| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide optical glass which corrects the chromatic aberration of a glass lens with a high precision because it has high anomalous dispersion, has a high refractive index, a low dispersibility (high Abbe's number), and an abrasion equal to or lower than that of a conventional one, and thereby is easily subjected to polishing, and to provide an optical element and a preform. <P>SOLUTION: The optical glass includes, as a cationic component, at least one selected from the group comprising P<SP POS="POST">5+</SP>, Al<SP POS="POST">3+</SP>, Ca<SP POS="POST">2+</SP>, Ln<SP POS="POST">3+</SP>( Ln<SP POS="POST">3+</SP>is at least one selected from the group comprising Y<SP POS="POST">3+</SP>, La<SP POS="POST">3+</SP>, Gd<SP POS="POST">3+</SP>, Yb<SP POS="POST">2+</SP>and Lu<SP POS="POST">3+</SP>), and Mg<SP POS="POST">2+</SP>, Sr<SP POS="POST">2+</SP>, and Ba<SP POS="POST">2+</SP>, wherein the total content of Ln<SP POS="POST">3+</SP>is >1.1% and ≤10.0%, in terms of cation percentage, and, as an anionic component, F-, and has a refractive index (nd) of ≥1.55 and an Abbe's number (νd) of ≥55. <P>COPYRIGHT: (C)2012,JPO&INPIT |
