A compact optical sensor for risk assessment from high-power laser scattering

The outdoor operation of multi-kilowatt high-power lasers involves the potential hazard of exposing the human eye and skin to scattered radiation. In present laser safety standards and regulations, the effects of atmospheric off-axis scattering and the dynamic interaction between the laser beam and the target object are not adequately represented. Therefore, experimental studies are dedicated to providing quantitative information on scattered radiation for comprehensive laser safety evaluations. With this end in view, a mobile detection system has been developed that relies on the technical specifications (i.e. entrance aperture and field-of-view) of laser safety regulations. The mobile detection system is deployed at the German Aerospace Center (DLR) laser test range at Lampoldshausen. Atmospheric scattering experiments are performed by placing the calibrated detection system under specified scattering angles relative to the direction of the laser beam and determining the scattered radiation, i.e. absolute values for scattered laser power. In addition, the detection system is used for target scattering experiments. In these experiments, the sensor's versatility is demonstrated by measuring the specularly and diffusely scattered laser radiation from metallic target objects. The dependence of the scattering power as a function of the scattering angle, distance, and laser output power is investigated during laser-matter interaction to demonstrate the capabilities of the system.