Positive Meniscus & Negative Meniscus Lenses
|
Positive meniscus lenses are designed to minimize spherical aberration and are usually used in small f number applications (f # <2.5). For 2.5 f #<10, meniscus lenses can also improve image quality and reduce spot size. Positive meniscus lenses have greater curvature (shorter radius of curvature) on the convex side and a smaller curvature (longer radius of curvature) on the concave side.
Negative Meniscus lenses are offered as an alternative to other negative lenses and are particularly appropriate for the high index IR materials. They are commonly used in beam expanding applications where minimal spherical aberration is desired. Negative meniscus lenses have greater curvature (shorter radius of curvature) on the concave side and a smaller curvature (longer radius of curvature) on the convex side.
RMI Meniscus Lenses are designed to customers requirements.
Both sides can be coated with an RMI high efficiency narrowband, anti-reflective coating.
|
RMI Standard Spcifications
|
| Materials: |
BK7, UVFS, FS, CaF2, MgF2, BaF2, Sapphire, Si, ZnSe, Ge, Cleartran, All Glass, All Crystals
|
|
Surface Figure:
BK7, UVFS, FS:
CaF2, MgF2, BaF2:
ZnSe, ZnS, Ge, Si, Cleartran:
Sapphire (2 grades):
|
Both Surfaces
λ/10 at 633 nm
λ/4 at 633 nm
λ/20 at 10.6 µm
λ/10, or λ/4 at 633 nm
|
|
Surface Quality:
BK7, UVFS, FS:
CaF2, MgF2, BaF2:
ZnSe, ZnS, Ge, Si, Cleartran:
Sapphire (2 grades):
|
Both Surfaces
10-5
20-10
40-20
20-10 or 60-40
|
|
Diameter Tolerance:
|
+ 0.000", – 0.010"
|
|
Thickness Tolerance:
|
± 0.010"
|
|
Focal Length
Tolerance:
|
± 0.5%
|
|
Centration Error:
|
< 3 arc minutes
|
|
Bevels:
|
0.010" – 0.030" at 45º
|
|
Clear Aperture:
|
Central 85% of diameter
|
|
 |
|
|
|
