0/ Stress birefringence

Code 0/ limits the stress birefringence of the glass: the optical path difference between two orthogonal polarizations, per centimetre of path through the part. It is a material requirement and is written in the material field of the drawing table.

Standard: ISO 10110-18:2018

Decode a callout →Use it in a drawing →Build a 0/ callout

Syntax

0/A	A = max. optical path difference between orthogonal polarizations, in nm/cm.
00/A	The same requirement applied to the raw material (the glass maker’s certificate is accepted as proof).
10/A	The same requirement applied to the finished assembly.

Worked examples

0/ 10	≤ 10 nm/cm in the finished part.
0/ 2	≤ 2 nm/cm in the finished part, a tight value for polarization-sensitive optics.
00/ 20	≤ 20 nm/cm in the raw material.

Click an example to open it in the decoder.

Common values and typical grades

2 nm/cm	polarization and interference instruments
5 nm/cm	precision optics, astronomical instruments
10 nm/cm	photographic and microscope optics
20 nm/cm	magnifiers, viewfinders, eyepieces

Commonly cited application guidance (ISO 10110-18 Annex B table) verify.

Common mistakes

Writing a unit or a percentage after the number. The unit nm/cm is implied: 0/ 10, not 0/ 10 nm.
Using 0/ when only the raw glass matters. If the glass maker’s certificate is enough, 00/ says so.
Asking for 2 nm/cm on a part that is not polarization-sensitive. Tighter annealing costs money and lead time.

Questions

What does 0/ 10 mean on an optical drawing?

The finished part may show at most 10 nm of optical path difference between orthogonal polarizations per centimetre of path (ISO 10110-18).

What is the difference between 0/ and 00/?

0/ applies to the finished part; 00/ applies to the raw material, where the glass maker’s certificate is accepted as proof; 10/ applies to a finished assembly.

Sources

ISO 10110-18:2018 (stress birefringence; replaces ISO 10110-2). Full list and edition status: Sources & editions.

An unofficial summary written from public previews of the standards and reputable secondary sources. It does not reproduce the ISO text. Items marked verify could not be fully confirmed. Check against the current edition; see Sources & editions.