The radiance of the sun, a 1 mW laser pointer and a phosphor emitter

Abstract

The upcoming new edition of IEC 60825-1 allows to treat the light output which replaces traditional light sources by laser powered emissions, and that do not exceed a certain radiance, to be assessed under IEC 62471 (the lamp safety standard series). Since lamps (at distances where they can be hazardous) are all extended sources, the exposure and emission limits for the retina are specified in terms of radiance. Radiance has very attractive properties for extended sources, but is not intended to be applied to characterize point sources.During the discussion in the standard committee TC76, the level of radiance of a 1 mW laser pointer (which is known to be safe) was discussed. However, the calculation of radiance for safety purposes needs to consider a proper choice of source size and averaging due to the small beam diameter. The concept of radiance is discussed as applied to the sun, a 1 mW laser pointer and a laser illuminated phosphor, as well as the current and new exposure limit for broadband radiation.The upcoming new edition of IEC 60825-1 allows to treat the light output which replaces traditional light sources by laser powered emissions, and that do not exceed a certain radiance, to be assessed under IEC 62471 (the lamp safety standard series). Since lamps (at distances where they can be hazardous) are all extended sources, the exposure and emission limits for the retina are specified in terms of radiance. Radiance has very attractive properties for extended sources, but is not intended to be applied to characterize point sources.During the discussion in the standard committee TC76, the level of radiance of a 1 mW laser pointer (which is known to be safe) was discussed. However, the calculation of radiance for safety purposes needs to consider a proper choice of source size and averaging due to the small beam diameter. The concept of radiance is discussed as applied to the sun, a 1 mW laser pointer and a laser illuminated phosphor, as well as the current and new exposure limit for broadband radiation.