Safety aspects of laser displays

Lasers have been used for entertainment almost since their first practical operation reported in 1960. Laser displays started in 1973. There is no doubt that the uses of lasers for entertainment are impressive. However, there are a number of safety issues. Laser displays consist of two types of visual effects: beams and graphical images. A particular show may consist of either or both effects. This application of laser technology is unique in that the laser radiation is not contained. Therefore, the approach to laser safety is often considered different to, for example, materials processing applications. However, the use of a systematic hazard identification process which considers the laser display itself as a modular product can be used. This is also considered as a function of the life cycle of the product. Once the hazards are identified, the adequacy and appropriateness of control measures can be investigated. This can be followed through to an assessment of the risks. A particular safety issue concerns audience scanning, where laser radiation is intentionally scanned through areas occupied by members of the audience. This effect presents particular problems and the hazard should always be quantified. In order to achieve this a detailed knowledge of the parameters of the laser radiation are required.