Optical Windows
Optical windows are transparent components made of materials like glass or crystal that are used to protect and control the flow of light in optical systems. IR windows and optics for use in FTIR Spectroscopy and CO2 lasers. This includes discs, rectangular plates and various other geometries.
In various fields, optical windows serve many purposes. They act as protective barriers, shielding sensitive optical components from environmental factors such as dust, moisture, and contaminants. Additionally, they enable the transmission of light while minimizing distortion, reflection, and absorption, thus maintaining the integrity of the optical system.
Optical windows are employed in a wide range of applications, including scientific research, industrial manufacturing, aerospace, defense, and telecommunications. They are utilized in optical instruments like cameras, microscopes, telescopes, lasers, and sensors. By providing a stable optical interface, optical windows facilitate accurate measurements, imaging, and analysis of light, enabling advancements in numerous fields.
Optical windows come in many shapes and sizes but a major factor is their material. The types of materials that an optical window is constructed from dictate the wavelengths (measured in nm) that they can view. In IR It is extremely important that selecting the right material is done to avoid many a headache and a waste of money and time.
If you are having choice fatigue and are getting overwhelmed by all the options please check out our optical window guide.
Magnesium Fluoride (MgF2) Windows
Magnesium Fluoride (MgF2) Windows
Magnesium Fluoride or MgF2 has a superior transmission range of 120nm to 7μm, which covers all the way from the deep UV into the midwave-IR range.
Being one of the hardest fluoride materials, MgF2 is ideal for use in adverse, humid conditions and can withstand laser and chemical damage. This is a superior choice to other broadband materials like KBr , which also has good broadband tranmission coverage, but is hygroscopic and deteriorates in wet conditions.
Even with no optical coatings, MgF2 features a low surface reflectance and exceptional transmission.
If you do not see the configuration that you are looking for please contact us at info@firebirdoptics.com for a custom quote.
Magnesium Fluoride (MgF2) Specs:
Transmission of uncoated MgF2 windows:
General specs:
| Wavelength range: 1.2-8µm | Coating: Uncoated |
|---|---|
| Diameter tolerance: ±0.2mm | Surface Quality: 60/40 |
| Thickness tolerance: ±0.1mm | Paralellism: <1 arc minute |
| Clear Aperture: 90% | Density: 3.18g/cm3 | Melting point: 1255ºC | Young's Modulus: (GPa): 138 | Coefficient of Thermal Expansion: 13.7x 10-6/°C | Knoop Hardness: 415kg/mm2 |
Expanded Magnesium Fluoride Properties:
| Chemical formula | MgF2 |
|---|---|
| Crystal Class | Tetragonal, Rutile structure | Molecular Weight | 62.32 | Density, g/cm3 at 300 K | 3.1766 | Dielectric Constant for 9.37 x 109 Hz at 300 K | 4.87 | Melting Temperature, K | 1528 | Thermal Conductivity, W/(m K) at 293 K | 21 | Bandgap, eV | 10.8 | Solubility in water | None | Mohs Hardness | 4 | Shear Modulus, GPa | 54.66 | Bulk Modulus, GPa | 101.32 | Poisson's Ratio | 0.276 |
Refractive Index of MgF2:
| µm | No |
|---|---|
| 2.0 | 3.456 |
| 4.0 | 3.429 |
| 6.0 | 3.424 |
Further Reading:
Finding the right optical window can be an exercise in choice fatigue. Let us help!