A lens that has one convex surface and the other concave
There are Positive Meniscus Lens and Negative Meniscus Lens
Positive lens (Convergent lens)
A lens with real focus (f and f' ＞ 0)
1/r1 ＞ 1/r2
Center thickness ＞ Edge thickness
Primarily for use in illumination system
Manufacturing Tolerances
| Attribute |
Commercial |
Precision Standard |
| Diameter (Φ) |
+0/-0.5 |
+0/-0.25,+0/-0.15 |
| Effective Focal Length (f') |
±5% |
±2%,±1% |
| Irregularity of Fringes |
1-5,1-2 |
1-2 |
| Surface Quality |
λ/2,λ/4 |
λ/10 |
| Cosmetics (Scratch-dig) |
80-50,60-40 |
20-10 |
| Center Thickness (t) (mm) |
±0.25 |
±0.20,±0.15 |
| Centering Error (arc min) |
3,2 |
2,1 |
| Clear Aperture |
90% of diameter |
90% of diameter |
| Bevel |
Find ground and beveled |
Find ground and beveled |
| Coating |
See attached coating chapter |
See attached coating chapter |
Negative Lens (Spreading Lens)
A lens with Virtual focus (f and f' ＜ 0)
1/r1 ＜ 1/r2
Center thickness (t) ＜ Edge thickness (t')
Manufacturing Tolerances
Attribute |
Commercial |
Precision Standard |
Diameter (Φ) |
+0/-0.5 |
+0/-0.25,+0/-0.15 |
Effective Focal Length (f') |
±5% |
±2%, ±1% |
Irregularity of Fringes |
0.5 |
0.2-0.5 |
Surface Quality |
λ /2, λ /4 |
λ/10 |
Cosmetics (Scratch-dig) |
80-50,60-40 |
20-10 |
Center Thickness (t) (mm) |
±0.25 |
±0.20, ±0.15 |
Centering Error (arc min) |
3,2 |
2,1 |
Clear Aperture |
90% of diameter |
90% of diameter |
Bevel |
Find ground and beveled |
Find ground and beveled |
Coating |
See attached coating chapter |
See attached coating chapter |
|
Focal Length: f= -R / (n-1)
n: refractive index
R: radius of curvature
All sizes and coating are available upon request. |
All dimensions are in mm unless otherwise specified.
Different material, sizes, tolerance and coating are available upon request.
