \\ \big[ \SDS{G}_{tx} \big] & \big[ \SDS{G}_{ty} \big] \end{pmatrix} \end{align} ただし, $\big[ \sqrt{Y_{1_{\TE}}} \big] _d$,$\big[ \sqrt{Y_{1_{\TM}}} \big] _d$は各々 $\sqrt{Y_{1[m'n']}}$,$\sqrt{Y_{1(m'n')}}$を対角要素とする対角行列, $\big[ \SDS{G}_{ux} \big]$,$\big[ \SDS{G}_{uy} \big]$, $\big[ \SDS{G}_{tx} \big]$,$\big[ \SDS{G}_{ty} \big]$ は各々 $\SDS{G}_{ux}^{m'n'}$,$\SDS{G}_{uy}^{m'n'}$, $\SDS{G}_{tx}^{m'n'}$,$\SDS{G}_{ty}^{m'n'}$ を要素とする行列を示す.また, $\SDS{\VECi{J}}_x$,$\SDS{\VECi{J}}_y$は各々 $\SDS{J}_x^{m'n'}$,$\SDS{J}_y^{m'n'}$ を要素とする列ベクトルを示し,次のように基底関数で展開される. \begin{gather} \begin{pmatrix} \SDS{\VECi{J}}_x \\ \SDS{\VECi{J}}_y \end{pmatrix} = \big[ \SDS{B} \Big] \begin{pmatrix} \VECi{I}_x \\ \VECi{I}_y \end{pmatrix} \end{gather} ここで, \begin{gather} \big[ \SDS{B} \Big] = \begin{pmatrix} \big[ \SDS{B}_x \Big] & 0 \\ 0 & \big[ \SDS{B}_y \Big] \end{pmatrix} \end{gather} ただし, $\big[ \SDS{B}_x \Big]$,$\big[ \SDS{B}_y \Big]$は各々 基底関数$\SDS{B}_{xpq}^{m'n'}$,$\SDS{B}_{ypq}^{m'n'}$を要素とする行列を示す. また,$\VECi{I}_x$,$\VECi{I}_y$は $I_{xpq}$,$I_{ypq}$を要素とする列ベクトルを示し, \begin{gather} \begin{pmatrix} \VECi{I}_x \\ \VECi{I}_y \end{pmatrix} = \Big[ Z \Big] ^{-1} \begin{pmatrix} \VECi{V}_x \\ \VECi{V}_y \end{pmatrix} \end{gather} ここで, \begin{gather} \Big[ Z \Big] = \begin{pmatrix} \Big[ Z_{xx} \Big] & \Big[ Z_{xy} \Big] \\ \Big[ Z_{yx} \Big] & \Big[ Z_{yy} \Big] \end{pmatrix} \end{gather} そして,$\VECi{V}_x$,$\VECi{V}_y$は次式で求められる. \begin{eqnarray} \begin{pmatrix} \VECi{V}_x \\ \VECi{V}_y \end{pmatrix} &=& - \begin{pmatrix} \Big[ \SDS{T}_{xu}^* \big]^t & \Big[ \SDS{T}_{xt}^* \big]^t \\ \Big[ \SDS{T}_{yu}^* \big]^t & \Big[ \SDS{T}_{yt}^* \big]^t \end{pmatrix} \Big\{ [U] + [R^{+}]_d \Big\} \begin{pmatrix} V_{1_{\TE}}^+ \\ V_{1_{\TM}}^+ \end{pmatrix} \nonumber \\ &=& - \Big[ \SDS{T}_{xy,ut}^* ]^t \Big\{ [U] + [R^{+}]_d \Big\} [ \sqrt{Z_1} ]_d \VECi{a}_1 \end{eqnarray} ここで, \begin{align} &\Big[ \SDS{T}_{xy,ut}^* ]^t \equiv \begin{pmatrix} \Big[ \SDS{T}_{xu}^* \big]^t & \Big[ \SDS{T}_{xt}^* \big]^t \\ \Big[ \SDS{T}_{yu}^* \big]^t & \Big[ \SDS{T}_{yt}^* \big]^t \end{pmatrix} \\ &[ \sqrt{Z_1} ]_d \equiv \begin{pmatrix} [ \sqrt{Z_{1_{\TE}}} ]_d & 0 \\ 0 & [ \sqrt{Z_{1_{\TM}}} ]_d \end{pmatrix} \end{align} ただし,$[U]$は単位行列を示す.