Product Code: ILSC2009_1501

In the Safety Limbo: Simultaneous Illumination and Optical Wireless Communications with Light-emitting Diodes
Authors:
Werner Horak, Siemens AG; Munich Germany
Joachim Walewski, Siemens AG; Munich Germany
Presented at ILSC 2009

The high-speed modulation capabilities of white light-emitting LEDs offer a unique combination of illumination and simultaneous free-room data transmission and therewith a series of new and promising applications. However, the optical radiation safety requirements for this dual-use of LEDs are currently separately provided with two different standards: free-space optical communication with LEDs is (still) covered by the application-related part of the laser-safety series, IEC 60825-12, whereas almost all other applications of LEDs, including lighting, are (since 2006) covered by the lamp safety standard IEC 62471. Primarily due to big differences in the underlying safety philosophies, the impacts of both standards to one and the same source are quite different, with the laser-related requirements being most restrictive. However, there seems to be no added hazard for a lamp just by high-speed modulation. A simple exclusion of LEDs also from the scope of IEC 60825-12 would help but not really solve the situation, since the lamp standard does not (yet) provide adequate assessment criteria for pulsed sources. This contribution addresses the different safety issues and tries to provide suggestions for future revisions of the requirements.