Footer CTA

What Information Is Needed to Specify an Optical Coating?

Several considerations must be taken into account when designing a coating. Providing as much information as you can up front allows us to design the coating with the best performance for your application.

Baseline Information:

Substrate: Are you looking for an optical coating on BK7? Sapphire? Fused Silica? Silicon? We work with a wide variety of substrates and also have relationships with several substrate suppliers if you need us to source them.

Clear Aperture: The clear aperture (CA) determines the area that the coating is applied to. Depending on the CA needed, we can use our conventional tooling or design custom tooling to fixture the optics.

Wavelength Range: Are you working with a single wavelength, wavelength band, or multiple wavelength bands? We can accommodate your coating needs from the UV to MIR.

Transmission or Reflectance: Are you looking for high transmission through your optic (ex: Tavg > 98% 400nm – 700nm) or high reflectance (ex: Rabs > 95% 0.8µm - 12µm)?

Polarization:Is the light source in your optical system polarized? Do you need the coating to improve both s and p polarizations?

Angle of Incidence (AOI) Range: What angle(s) of light will the optic see? Will it be used at one angle such as 0° or 45°? Will it be used over a range of angles such as 0 - 25°?

Surface Quality: Surface quality specifies passable imperfections and is given in terms of scratch/dig. Does your optic require commercial quality (80/50), research quality (40/20), or laser quality (20/10)?

Additional Information:

Environmental Durability: What environment will the optic be used in? MIL-SPEC standards are commonly referenced to identify what requirements need to be met for adhesion, abrasion, humidity, temperature, and other durability specifications.

Laser Damage Threshold: Is your optic being used in a laser system? Is the laser source continuous wave (CW) or pulsed? CW threshold specifications are given in irradiance (W/cm^2) and should specify the wavelength(s) the threshold applies to. Pulsed specifications are given in fluence (J/cm^2) and should specify the wavelength(s), pulse duration (ns, ps, fs), and repetition rate (Hz). Certain materials lend themselves to have higher laser damage thresholds. By providing the laser damage threshold that is required, we can design the coating with the proper materials to best suit the application.

If you don’t have all of this information, or if some of it is not relevant to your application, that is okay.  We can still provide a quote and are happy to discuss your application in more detail.

Click Here to Download