Overview
ISO 10110-18:2018 - Optics and photonics: Preparation of drawings for optical elements and systems - Part 18 defines standardized drawing indications and tolerances for material imperfections in optical components. It covers four key imperfection categories: stress birefringence, bubbles and inclusions, refractive-index homogeneity, and striae. The standard clarifies how to specify these tolerances on drawings for finished parts, finished assemblies, or raw material blanks used to manufacture optical parts.
Key topics and requirements
- Scope of specification
- Tolerances may apply to a finished optical element, a finished optical system, or the raw material.
- Four defect categories
- Stress birefringence: notation and principles for indicating acceptable residual stress-induced birefringence.
- Bubbles and inclusions: grading, accumulation and concentration rules, and examples of acceptable bubble sizes/counts.
- Homogeneity: refractive-index homogeneity classes and the new focus term for defining measurement focus.
- Striae: density classes and a newly added wavefront deviation method to limit striae-induced wavefront errors; supports multi-directional specifications.
- Notation and drawing practice
- Standardized indication codes and structured notation for drawings (examples: “0/”, “1/”, “2/” to specify finished parts; “00/”, “01/”, “02/” for raw material; “10/”, “11/”, “12/” for assemblies).
- Table and drawing field rules for including material tolerance information.
- Updates and technical changes
- Consolidates and replaces previous Parts 2, 3 and 4 of ISO 10110.
- Introduces wavefront-deviation specification for striae, adjusted bubble concentration rules (counting maximum-size bubbles), multi-directional striae notation, and the homogeneity focus term.
- Informative guidance
- Annexes provide background and practical guidance: stress optical constant, glass guidance for stress birefringence, bubble grades, homogeneity, and striae.
Applications and users
ISO 10110-18 is used by:
- Optical designers and drawing authors for unambiguous specification of material quality on optical drawings.
- Optical manufacturers, glass suppliers and procurement teams to communicate and verify raw material or finished-part tolerances.
- Quality, metrology, and inspection engineers for acceptance criteria and test planning (interferometric and visual tests).
- Systems integrators who must specify allowable material defects in assemblies.
Practical benefits:
- Reduces ambiguity in optical drawings.
- Aligns suppliers and manufacturers on acceptance criteria.
- Helps ensure system-level performance by controlling material-induced optical errors.
Related standards
Keywords: ISO 10110-18:2018, stress birefringence, bubbles and inclusions, homogeneity, striae, optical materials, drawing indications, tolerances, optics and photonics.