また, $[ \sqrt{Z_{1_{\TE}}} ]_d$,$[ \sqrt{Z_{1_{\TM}}} ]_d$ は各々 $\sqrt{Z_{1[m'n']}}$,$\sqrt{Z_{1(m'n')}}$ を対角要素とする対角行列を示す.いま, \begin{eqnarray} \Big[ Z' \Big] &=& \begin{pmatrix} \Big[ Z'_{xx} \Big] & \Big[ Z'_{xy} \Big] \\ \Big[ Z'_{yx} \Big] & \Big[ Z'_{yy} \Big] \end{pmatrix} \nonumber \\ &\equiv& d_x d_y \Big[ Z \Big] \end{eqnarray} とおくと,行列 $\Big[ Z'_{xx} \Big]$,$\Big[ Z'_{xy} \Big]$, $\Big[ Z'_{yx} \Big]$,$\Big[ Z'_{yy} \Big]$ の各々の要素 $z_{kl,pq}^{xx\prime}$,$z_{kl,pq}^{xy\prime}$, $z_{kl,pq}^{yx\prime}$,$z_{kl,pq}^{yy\prime}$ は次のようになる. \begin{eqnarray} z_{kl,pq}^{xx\prime} &=& \sum _{m,n} \SDS{T}_{xkl}^{mn*} \SDS{G}_{xx}^{mn} \SDS{B}_{xpq}^{mn} - d_x d_y Z_s \int _S T_{xkl}^* B_{xpq} dS \\ z_{kl,pq}^{xy\prime} &=& \sum _{m,n} \SDS{T}_{xkl}^{mn*} \SDS{G}_{xy}^{mn} \SDS{B}_{ypq}^{mn} \\ z_{kl,pq}^{yx\prime} &=& \sum _{m,n} \SDS{T}_{ykl}^{mn*} \SDS{G}_{yx}^{mn} \SDS{B}_{xpq}^{mn} \\ z_{kl,pq}^{yy\prime} &=& \sum _{m,n} \SDS{T}_{ykl}^{mn*} \SDS{G}_{yy}^{mn} \SDS{B}_{ypq}^{mn} - d_x d_y Z_s \int _S T_{ykl}^* B_{ypq} dS \end{eqnarray} また, \begin{eqnarray} \Big[ \SDS{T}^{Z*} ]^t &\equiv& \Big[ \SDS{T}_{xy,ut}^* ]^t [ \sqrt{Z_1} ]_d \nonumber \\ &\equiv& \begin{pmatrix} \Big[ \SDS{T}_{xu}^{Z*} \big]^t & \Big[ \SDS{T}_{xt}^{Z*} \big]^t \\ \Big[ \SDS{T}_{yu}^{Z*} \big]^t & \Big[ \SDS{T}_{yt}^{Z*} \big]^t \end{pmatrix} \end{eqnarray} とおいたときの行列 $\Big[ \SDS{T}_{xu}^{Z*} \big]^t$,$\Big[ \SDS{T}_{xt}^{Z*} \big]^t$, $\Big[ \SDS{T}_{yu}^{Z*} \big]^t$,$\Big[ \SDS{T}_{yt}^{Z*} \big]^t$ の要素 $\SDS{t}_{kl,m'n'}^{xu*}$,$\SDS{t}_{kl,m'n'}^{xt*}$, $\SDS{t}_{kl,m'n'}^{yu*}$,$\SDS{t}_{kl,m'n'}^{yt*}$ は各々次のようになる. \begin{eqnarray} \SDS{t}_{kl,m'n'}^{xu*} &=& \SDS{T}_{xkl}^{m'n'*} \sqrt{Z_{1[m'n']}} \sin \phi _{m'n'} \\ \SDS{t}_{kl,m'n'}^{xt*} &=& \SDS{T}_{xkl}^{m'n'*} \sqrt{Z_{1(m'n')}} \sin \phi _{m'n'} \\ \SDS{t}_{kl,m'n'}^{yu*} &=& -\SDS{T}_{ykl}^{m'n'*} \sqrt{Z_{1[m'n']}} \cos \phi _{m'n'} \\ \SDS{t}_{kl,m'n'}^{yt*} &=& \SDS{T}_{ykl}^{m'n'*} \sqrt{Z_{1(m'n')}} \cos \phi _{m'n'} \end{eqnarray} また, \begin{eqnarray} \big[ \SDS{G}^{YB} \Big] &\equiv& \big[ \sqrt{Y_1} \big]_d \big[ \SDS{G}_{ut,xy} \big]_d \big[ \SDS{B} \Big] \nonumber \\ &\equiv& \begin{pmatrix} \big[ \SDS{G}_{ux}^{YB} \Big] & \big[ \SDS{G}_{uy}^{YB} \Big] \\ \big[ \SDS{G}_{tx}^{YB} \Big] & \big[ \SDS{G}_{ty}^{YB} \Big] \end{pmatrix} \end{eqnarray} とおいたときの行列$\big[ \SDS{G}_{ux}^{YB} \Big]$,$\big[ \SDS{G}_{uy}^{YB} \Big]$, $\big[ \SDS{G}_{tx}^{YB} \Big]$,$\big[ \SDS{G}_{ty}^{YB} \Big]$の要素 $\SDS{g}_{m'n',kl}^{ux}$,$\SDS{g}_{m'n',kl}^{uy}$, $\SDS{g}_{m'n',kl}^{tx}$,$\SDS{g}_{m'n',kl}^{ty}$は各々次のようになる. \begin{eqnarray} \SDS{g}_{m'n',kl}^{ux} &=& \sqrt{Y_{1[m'n']}} \left( \SDS{G}_{xx}^{m'n'} \sin \phi _{m'n'} + \SDS{G}_{yx}^{m'n'} \cos \phi _{m'n'} \right) \SDS{B}_{xkl}^{m'n'} \\ \SDS{g}_{m'n',kl}^{uy} &=& \sqrt{Y_{1[m'n']}} \left( \SDS{G}_{xy}^{m'n'} \sin \phi _{m'n'} + \SDS{G}_{yy}^{m'n'} \cos \phi _{m'n'} \right) \SDS{B}_{ykl}^{m'n'} \\ \SDS{g}_{m'n',kl}^{tx} &=& \sqrt{Y_{1(m'n')}} \left( -\SDS{G}_{xx}^{m'n'} \cos \phi _{m'n'} + \SDS{G}_{yx}^{m'n'} \sin \phi _{m'n'} \right) \SDS{B}_{xkl}^{m'n'} \\ \SDS{g}_{m'n',kl}^{ty} &=& \sqrt{Y_{1(m'n')}} \left( -\SDS{G}_{xy}^{m'n'} \cos \phi _{m'n'} + \SDS{G}_{yy}^{m'n'} \sin \phi _{m'n'} \right) \SDS{B}_{ykl}^{m'n'} \end{eqnarray} さらに, \begin{eqnarray} \big[ S_0 \big] &\equiv& -\big[ \sqrt{Y_1} \big]_d \big[ \SDS{G}_{ut,xy} \big]_d \big[ \SDS{B} \Big] \Big[ Z' \Big] ^{-1} \Big[ \SDS{T}_{xy,ut}^* ]^t [ \sqrt{Z_1} ]_d \nonumber \\ &=& \big[ \SDS{G}^{YB} \Big] \Big[ Z' \Big] ^{-1} \Big[ \SDS{T}^{Z*} ]^t \end{eqnarray} とおくと, \begin{eqnarray} \VEC{E}_{s,\tan}^{(1)} \Big| _{z=0} &=& -[ \VEC{e}'_1 ]^t \big[ \sqrt{Y_1} \big]_d \big[ \SDS{G}_{ut,xy} \big]_d \big[ \SDS{B} \Big] \Big[ Z' \Big] ^{-1} \Big[ \SDS{T}_{xy,ut}^* ]^t \nonumber \\ &&\cdot \Big\{ [U] + [R^{+}]_d \Big\} [ \sqrt{Z_1} ]_d \VECi{a}_1 \nonumber \\ &=& [ \VEC{e}'_1 ] \big[ S_0 \big] \Big\{ [U] + [R^{+}]_d \Big\} \VECi{a}_1 \end{eqnarray} よって, \begin{gather} [\VEC{e}'_1] \Big\{ \VECi{a}_1 + \VECi{b}_1 \Big\} = [\VEC{e}'_1] \Big\{ \VECi{a}_1 + [R^{+}]_d \VECi{a}_1 \Big\} + [ \VEC{e}'_1 ] \big[ S_0 \big] \Big\{ [U] + [R^{+}]_d \Big\} \VECi{a}_1 \nonumber \\ \VECi{a}_1+ \VECi{b}_1 = \Big\{ \VECi{a}_1 + [R^{+}]_d \VECi{a}_1 \Big\} + \big[ S_0 \big] \Big\{ [U] + [R^{+}]_d \Big\} \VECi{a}_1 \nonumber \\ \VECi{b}_1 = \Big( [R^{+}]_d + \big[ S_0 \big] \Big\{ [U] + [R^{+}]_d \Big\} \Big) \VECi{a}_1 \equiv [S_{11}] \VECi{a}_1 \end{gather} したがって, $[S_{11}]$ は次のようになる. \begin{gather} [S_{11}] = [R^{+}]_d + \big[ S_0 \big] \Big( [U] + [R^{+}]_d \Big) \end{gather} 同様にして, $[S_{22}]$ は(導出省略), \begin{gather} [S_{22}] = [R^{-}]_d + \big[ S_0 \big] \Big( [U] + [R^{-}]_d \Big) \end{gather} ここで, \begin{gather} [ R^- ]_d = \begin{pmatrix} [ R^-_{_{\TE}} ]_d & 0 \\ 0 & [ R^-_{_{\TM}} ]_d \end{pmatrix} \end{gather} ただし, $[R^-_{_{\TE}}]_d$,$[R^-_{_{\TM}}]_d$は,各々 $R^-_{[m'n']} $(TE波),$R^-_{(m'n')} $(TM波)を対角要素とする対角行列を示し, \begin{eqnarray} R^{-}_{[m'n']} &=& \frac{Y_{2[m'n']} - Y_{1[m'n']}}{Y_{2[m'n']} + Y_{1[m'n']}} \nonumber \\ &=& -R^{+}_{[m'n']} \\ R^{-}_{(m'n')} &=& \frac{Z_{2(m'n')} - Z_{1(m'n')}}{Z_{2(m'n')} + Z_{1(m'n')}} \nonumber \\ &=& -R^{+}_{(m'n')} \end{eqnarray} よって, \begin{gather} [R^{-}]_d = - [R^{+}]_d \end{gather} したがって, $[S_{22}]$ は, \begin{gather} [S_{22}] = -[R^{+}]_d + \big[ S_0 \big] \Big( [U] - [R^{+}]_d \Big) \end{gather} また, $[S_{21}]$ は(導出省略), \begin{gather} [S_{21}] = [T^{+}]_d + \big[ S_0 \big] [T^{+}]_d \end{gather} ここで, \begin{gather} [ T^+ ]_d = \begin{pmatrix} [ T^+_{_{\TE}} ]_d & 0 \\ 0 & [ T^+_{_{\TM}} ]_d \end{pmatrix} \end{gather} ただし, $[T^+_{_{\TE}}]_d$,$[T^+_{_{\TM}}]_d$は,各々 $T^+_{[m'n']} $(TE波),$T^+_{(m'n')} $(TM波)を対角要素とする対角行列を示し, \begin{eqnarray} T^{+}_{[m'n']} &=& \frac{Y_{1[m'n']}}{Y_{2[m'n']} + Y_{1[m'n']}} \nonumber \\ &=& 1+R^{+}_{[m'n']} \\ T^{+}_{(m'n')} &=& \frac{Y_{1(m'n')}}{Y_{2(m'n')} + Y_{1(m'n')}} \nonumber \\ &=& 1+R^{+}_{(m'n')} \end{eqnarray} よって, \begin{gather} [T^{+}]_d = [U] + [R^{+}]_d \end{gather} したがって, $[S_{21}]$ は, \begin{eqnarray} [S_{21}] &=& \Big( [U] + [R^{+}]_d \Big) + \big[ S_0 \big] \Big( [U] + [R^{+}]_d \Big) \nonumber \\ &=& \Big( [U] + [S_0] \Big) \Big( [U] + [R^{+}]_d \Big) \end{eqnarray} 同様にして, $[S_{12}]$ は, \begin{gather} [S_{12}] = \Big( [U] + [S_0] \Big) \Big( [U] - [R^{+}]_d \Big) \end{gather} これより,散乱行列$[S]$は, \begin{eqnarray} &&[S] = \begin{pmatrix} [ S_{11} ] & [ S_{12} ] \\ [ S_{21} ] & [ S_{22} ] \end{pmatrix} \nonumber \\ &=& \begin{pmatrix} \left[ [R^{+}]_d + \big[ S_0 \big] \Big( [U] + [R^{+}]_d \Big) \right] & \left[ \Big( [U] + [S_0] \Big) \Big( [U] - [R^{+}]_d \Big) \right] \\ \left[ \Big( [U] + [S_0] \Big) \Big( [U] + [R^{+}]_d \Big) \right] & \left[ -[R^{+}]_d + \big[ S_0 \big] \Big( [U] - [R^{+}]_d \Big) \right] \end{pmatrix} \end{eqnarray}