Optical glass for prism, process for the production thereof, and optical part for prism

摘要

An optical glass for a prism, which has high transmittance, high homogeneity and excellent thermal stability, and an optical part for a prism, which is formed of the optical glass, the optical glass being an optical glass (1) wherein the absolute value of KDELTAt represented by the relational expression (I), 1 $\begin{array}{cc}Kitit\mathrm{Delta}ititt=\left[\left(\mathrm{specific}itit\mathrm{heat}x\mathrm{specific}itit\mathrm{gravity}\right)/\mathrm{thermal}itit\mathrm{conductivity}\right]x\mathrm{Young}\text{'}itsitit\mathrm{modulus}x\mathrm{thermal}itit\mathrm{expansion}itit\mathrm{coefficient}x\left(1-\mathrm{Poisson}\text{'}itsitit\mathrm{ratio}\right)x\mathrm{photoelastic}itit\mathrm{constant}& \left(I\right)\end{array}$ is less than 3,000x10-2 m.s/(g.K), and (1) which contains SiO2 and B2O3 as essential components and substantially contains none of P