IR Coatings

Infra-red Broadband AR Coatings

　　- Coatings for 3 - 5 m and 8 - 12 m bands
　　- Coatings for ZnSe or Ge

    Infra-red broadband anti-reflection coatings are offered for the two broad spectral passbands of 3 - 5 m and 8 - 12 m. Coatings are designed for the refractive index of the substrate so it is necessary to offer separate coatings for different substrate materials. Standard coatings are offered for Zinc Selenide and Germanium. These coatings are highly durable and can be cleaned repeatedly using normal optics handling techniques. They are suitable for high power laser use such as that emitted from a CO2 laser.

Infra-red Extra-Broadband AR Coatings

　　- Extra-broadband 2.5 - 13 m bandwidth
　　- Imaging applications

    These extra-broadband coatings work effectively over the entire useful IR optical spectrum from 2.5 to 13 m, except for the silicon coating which works only over the passband of silicon (2.5 - 5 m). They are useful for imaging applications including imaging with dual passband systems. They provide an average reflectance of less than 5% over this range. This does not put them in the category of high performance anti-reflection coatings but when broad bandwidth is essential they provide a good overall transmission. The coatings can be adapted to either normal or 45 incidence so please specify the intended angle of incidence when ordering. It is also helpful if you specify the major wavelength of interest so the coating can be tuned for best performance at that wavelength. These coatings are highly durable and resistant to laser damage and can be used with CO2 lasers. They may be cleaned repeatedly using normal optics handling techniques.

Infra-red Narrowband AR Coatings

　　- Single wavelength and dual wavelength coatings

    These narrow-band coatings are intended for use at a specific wavelength. They are multilayer V-coatings which reduce the reflectance to 0.5% at the center wavelength. Their performance is dependent on polarization, wavelength and angle of incidence. It is important to specify the substrate material as the coating design will vary with refractive index of the substrate. Standard coatings are offered for use on Zinc Selenide and Germanium. The dual wavelength coatings are intended to permit the transmission of a visible alignment beam (usually in the red part of the spectrum). These coatings are highly durable and resistant to laser damage. They may be cleaned repeatedly using standard optical handling techniques.