Lens
meniscus lens
meniscus lens
Meniscus lens has one side concave ,the other side convex,it include Positive meniscus lens and Negative meniscus lens
If center thickness is thicker than that of edge, the lens is positive meniscus lens;on the other side, the lens is negative meniscus lens.Mensiscus lens can increase the aperture of the positive meniscus lens assembly, without undue increase in the aberrations.
Positive meniscus lens is a convex-concave lens thicker at the center than at the edges. It is used to minimize spherical aberration. When used in combination with another lens, it’s will shorten the focal length, and increase the NA of system.
Negative meniscus lens is a convex-concave lens thinner at the center than edges. It increases the divergence of the beam without introducing any significant spherical aberration. When used in combination with another lens, it will increase the focal length, and decrease the NA of the system.
Specifications
| Material: |
BK7 grade A optical glass |
| Diameter: |
Smallest up to 2mm |
| Diameter Tolerance: |
+0.0, -0.1 mm |
| Paraxial Focal Length Tolerance: |
±2% |
| Tc tolerance: |
±0.1 mm |
| Clear Aperture: |
>85% |
| Surface Quality: |
640-20 S/D |
| Surface Figure: |
N=3, △N=0.5 |
| Centration: |
.±3 arcmin |
| Coating: |
Single layer MgF2 broadband AR coating |
