MgF2 window Product
A MgF2 window is an optical window manufactured from crystalline Magnesium Fluoride. This hard, durable optical material lends itself well to use under harsh conditions. It is highly resistant to chemical etching as well as mechanical and thermal shock. It also has a high laser damage threshold.
MgF2 exhibits excellent broadband transmission from 120 nm to 8 μm , from the deep UV to the mid infrared. This makes them a good choice for UV radiation sources and receivers as well as for use at the Hydrogen Lyman-alpha line. They are often used as UV viewpoints, and are a good option for UV polarizers and excimer laser applications. It has a high transmittance between 120 nm and 8 µm, and between 0.4-5.0 µm transmits over 90%.
MgF2 has a melting point of 1255 degrees Celsius. It has a density of 3.177 g/cm3, and a tetragonal crystal type. Our optical windows are typically oriented with the round surfaces perpendicular to the c-axis of the MgF2 crystal to minimize birefringence. Custom random cut MgF2 windows can be manufactured on request.
MgF2 is the only optical material which combines a wide spectral transmission band with birefringence. This birefringence means that the refractive index depends on the polarization and propagation direction of light. Because of birefringence, a MgF2 window can exhibit double refraction, so that a ray of light will be split by polarization into two rays with different paths.
The ray component for which the optical window has a higher effective refractive index is called the slow ray, while the one with the lower effective refractive index is referred to as the fast ray. If a beam enters the MgF2 window from air, the slow ray will be refracted more towards normal.
| Name | MgF2 window |
| Material | Magnesium Fluoride MgF2 |
| Irregularity (fringe) | l/4 |
| Diameter Tolerance | +/- 0.02mm |
| Thickness Tolerance | +/- 0.02mm |
| Clear Aperture | >90% |
| Parallelism | 30 arc sec |
| Surface Quality | 20/10 |
| Wavefront Distortion | l/4 per 25mm |
We can manufacture optical windows in any optical material required. Please contact us with your specific requirements.
