抄録
The polarization characteristics of the sodium nitrate polarization prism are measured. Polarization effect is complete from 350 to 1,000 mμ; and transmission of light uncorrected for reflection at the surfaces is about 90% at above 400 mμ and 37% at 350 mμ. Possibility of making a polarization prism for a wide wavelength range from 250 to 1,000 mμ is discussed.