• Single + Dual Wavelength AR Coatings (VAR / DAR):A single wavelength V-coat will provide reflectance less than 0.25% for 0° incidenceor 0.5% for 45° incidence at the chosen wavelength. Dual wavelength coatings will approach the performance of V-coats for two selected wavelengths. They are useful for optics which must transmit a visible alignment laser as well as a UV or near IR process beam. It is also useful for transmission of fundamental and first harmonic wavelengths.
• Broadband-AR-coatings:Anti-reflection coatings are offered to reduce surface reflections to a minimum. Two types of broadband coating are offered. A single layer of MgF2 on Fused Silica or BK7 reduces reflections per surface to about 1.5% over a broad bandwidth. If lower reflectance is required a multilayer broadband coating will provide an average reflectance less than 0.5% per surface.

• Protected + Enhanced Metallic Coatings (PAL / EAL / PAG / EAG / PAU / EAU)

  Metallic coatings make very broad bandwidth reflectors. Usually it is best to protect the coatings with a durable dielectric layer as they are very soft and susceptible to scratching. The efficiency of metallic reflectors falls off at shorter wavelengths but this may be enhanced by the application of a multi-layer dielectric thin film stack. The table shows the reflectance of each of the metals without any protection or enhancement. Protected metallic coatings have a dielectric coating layer over the metallic layer to protect the coating from being oxidized in the air or from scratched. For enhanced metallic coatings, a stack of dielectric layers are added on the metallic coating to increase reflectance for a particular wavelength range.

• Dielectric High Reflective Coatings:

1. Broadband HR coatings provide an average reflectance of 99% over a broad range of wavelengths. These broadband mirrors may be used for white light or multi-spectral applications.
2. Single wavelength, high power HR coatings are suitable for intra and extra cavity use. They provide the ultimate high reflectance of Rs > 99.8% and Rp > 99% for a specific wavelength. They may be used as a rear cavity reflector or for extra cavity use in beam delivery or turning. Note that Lambda high quality visible laser cavity coatings are designed for low scattering.

• Dichroic Beamsplitters – Beam Combiners – Harmonic Separators (SPD / LPD / BC / HHS)

1. Separate or combine beams with different wavelengths:Separate or combine beams with different wavelengths. These dichroic coatings allow one wavelength region to be transmitted while they reflect another region. They may be used as illustrated to separate or combine different wavelengths. This can be useful when working with alignment lasers or frequency doublers.
2. Dichoric Beamsplitters:These long-pass and short-pass coatings may be applied to any optical component to separate or combine different wavelength regions. They are available for normal and 45° angle of incidence. These coatings are highly effective for the wavelength of interest, reflecting over 99%. While they transmit over 85% of other nearby wavelengths, they are not blocked over a broad spectral range.

• Highly Transmissive AR Coatings For FLIR Applications:

Metallic coatings make very broad bandwidth reflectors. Usually it is best to protect the coatings with a durable dielectric layer as they are very soft and susceptible to scratching. The efficiency of metallic reflectors falls off at shorter wavelengths but this may be enhanced by the application of a multi-layer dielectric thin film stack. The table shows the reflectance. of each of the metals without any protection or enhancement. Protected metallic coatings have a dielectric coating layer over the metallic layer to protect the coating from being oxidized in the air or from scratched. For enhanced metallic coatings, a stack of dielectric layers are added on the metallic coating to increase reflectance for a particular wavelength range.

• IBAR : IR Broadband AR Coatings : Coatings for 3-5 µm and 8 – 12 µm bands

Infra-red broadband anti-reflection coatings are offered for the two broad spectral passbands of 3 – 5 µm and 8-12 µm. 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.