| 摘要 |
Provided are: lanthanum fluoride single crystals made from lanthanum fluoride single crystals characterized in that an alkaline earth metal is added, and the internal transmittance of light of a wavelength of 9.3 μm is 85%/mm or greater, the lanthanum fluoride single crystals having high permeability in the infrared region, and it being possible to suitably use the lanthanum fluoride single crystals in laser phase plates, in lenses of laser processing machines, gas detectors, flame detectors, infrared cameras, and the like, and in optical window materials, etc.; and optical components. |
