| 摘要 |
PURPOSE:To obtain the small-sized, thin, and low-price polarizing element which has superior mass-productivity by arranging 1st areas which have specific one- dimensional periodic structure and 2nd areas which have surface oxidized layers alternately in a lattice shape. CONSTITUTION:The 1st areas 1 which have surface irregular type one- dimensional periodic structure which has a pitch less than a half of the wavelength of a light wave and the 2nd areas 2 which have the surface oxidized layers are arranged on a substrate 3 alternately in a lattice shape. Namely, diffraction gratings are used to obtain 0-th order diffraction efficiency, i.e. transmissivity which is 100% to specific polarized light and 0% to polarized light perpendicular to said specific polarized light, thereby constituting the polarizing element which has a polarization beam splitter function. Consequently, birefringent crystal is not required, the element is composed of a material which is easily obtained at low cost like silicon, and many elements can easily be manufactured at the same time by photolithography while assembly is not required, so that cost is reducible. Further, the substrate is only thick enough to give strength to the element, so the thin, lightweight element can be constituted. |
