TS ISO 10110-18

TS ISO 10110-18 is part of the ISO 10110 series for drawings of optical elements and optical systems. It focuses on how tolerances for four classes of material imperfections are indicated on the drawing: stress birefringence, bubbles and inclusions, homogeneity, and striae. In practical terms, it gives designers and manufacturers a common drawing language for specifying optical material quality in a way that can be read consistently across the supply chain.

Separating different kinds of material imperfection

These four categories are technically distinct. Stress birefringence is associated with residual stress in the material and the way that stress changes optical polarization behavior. Bubbles and inclusions refer to discrete foreign phases or void-like features inside the material. Homogeneity concerns the uniformity of refractive index throughout the optical material. Striae are often oriented refractive irregularities introduced during manufacturing. By treating them separately, the standard helps avoid vague material descriptions and makes it easier to compare requirements between drawings.

How the tolerances are applied

According to the scope, the tolerances may be applied to a finished optical part, a finished system of optical parts, or the raw material used to manufacture an optical part. That distinction matters because the quality check can be tied to the final component, the assembled optical set, or the incoming material before fabrication. In general technical context, these indications are important for lenses, prisms, windows and similar optics where internal inhomogeneities can contribute to scatter, wavefront disturbance, or reduced imaging quality. TS ISO 10110-18 is about specifying these internal material characteristics clearly in the drawing, not about inventing a separate material test method beyond the standard’s drawing notation framework.