On a Sodium Nitrate Polarization Prism and a Polarization Plate of Scattering Type

抄録

Two types of polarizers are constructed, one being the “total reflection type” similar to the Feussner prism and the other is the “scattering type”, in which the principle of Christiansen filter holding for the polarization. The former is made of a thin single crystal of sodium nitrate grown between two prisms of SK5 glass or two glass plates which are cemented to two prisms of the same kind of glass by Canada balsam. No use of organic binders to attach the crystal to the glass remarkably simplifies the manufacturing process as well as protection of the polarizers from deteriorations due to the deliquenscence of the crystal.
The polarizer of the “scattering type” is constructed by binding directly two roughly ground surfaces of SK5 glass plates with a thin single crystal of sodium nitrate. As SK5 glass has the same refractive index with that of ordinary ray in sodium nitrate, and the orientation of the optical axis of the crystal is so chosen that it lies in the plane of the glass plate, the extraordinary ray is scattered at the boundaries between the crystal and glass, and only the ordinary ray proceeds in the direction of the incident light, when the natural light is incident upon it.