TS ISO 9211-1

TS ISO 9211-1 is a vocabulary standard for optical coatings, providing the terminology used to describe coating types, functions, imperfections and related terms. In optics and photonics, coatings are applied to component surfaces to modify optical behavior such as reflectance, transmittance, filtering or spectral response. By establishing common language, the standard supports clear communication between designers, manufacturers, test laboratories and users.

How the terminology is organised

The document groups terms into four classes: general terms and definitions; definitions of coatings by function; definitions of common coating imperfections; and other definitions. It also identifies surface treatments of components and substrates by the application of optical coatings, and gives a standard form for their specification. In practical terms, this helps ensure that a coating is described not only as a material layer, but also by its intended optical role and its effect on the treated surface.

Why this vocabulary matters in practice

Vocabulary standards are important in technical documentation because words such as coating, defect, function and specification can be used differently across projects and industries. This standard is intended to support consistent terminology and, where necessary, the description of general characteristics and test and measurement methods. It is not a process standard: it is not intended to define how a coating is made. In broader technical context, optical coatings are widely used on lenses, mirrors, filters and sensor surfaces, where surface quality, spectral performance and defect definition are central to design and assessment.

• Provides common terminology for optical coatings.
• Distinguishes coatings by function.
• Covers common coating imperfections.
• Supports standardised specification of treated components and substrates.
• Excludes ophthalmic optics (spectacles).
• Focuses on terminology and specification rather than process methods.