In laser safety, what is the term 'beam divergence' defined as?

Beam divergence refers to the phenomenon where a laser beam expands or spreads out as it propagates through space. This characteristic is crucial in laser safety because it influences how the beam behaves over distance, affecting potential exposure to the eyes and skin of individuals in the laser's path. Understanding beam divergence ensures that safety measures can be effectively implemented based on how concentrated or dispersed the beam will be at various distances from the source.

In the context of laser safety, monitoring beam divergence is essential to prevent unintended exposure and to devise appropriate safety protocols and equipment. Different lasers exhibit varying degrees of divergence due to their design, purpose, and beam quality. The knowledge of beam divergence helps in assessing the safe operating distances and in determining necessary protective measures for personnel working near lasers.