In order to avoid the huge power penalty caused by nonlinear effects and polarization mode dispersion

this paper studies the technologies for polarization-based encoding.It proposes a triple-photoelastic-modulator（triple-PEM）-based polarization information acquisition method

which overcomes the shortcomings of the existing methods

such as inability to use array detector to effectively collect and modulate higher frequencies

and presents the MATLAB simulation and experimental results.These results verify its theoretical and practical feasibility.