Optical Surfaces Ltd. (OSL) has produced its Practical Guide to Surface Quality - the second in a series of practical guides for optics users.
The informative new 12-page guide is written to enable scientists and engineers better understand an optics quoted surface quality as surface imperfections are typically the most misunderstood, misinterpreted, and ambiguous of all optical specifications.
Key reasons why surface quality is an important consideration in selecting optics are associated with cosmetic acceptability and often more importantly with the functionality / performance of the component. The presence of defects on the surface of an optical component can scatter light which in some circumstances may affect its performance.
The OSL illustrated surface quality application guide includes an introduction to commonly used surface quality terms such as 'scratch' and 'dig' as well as providing definition of the MIL spec, ISO 10110 and DIN 3140 standards. Detailed information is provided on practical applications of the U.S military MIL spec and international ISO 10110 standards. Further a comparison is provided between these two standards to illustrate the different ways in which they describe surface quality in a consistent manner. Finally the guide details typical application for different quoted scratch/dig surface qualities from 80/50 (commercial grade optics, commonly acceptable standard for imaging applications) right through to 10/5 (High precision optics, used for the most demanding high power laser applications).