Home » Optical Components » Metrology


coi-metrology1At Clear Align we have literally hundreds of stock glass tooling called “testplates” that allow optical designers to save both time and money. Each radius in our testplate library comes complete with the testplate used for accurately measuring the radius as well as the various grinders, polishing hubs and other tooling required to make an optic of that radius accurate to 0.2% of the stated radius. The testplate library is available in such popular programs as Zemax, or you can view/download it here:


In addition when a particular radius is not available then we also maintain a Zygo GPI (pictured above) interferometer and radius bench for measuring interferometrically the power and irregularity of any optic produced by our opticians. This data is critical for the production of our optics and also a very useful quality metric for assuring that the optic was made to the specification.

Characteristics we can measure include:

Single lens elements:
Power tolerance
Irregularity Tolerance
Surface roughness
premium inspection lab 029Scratch/Dig (60/40)
Transmission vs. wavelength
Center thickness

Optical assemblies:
Modulation Transfer Function
Effective Focal Length

For measuring other parameters we also use the standard drop gauges, calibers and radius gauges found in most optical shops. We also have invested in a non-contact measurement system that can easily measure diameter, CT, and many surface features so that we do not need to risk the optical surface to provide salient data.