Our world class manufacturing facilities are able to produce substrates with surface accuracies of < λ/20, surface qualities of 10-5, parallelism of <0.5 arcseconds, and surface roughness of <5 Angstroms in any glass and most crystalline substrates. According to theoretical calculations, this resonance is located at 8.05 µm in gold, assuming a 148-nm-thick SiO2 protective layer. Just ask our Sales Team for your customized protected gold mirror. Hello, thank you for contacting Thorlabs.
Stanford University. Hi, For assistance with performing similar calculations, we provide a spreadsheet calculator that can be downloaded by clicking the button to the right. This treatment provides an abrasion-resistant surface while maintaining the performance of aluminum mirror. Silver, for instance, has high reflectivity over the visible range of the spectrum, which makes it colorless when white light is focused on the metal.
I will send you separate email with the requested file.
The performance of gold (96% reflectivity from 750 – 1500nm) is maintained, but the optic has a more durable finish. A naive calculation of the average linear power density of this beam would yield a value of 0.5 W/cm, given by the total power divided by the beam diameter: However, the maximum power density of a Gaussian beam is about twice the maximum power density of a uniform beam, as shown in the graph to the right.
Protective overcoat is layered over the gold to help protect it from damage and make cleaning easier. The values specified are conservative, with typical data showing that our mirrors are able to withstand 2-3 times the specified threshold. Dear Sir or Madam, The performance of gold (96% reflectivity from 750 – 1500nm) is maintained, but the optic has a more durable finish. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately [3].
Response from Jeremy at Thorlabs: The exact coating thicknesses are not something that we can provide because it is considered proprietary information. We will discuss the possibility of offering this customization via email. Aluminum (Al) is popular for use in mirrors of visible and infrared varieties, while alloys exist of gold (Au) and silver (Ag) that improve durability and secondary workability. Best regards,
Could you please provide me with reflectivity for the Protected Gold, Protected Silver and Protected Aluminium coatings at 4.62 um and 45° incident angle?
Coatings for use with high-power ultraviolet (UV) lasers are made of different materials from those for use in the visible and near-infrared (IR). King regards, Valery. Sometimes, an unprotected gold mirror is preferred in order to avoid any dispersion from a protective coating; this is possible as gold does not tend to get oxidized. Mirror Reflectivity. Damage threshold specifications are constant for all protected gold coated mirrors, regardless of the size or focal length of the mirror.