The effect of liquid droplets on laser safety for consumer products: A numerical model

Abstract

With the popularization of laser products in consumer electronic devices, there is rising concern regarding how adverse environmental effects may affect the laser safety classification for the system. One such concern is how a water or oil droplet in the beam path may focus a diverging light source such that the system is more hazardous compared to its nominal state. This is of particular concern to devices such as phones, flashlights, and decorative laser projectors which will likely be exposed to rain, sweat, or liquid ingress. In this paper, we provide a numerical model to characterize how droplet size, surface energy, and position of the droplet ultimately affect the optical hazard posed by an affected system.With the popularization of laser products in consumer electronic devices, there is rising concern regarding how adverse environmental effects may affect the laser safety classification for the system. One such concern is how a water or oil droplet in the beam path may focus a diverging light source such that the system is more hazardous compared to its nominal state. This is of particular concern to devices such as phones, flashlights, and decorative laser projectors which will likely be exposed to rain, sweat, or liquid ingress. In this paper, we provide a numerical model to characterize how droplet size, surface energy, and position of the droplet ultimately affect the optical hazard posed by an affected system.