On the exposure limits for extended source multiple pulse laser exposures

The proposed revisions to the ANSI Z136, ICNIRP, and IEC 60825-1 laser exposure limits for multiple pulse ocular exposure for wavelengths from 400 to 1400 nm are examined for pulse durations tp≥tmin (Ti). The three rules that are defined to be applied for multiple pulse exposures (or for classification for IEC 60825-1) are compared to identify criteria for which one of the rules is the critical one, i.e., the rule that limits the energy per pulse for a given exposure or product emission. Such a comparison can help to simplify a safety analysis, but also guide the design of systems for which the output is to be maximized yet still be classified as a Class 1 or Class 2 laser system.