Design and prototyping of highly-collimated long-distance optical systems with an LED light source

Electrical lighting design is usually based on the illumination design. Its main task is to ensure that the electricity and optical system can be normal, safe, reliable, and economically viable. In this paper, we propose a design and optimization method for outdoor illumination systems to generate relatively powerful light beams for far distances. The illumination systems are based on highly integrated LED modules instead of high intensity discharge lamps. The size of the LED light-emitting surface is 2.5mm×2.1mm, and the secondary optical elements are composed of a basic plano-convex lens and a Fresnel lens. The results of simulation demonstrate that the emission angle of the system is 1.1°, and the central illumination at 2500 m away is more than 1 lx. The total system is simple but practical, and several groups can be combined into a larger system. Two proof-of-concept prototypes producing acceptable illuminance are developed, and one is composed of four groups whose light is visible from 5000 m away. Both are fully waterproof and in a high degree of protection. The systems can provide up to 12 h of continuous lighting, and the operating temperature rise is less than 25°C. The results indicate that our design can be applicable for practical wild working sites.