%?This?function?linearPolarizerMueller?is?to?calculate?the?Mueler?matrix
%?of?the?linear?polarizer?in?the?polarization?optics.
%?theta?-?fast?axis?at?the?angle?theta
%?the?ourput?matrix?linearPolarizer?is?a?4x4?one

function?linearPolarizer?=?linearPolarizerMueller（theta）

%notations?on?some?abbreviations?of?complex?elements
cosTwoTheta?=?cos（2?*?theta）;
sinTwoTheta?=?sin（2?*?theta）;
cosTwoThetaSq?=?cos（2?*?theta）?*?cos（2?*?theta）;
sinTwoThetaSq?=?sin（2?*?theta）?*?sin（2?*?theta）;

%notations?of?elemen