| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical glass having a high temperature coefficient (dn/dT) of a relative refracting ratio, a character capable of correcting the influence of an image forming property or others, a low Abbe's number (ν<SB POS="POST">d</SB>), a high permeability to visible light, no adverse affect to a glass environment, and a preform and an optical element using the same. <P>SOLUTION: The optical glass contains, by mass, 55.0 to 95.0% of a Bi<SB POS="POST">2</SB>O<SB POS="POST">3</SB>component and 4.0 to 35.0% of a B<SB POS="POST">2</SB>O<SB POS="POST">3</SB>component to the total mass in terms of an oxide composition and the temperature coefficient (20 to 40°C) of the relative refracting ratio (546.07 nm) is 3.0×10<SP POS="POST">-6</SP>(°C<SP POS="POST">-1</SP>) or more. The preform and the optical element comprises the optical glass. <P>COPYRIGHT: (C)2013,JPO&INPIT |
