| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a translucent ceramic free from the occurrence of birefringence and having excellent optical characteristics, and an optical device using the same. <P>SOLUTION: The translucent ceramic has a composition which is expressed by a general formula, Ba(Zr<SB>x</SB>Zn<SB>y</SB>Ta<SB>z</SB>)<SB>v</SB>O<SB>w</SB>(where, x+y+z=1; 0.01≤x≤0.06; 0.29≤y≤0.36; 0.58≤z≤0.7; 1<v≤1.05; (w) is an optional number) and in which (x), (y) and (z) in the general formula are in a region surrounded by a quadrangle ABCD in a ternary diagram expressed by Figure 1. The translucent ceramic has the refractive index of ≥2.0 and ≥20% linear transmissivity and does not cause the birefringence. The translucent ceramic is used as a collimating lens, a half mirror, an objective lens, a condenser lens or the like in an optical pickup. <P>COPYRIGHT: (C)2004,JPO |
