Optical glass, optical element, optical instrument, and method for manufacturing optical glass
An optical glass includes La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ as a cation configuring glass. La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ which satisfy 10 cat %≤La 3+ ≤20 cat %, 10 cat %≤Zn 2+ ≤60 cat %, 20 cat %≤Nb 5+ ≤60 cat %, and 0 cat %≤Ti 4+ ≤40 cat % expressed by cation %.
1. An optical glass comprising:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,
wherein B 2 O 3 is not contained in the optical glass.
2. The optical glass according to claim 1 , satisfying:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤6.0 cat %;
30 cat %≤Nb 5+ ≤60 cat %; and
Ti 4+ =0 cat %.
3. The optical glass according to claim 1 , satisfying
60 cat % (Total amount of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Lu 3+ , Zn 2+ , and Nb 5± )≤100 cat %.
4. The optical glass according to claim 1 , wherein
a refractive index at a d-line is 2.20 or more and 2.28 or less, and
an Abbe number is 19 or more and 22 or less.
5. The optical glass according to claim 1 , wherein
a glass transition point (Tg) is 705° C. or less.
6. An optical element comprising:
an optical glass comprising:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,
wherein B 2 O 3 is not contained in the optical glass.
7. The optical element according to claim 6 , wherein
the optical element is any one of a lens, a prism or a mirror.
8. An optical instrument comprising:
an optical element, wherein
the optical element is the optical element according to claim 6 .
9. The optical instrument according to claim 8 , wherein
the optical instrument is a camera, and the optical element is a lens.
10. A method for manufacturing an optical glass using a containerless solidification method, the method comprising:
levitating a glass material with a levitation gas, wherein the glass material comprises:
La 3+ , Zn 2+ , and Nb 5+ , and optionally Ti 4+ , Gd 3+ , Y 3+ , Yb 3+ , and/or Lu 3+ , wherein expressed as cation %, La 3+ , Zn 2+ , Nb 5+ , and Ti 4+ satisfy:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
20 cat %≤Nb 5+ ≤60 cat %; and
0 cat %≤Ti 4+ ≤40 cat %,
wherein B 2 O 3 is not contained in the glass;
heating and melting the levitated glass material to obtain a melt; and
cooling and solidifying the melt in a state where the melt is levitated.
11. The method for manufacturing an optical glass according to claim 10 , wherein the optical glass material satisfies:
10 cat %≤La 3+ ≤20 cat %;
20 cat %<Zn 2+ ≤60 cat %;
30 cat %≤Nb 5+ ≤60 cat %; and
Ti 4+ =0 cat %.
12. The method for manufacturing an optical glass according to claim 10 , wherein
the optical glass material satisfies
60 cat %≤(Total amount of La 3+ , Gd 3+ , Y 3+ , Yb 3+ , Lu 3+ , Zn 2+ , and Nb 5+ )≤100 cat %.