Because MgF2 has an ideal refractive index (1.35@550nm) and high durability, it is commonly used for AR coatings on lenses, windows and beamsplitters.
The single-layer AR coating can be used at almost any angle of incidence and for all wavelengths from UV to IR.
A layer of MgF2 coated on the Fused Silica substrate reduces the surface reflectance to less than 1.5% per side over a wide range.

V-Coating is a multi-layer AR coating that reduces surface reflectivity to less than 0.25% at a 0 degree angle of incidence of a single selected wavelength.
Excellent transmittance can be achieved by applying V-Coating to Fused Silica.
3L System Co., Ltd. provides V-Coating in all wavelength bands from 193nm to 2940nm.

Double-V AR Coating provides the performance of V-Coating at two selected wavelengths.
This coating is useful for optics that transmit visible light aligned lasers as well as NIR beams (eg Nd:YAG Lasers).
Double-V AR Coating has an average reflectance of less than 0.25% in the NIR region and less than 0.5% in the visible region for general AOI.

BBAR coatings provide minimal reflectance over a wide spectral range.
Average reflectance loss is reduced to less than 0.5% per surface over the specified wavelength range.
BBAR coatings are more difficult to coat than single-layer AR coatings because of the large number of coating layers, and they are sensitive to the angle of incidence.

Laser Line High Reflector coatings provide greater than 99% reflectivity at specific laser wavelengths.
It is also used to construct broadband nose reflective mirrors for multi-spectral applications in addition to common Laser Line coatings.
It is more efficient than metal coating and can be used with laser or broadband sources.

Partial Reflector Coating is used as a laser output coupler at an incident angle of 0 degrees.
To maximize the power/energy ratio, an appropriate output coupler must be selected.
3L System Co., Ltd. provides high quality laser cavity coating to minimize light scattering.

Edge pass coating is characterized by an abrupt transition between the transmittance and reflectance regions.
Long wave pass coatings reflect shorter wavelengths and transmit longer ones.
Short wave pass coatings reflect longer wavelengths and transmit shorter wavelengths.
The cut-on/off wavelength is the wavelength at which the transmittance is 50% of the peak value.

Beamsplitters are used to diverge or combine two beams of light.
Plates are used in most laser applications because of their low absorption.
Cubes are primarily used in low-power applications.
Polarizing beamsplitter coatings provide a highly efficient method of directing a randomly polarized incident laser beam to the “S” and “P” components of the beam for a specific field or wavelength range.

Metallic coating is effective in securing lower reflectance, mechanical durability, and damage threshold than dielectric coating.
The advantages of metallic coating are low cost, ultra-broadband performance, and insensitivity to angle of incidence and polarization.