In poor light conditions, drivers often don’t recognize dangers until it’s too late. This is why most road traffic accidents happen at night. What can be done about this – how can we improve road safety in the dark? One possible answer: a laser light source that produces a sharply focused beam of white light with a high level of intensity and efficiency. This was the idea of Carsten Setzer, head of the Automotive Lamps division at Osram in Munich, and Christian Amann, head of the Lighting Systems department at the BMW Group in Munich. Their goal was to improve the car’s high beam to such a degree that it would provide as good a view of the road as in daylight. Working with their team, they developed such a system: the light source for the world’s first laser headlight.“Two developers assembled the first module in- house – in the boiler room – and built a demo product to show that the system works,” says Christian Amann. “It is possible to produce high-density light sources that are much stronger in efficiency, in luminance, than the previous LEDs. The idea for the laser headlight was born.”
Laser light: good visibility even in the dark
When it came to making the idea a reality, however, the researchers faced a problem: a laser beam produces only single-color light of a certain frequency. A headlight, on the other hand, requires white light, which is a mixture of several colors and cannot be created by any laser. To accomplish this task, the researchers used a clever trick: they focused the light of a blue-emitting laser on a special ceramic that converts part of it into yellow light. Mixing yellow and blue light components allowed them to create a narrow white spot of light with a diameter barely larger than that of the original laser beam.
The system was ultimately integrated into the headlight of a BMW i8, which was launched on the market in June 2014. The researchers fitted the extremely bright high beam with a safety system that automatically switches off the laser headlight in the event of an accident or technical malfunction, to ensure that no blue laser radiation, which is harmful to human eyes, can escape. BMW unveiled the first mass-produced vehicle featuring laser light at the 2015 International Motor Show (IAA) in Frankfurt with the new model of its BMW 7 Series. This light reaches 600 meters and enhances the conventional LED high beam with a range of up to 300 meters.
(Image: by-studio – AdobeStock.com, video: MotorAktion)
