Optical Flats

Optical Flat

Optical Flats are most commonly used as test plates to evaluate the accuracy of unknown optical surfaces. Esco manufactures optical flats out of G1 grade fused quartz; the low thermal expansion, abrasion resistance and general stability of this material allows continuous use with minimal degradation over time.

Esco offers optical flats with either one or two precision surfaces. Customers can test flat optical surfaces by holding the precision of an optical flat against the test surface. When placed under a monochromatic light, a fringe pattern can be seen through the back surface of the flat. This pattern describes the contour of the test surface, and is not affected by the accuracy of the rear surface.

  • One Precision Surface
    This optic has one precision polished surface and one ground surface.
  • Two Precision Surfaces
    This optic has two precision polished surfaces and offers its user versatility and an extended lifetime.


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Having been in business for more than 50 years, Esco has witnessed many changes in optics industry, as well as within their own company.

Our Quality

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Our top priority is to provide customers with the highest quality and most accurate optical components in the industry. From standard catalog optics to custom optics, we are committed to manufacturing optical lenses that meet or exceed your specifications.

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custom optics technology


Esco continues to invest in cutting edge technology. Most recently, we've added two Optotech CNC lens machines to our existing four, which allows us to produce a variety of spherical, cynlindrical, and aspherical radius work. 

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