A special kind of metal nanograting which has excellent performance on polarization state controlling, is fabricated by
means of interference lithography, reactive ion etching (RIE) and two-time-evaporation coating with metal. The MNG
can produce angle-free elliptically polarized light via rolling the direction of grating, so it will have wide and convenient
applications in the systems which need flexible polarization orientation. We fabricate the MNG and test its performances
on polarization state controlling, then we simulate the process with software.