Product Code: ILSC2007_1502

Source Size Determination for Extended-source Lasers
Authors:
E. Christopher Brumage, US Army CHPPM; APG MD USA
Wesley Marshall, US Army CHPPM; APG MD USA
Presented at ILSC 2007

Although the potential for viewing hazardous diffuse reflections from high-power lasers is ever present in research laboratories and industrial settings using open-beam, high-power lasers, low-power, extended-source lasers are rare. Lasers formed from a laser diode and a collimating lens or a laser formed by re-collimating a diffuse source comprise most of the extended-source laser products, and the output power or energy per pulse is often barely over the Class 1 accessible emission limit (AEL). Accurate assessment of the hazards from these types of systems is involved since the maximum permissible exposure (MPE) directly depends on the angular subtense of the source, which changes with the distance from the laser where an individual may be exposed. Consequently, the MPE becomes a function of distance from the laser. It is common knowledge that magnifying optics can often increase the hazards for intrabeam viewing of lasers; however, the angular subtense of the source is magnified when optical viewing devices are used to examine an extended laser source. Methods are presented which will allow the angular subtense of the source to be determined at any distance from an extended-source laser with or without the use of telescopic viewing aids.