Product Code: ILSC2007_1402

Laser Hazards from Pulsed Lasers
Authors:
Wesley Marshall, US Army CHPPM; APG MD USA
Presented at ILSC 2007

Determining the correct maximum permissible exposure (MPE) when a laser is pulsed becomes complex when the laser output beam consists not of regularly spaced pulses of short duration (tens of nanoseconds) and a moderate pulse repetition frequency (PRF), but instead consists of pulse groups that contain several short pulses of a few nanoseconds, or even shorter duration, inside of a macro-pulse that could last for tens of microseconds or even milliseconds. The structures of pulse trains are becoming ever more complicated in that groups of macro-pulses are sometimes repeated at a periodic rate. Determining the correct MPE to use can be involved, when not only the PRF must be taken into account, but also the group PRF, and sometimes even the PRF of the groups of pulse groups. Methods are presented for determining the correct MPE according to the ANSI Z136 standard when these complicated pulse trains are emitted from a laser product.