|Material||Vacuum-Grade UV Magnesium Fluoride|
|Wavelength Range||200 nm - 6 μm|
|Diameter Tolerance||+0.00/-0.10 mm|
|Thickness Tolerance||±0.2 mm|
|Focal Length Tolerance||±2% at 633 nm|
|Surface Quality||40-20 Scratch-Dig|
|Spherical Surface Power*(Convex Side)||3λ/2|
(Peak to Valley)
|Clear Aperture||>90% of Diameter|
|Alignment of C-Axis||<20 armin|
|Index of Refraction||1.376981 @ 630 nm|
*Much like surface flatness for flat optics, spherical surface power is a measure of the deviation between the surface of the curved optic and a calibrated reference gauge, typically for a 633 nm source, unless otherwise stated. This specification is also commonly referred to as surface fit.
- Wavelength Range: 200 nm - 6.0 μm
- Material: Vacuum Grade MgF2
Thorlabs' MgF2 Plano-Convex lenses are popular for many applications in the UV and IR. These lenses are an ideal choice for applications from 200 nm to 6.0 μm. Magnesium Fluoride is extremely durable in comparison to other materials that reach this far down into the UV or out into the IR. The C-axis is oriented to minimize birefringence.
Plano-Convex lenses have a positive focal length and approach best form for infinite and finite conjugate applications. These lenses focus a collimated beam to the back focus and collimate light from a point source. They are designed with minimal spherical aberration and have a focal length which can be calculated using a simplified thick lens equation:
where n is the index of refraction and R is the radius of curvature of the lens surface. To minimize the introduction of spherical aberration, a collimated light source should be incident on the curved surface of the lens when being focused and a point light source should be incident on the planar surface when being collimated.
Plano-Convex Lens kits are also available - please click here for information.