| 摘要 |
<p>An translucent ceramic comprising as a main component a composition of the general formula: Ba{Tix1Mx2(Mg1-tZnt)y(Ta1-uNbu)z}vOw (wherein M is at least one selected from among Sn, Zr and Hf; x1+x2+y+z=1; the relationships 0.015<=x1+x2<=0.90, 0<x1<=0.90, 0<=x2<=0.60, 1.60<=z/y<=2.40, 1.00<=v<=1.05, 0<t<1 and 0<=u<=1 are satisfied; and w is a positive number for maintaining electrical neutrality). This translucent ceramic exhibits a high linear transmittance over a wide wavelength band, a high refractive index and a wide regulation range for refractive index and Abbe number and is free of birefringence, so that lens (2) constructed with the use of the same can be advantageously used in, for example, optical pickup (9) whose downsizing and thickness reduction are demanded.</p> |
