Surface Flatness and Wavefront Error
Surface Flatness Interferograms
Surface flatness describes the deviation between the surface of an optical component and a perfectly flat reference plano surface. Optical filter surface flatness is measured using an interferometer (typically a laser Fizeau interferometer) that represents this deviation as a pattern of light and dark bands known as interference fringes. Interference fringes are a visual representation of the destructive interference that results from the difference in phase between light reflected off the optical filter and the reference flat. Once the interferogram is obtained, post-processing software can be used to create a 3D model of the surface.

Power and Irregularity
Optical filter flatness measurements are composed of two main component properties, power and irregularity (Figure 1). Power refers to a type of spherical curvature that can result in a bowl or dome shape. On the other hand, irregularity refers to any surface deviations that are left after power, tilt, and piston are removed from the interferogram. In many cases, the remaining deviations represent small-scale surface variations, but larger deviations may still be present if irregularity wasn’t controlled during substrate fabrication. Power and irregularity can also be specified as independent surface form properties...more...
 

We Do Custom Filters 
Custom optical filters for any application

View Our Catalog 
Browse our selection of optical filters and fluorescence filter sets

INNOVATIVE ENGINEERING 
Advanced plasma deposition. Precision wavelength control. New metrology techniques. Learn how our thin-film coating technology has enabled the routine production of optical components with performance and prices that were previously impossible.  learn more...

Learning Center
Our technology enables the routine production of optical filters with performance and price characteristics that were previously impossible. These informative white papers help our customers and partners maximize the advantage they gain by using our filters.

Thin film optical coatings. Setting the new standard.
Alluxa is an ISO 9001:2008 certified, ITAR registered, highest performance optical filter and optical coating manufacturer located in Santa Rosa, CA. Founded in 2007 by a team of thin-film deposition veterans; Alluxa's core team brings together decades of expertise and diverse backgrounds in deposition, automation, metrology, and optics.

Alluxa produces its filters with a new class of custom optical thin-film coating equipment designed and built by our team. The combination of our state-of-the-art automation, proprietary control algorithms, and our SIRRUS plasma deposition process allows the world's most difficult filters to be created in a fraction of the time required by other hard coating methods. Our proprietary thin-film optical coating platform allows us to reliably and repeatedly reproduce the same high-performance optical thin films over several different coating runs which translates to consistent performance across all of your systems.

Alluxa is delivering custom solutions to the most challenging optical coating problems at competitive pricing. Learn more about our custom and OEM filter offerings, request a quote, or shop our catalog of in-stock and available optical filters.