K9L Positive Meniscus Lenses, Uncoated/AR350-1700nm
Tuniu Optics positive meniscus (convex-concave) lenses are thicker at the center than at the edge and can converge light rays. This type of lens is designed to minimize third-order spherical aberration. It is often used in combination with other lenses to shorten the focal length and increase the numerical aperture (NA).
When focusing a collimated beam, the convex side of the lens should face the light source to achieve minimum spherical aberration. Since the curvature of the concave surface of a positive meniscus lens is greater than the radius of the convex surface, it can form real images.
H-K9L is one of the most widely used optical glasses for manufacturing high-quality optical components. When the extra advantages of UV fused silica — excellent transmittance in the ultraviolet range and low thermal expansion coefficient — are not required, H-K9L is the preferred material.
Parameters
| Material | H-K9L optical glass |
| Irregularity (P-V) | λ/4@632.8 nm |
| Design Wavelength | 587.6 nm |
| Surface Quality | 40-20 |
| Diameter Tolerance | + 0.0/- 0.1 mm |
| Center Thickness Tolerance | ± 0.1 mm |
| Focal Length Tolerance | ± 1 % |
| Centering Tolerance | ≤ 3 arcmin |
| Clear aperture | > 90% |
| Bevel | 0.2 mm x 45° |
| Coating | Uncoated, Ravg < 0.5%@350~700 nm, Ravg < 0.5%@650~1100 nm, Ravg < 0.5%@1050~1700 nm |
Model
| Dia., mm | Focal Length, mm | Coating |
| Φ25.4 | 100/125/150/200/300 | Uncoated, Ravg < 0.5%@350~700 nm, Ravg < 0.5%@650~1100 nm |
| 100/125/150/200/300 | ||
| 125/150/200/300 | Ravg < 0.5%@1050~1700 nm | |
| Φ50.8 | 100/150/200/250/300 | Uncoated, Ravg < 0.5%@350~700 nm, Ravg < 0.5%@650~1100 nm, Ravg < 0.5%@1050~1700 nm |