Large transmissive optical component
View Patent ↗An optical glass for the manufacture of large transmission optics, such as lenses having a thickness of 100 millimeters or more, comprises 35 to 70 wt.-% SiO 2 , 17 to 35 wt.-% Al 2 O 3 , 3 to 17 wt.-% P 2 O 5 , 0 to 6 wt.-% Li 2 O, 0.5 to 4 wt.-% MgO, 0.5 to 3 wt.-% ZnO, a maximum of 1 wt.-% CaO, a maximum of 0.5 wt.-% BaO, 0.5 to 6 wt.-% TiO 2 , 0.5 to 3 wt.-% ZrO 2 , 0 to 1 wt.-% Na 2 O, 0 to 1 wt.-% K 2 O, a maximum of 1 wt.-% of refining agents (As 2 O 3 , SP 2 O 3 ) and a maximum of 500 ppm of other contaminants. The glass composition may be equal to the composition of the glass ceramic Zerodur® and allows to manufacture large transmission optics in a cost-effective way, has a maximum of transmittance which is in the range of a He—Ne lasers and has a CTE of about 3·10 −6 /K.
1. A transmissive optical component comprising an optical glass comprising (in wt.-%):
SiO 2
35-75
Al 2 O 3
17-35
B 2 O 3
0-5
P 2 O 5
1-17
SnO 2 + ZrO 2 + TiO 2
0.1-8
Na 2 O + K 2 O + Cs 2 O + Li 2 O
0.1-8
CaO + MgO + SrO + BaO + ZnO
0.1-8
Refining agents:
≦1
coloring oxides and
≦1;
other impurities:
said optically transmissive component having a coefficient of thermal expansion in the range between 0° C. and 50° C. being 4.1·10 −6 /K at the most.
2. The component of claim 1 , wherein said optical glass comprises (in wt.-%):
SiO 2
35-70
Al 2 O 3
17-35
P 2 O 5
3-17
Li 2 O
2-6
MgO
0.5-4
ZnO
0.5-3
CaO
≦1
BaO
≦0.5
TiO 2
0.1-6
ZrO 2
0.1-3
Na 2 O
0-1
K 2 O
0-1
As 2 O 3
≦1
Sb 2 O 3
≦1
other
≦0.5.
impurities
3. The component of claim 1 , wherein said optical glass comprises (in wt.-%):
SiO 2
50-60
Al 2 O 3
20-30
P 2 O 5
3-12
Li 2 O
3-4
MgO
0.5-2.5
ZnO
0.5-3
CaO
<1
BaO
<0.5
TiO 2
1.5-3.5
ZrO 2
1-2.5
Na 2 O
0-1
K 2 O
0-1
As 2 O 3 + Sb 2 O 3
≦1
other
≦0.2;
impurities
wherein the component has a true transmittance in the wavelength range between 500 and 750 nanometers which is at least 0.55 for a test body of a length of 100 millimeters.
4. The component of claim 1 , wherein said optical glass comprises a maximum of 500 ppm of any element selected from the group consisting of coloring agents, noble metals and halogenides.
5. The component of claim 1 , wherein said optical glass comprises a maximum of 500 ppm of any element selected from the group consisting of Fe 2 O 3 , PbO, Pt, Rh, Cl − , and F − .
6. The component of claim 1 , wherein said optical glass comprises a maximum of 120 ppm of Fe 2 O 3 .
7. The component of claim 1 , wherein said optical glass comprises a maximum of 80 ppm of Fe 2 O 3 .
8. The component of claim 1 , having a coefficient of thermal expansion in the range between 0° C. and 50° C. being 3.5·10 −6 /K at the most.
9. The component of claim 1 , having a coefficient of thermal expansion in the range between 0° C. and 50° C. being about 3·10 −6 /K.
10. The component of claim 1 , having a refractive index n d in the range of 1.42≦n d ≦1.63.
11. The component of claim 1 , having a refractive index n d in the range of 1.47≦n d ≦1.58.
12. The component of claim 1 , having an Abbe coefficient ν d in the range of 53≦ν d ≦63.
13. The component of claim 1 , having an Abbe coefficient ν d in the range of 57.1≦ν d ≦59.1.
14. The component of claim 1 , having a true transmittance in the wavelength range between 500 and 750 nanometers which is at least 0.55 for a test body of a length of 100 millimeters.
15. The component of claim 1 , having a true transmittance in the wavelength range between 550 and 750 nanometers which is at least 0.7 for a test body of a length of 100 millimeters.
16. The component of claim 1 , having a true transmittance in the wavelength range between 600 und 750 nanometers which is at least 0.8 for a test body of a length of 100 millimeters.
17. The component of claim 1 , having a true transmittance comprising a maximum that is in the wavelength range between 600 and 750 nanometers.
18. The component of claim 1 , having a thickness of at least 50 millimeters.
19. The component of claim 1 , having a thickness of at least 100 millimeters.
20. The component of claim 1 , having a lateral extension of at least 0.5 meters.
21. The component of claim 1 , having a lateral extension of at least 1 meter.
22. The component of claim 1 , which is part of a test optic for an aspheric mirror telescope.
23. The component of claim 1 , being configured as a component selected from the group consisting of a lens and a prism.
24. The component of claim 1 , being configured as a component selected from the group consisting of a lens and a prism and further having a maximum thickness of at least 50 millimeters and a maximum lateral extension of at least 0.5 meters.