Optical design of a light-emitting diode lamp for a maritime lighthouse

Traffic signaling is an emerging field for light-emitting diode (LED) applications. This sustainable power-saving illumination technology can be used in maritime signaling thanks to the recently updated norms, where the possibility to utilize LED sources is explicitly cited, and to the availability of high-power white LEDs that, combined with suitable lenses, permit us to obtain well-collimated beams. This paper describes the optical design of a LED-based lamp that can replace a traditional lamp in an authentic marine lighthouse. This source recombines multiple separated LEDs realizing a quasi-punctual localized source. Advantages can be lower energy consumption, higher efficiency, longer life, fewer faults, slower aging, and minor maintenance costs. The proposed LED source allows us to keep and to utilize the old Fresnel lenses of the lighthouse, which very often have historical value. (C) 2015 Optical Society of America