Metallic coated optics are among the most fundamental types of mirrors used in the photonics market. With a very broad reflectivity range and low chromatic dispersion, they provide the perfect solution for numerous applications.
The reflectance levels of mirrors coated with metals change very little throughout extremely wide spectral ranges. Metallic coated mirrors have a low reflectivity dependence on polarization. Furthermore, metal-coated mirrors are excellent for ultrashort-pulse applications for which dielectric coated optics struggle to reach the required ultrabroad bandwidths. On top of that, metal mirrors show weak chromatic dispersion, making them even more relevant when considering ultrafast applications. However, dielectric optics should be considered for applications that require high LIDT and reflectivity levels.
Our aluminum, silver and gold-coated optics come in different shapes and forms:
- Custom-designed parts (CNC machining available)
- Prisms (various types)
- Parabolic off-axis mirrors (custom off-axis angles possible)
- Cylindrical mirrors (dimensions according to your requirements)
- Spherical and flat mirrors (Ø5- Ø200 mm)
Gold coating provides excellent reflectivity over the infrared region, while silver exhibits the highest reflectivity over the visible and near-infrared regions. Aluminum has the best reflectivity in the ultraviolet region, so is mostly chosen when the applications cover the UV and VIS ranges. All of the coatings mentioned can be applied either with or without a protective layer. A dielectric SiO2 protective layer ensures that the scratch-sensitive metal layer is not damaged and is protected from oxidation. A protective layer can also be used to optimize reflectivity in the desired range or for certain polarizations. For example, UV-enhanced aluminum mirrors have a protective layer to maximize reflectance in the UV.
Overall, metallic coated optics are versatile, cost-efficient and highly customizable. All of these things together can be met by an experienced Altechna team, transferring your ideas into reality.