Alfa Chemistry uses the colorless and durable crystalline material magnesium fluoride (MgF2) to customize infrared optics that can transmit into the MWIR region, with primary applications falling into the VUV and UV regions. All custom MgF2 optics are rigorously tested by skilled experts in a cutting-edge metrology facility, giving customers the peace of mind that their needs will be met. Please contact us as soon as possible to provide you with customer service!
Our Services
Alfa Chemistry offers a quality service for custom MgF2 optics, including windows, lenses and prisms, manufactured to customer's custom specifications. We can provide both coated and uncoated options, including broadband translucency augmentation coating. The table below lists our typical manufacturing requirements. If your requirements are not mentioned below, please contact our technical team and they will guide you through your inquiry.
MgF2 Windows
| Diameter Range | 5 mm ~ 500 mm |
| Diameter Tolerance | ± 0.1 mm |
| Centre Thickness | up to 30 mm |
| Centre Thickness Tolerance | ± 0.05 mm |
| Clear Aperture | 90% |
| Centration Tolerance | 1 arc minute |
| Form Error | better than λ/4 (633nm) over aperture |
| Surface Radius Tolerance | 1 fringe over aperture |
| Linear Dimension | up to 50 mm |
| Linear Tolerance | ± 0.1 mm |
| Angular Tolerance | 5 arc minutes |
| Edge Finish | ground, blacked |
| Chamfer | 0.3x0.3@45° |
| Surface Quality | 20-10 scratch/ dig |
MgF2 Prisms
| Length of Hypotenuse | up-to 50 ± 0.1 mm |
| Length of Sides | up-to 50 ± 0.1 mm |
| Thickness | 30 ± 0.05 mm |
| Angle Tolerance | better than 1 arc minute |
| Edge Finish | ground, blacked |
| Clear Aperture | 90% of entrance dimensions |
| Chamfer | 0.3x0.3@45° |
| Form Error | better than λ/4 (633nm) over aperture |
| Surface Quality | 20-10 scratch/dig |
MgF2 Ground Blanks
| Diameter Range | less than 5 mm to 50 mm |
| Diameter Tolerance | better than ± 0.5 mm |
| Centre Thickness | up to 30 mm |
| Centre Thickness Tolerance | better than ± 0.5 mm |
| Clear Aperture | 90% |
| Linear Dimension | up to 50 mm |
| Linear Tolerance | better than ± 0.5 mm |
| Angular Tolerance | better than 10 arc minutes |
| Edge Finish | fine ground N6 |
| Chamfer | 0.3x0.3@45° |
Applications:
- Roxone Polarized Lenses: Because MgF2 is mildly birefringent, it is frequently used as the substrate in Rochon polarizers, which are constructed from two birefringent prisms.
- Reduction Plates: MgF2 is also utilized as a substrate for delay plates like quarter-wave plates because of its birefringence.
- Excimer Lasers: MgF2 can be ttransmitted to vacuum ultraviolet light (VUV). MgF2 will cut for excimer applications in a manner that generates less birefringence. Together with calcium fluoride, it is frequently employed as a substrate for excimer laser reflectors.
MgF2's Optical Properties
MgF2 is a UV to IR transmissive material widely used in UV wavelength applications. Natural birefringence, mechanical shock resistance, low absorption, chemical stability, water resistance, and thermal shock resistance are only a few of its many advantageous traits. The vacuum UV spectrum exhibits extremely high transmission for MgF2. It can be cut in different directions to generate little or maximum birefringence, depending on its intended application. It can be used to create polarized wave sheets due to its birefringence. Since MgF2 is the toughest fluoride material utilized in optical components, it is frequently used whenever durability is needed, especially in challenging environments.
Fig 1. Refractive properties of magnesium fluoride. (Dodge M. J, et al. 1984)
Below is a quick description of MgF2's optical characteristics. For more information on the properties of MgF2 materials please click here.
| Transmission Range | 0.12 to 7 µm |
| Refractive Index | 1.413@0.22 µm |
| Melting Point | 1255 ℃ |
| Density | 3.18 g/cm3 |
| Hardness | Knoop 415 |
If you need technical advice, please contact our technical team to learn more about our high-quality services.
Reference
- Dodge M. J, et al. (1984). "Refractive Properties of Magnesium Fluoride." AApplied Optics. 23(12): 1980-1985.