| 摘要 |
<p>A translucent ceramic composed mainly of a composition of the general formula: Ba{Mx(Mg1-tZnt)y(Ta1-uNbu)z}vOw (wherein M is at least one selected from among Sn, Zr and Hf; x+y+z=1; the relationships 0.015<=x<=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 sustaining electrical neutrality). This translucent ceramic exhibits high linear transmittance over a wide wavelength region, high refractive index and wide regulation range for refractive index and Abbe number and is free from any birefringence. Consequently, lens (2) constituted using this translucent ceramic can be advantageously applied to, for example, light pickup (9) whose miniaturization and thickness reduction are demanded.</p> |
