BMW continues to develop new technology with some of that research centered on the headlight. On the motorcycle side, BMW recently showed off Daytime Riding Lights to increase motorcycle visibility on the Advanced Safety Concept and the Adaptive Headlight to see into turns on the K1600GT/GTL. On the automotive side, BMW introduced full LED headlights on the 6 series, the High-Beam Assistant to automatically turn on and off the high-beams, and Dynamic Light Spot which uses the marker lights to spot light pedestrians.
Laser light is the next logical step in car light development after LED lighting technology. Laser lighting may sound dangerous but this type of lighting is completely safe. It’s already in use in a variety of consumer products, though in many cases it’s a product feature that goes unnoticed by the consumer. One of the reasons it’s safe is that before the light from the tiny laser diodes is emitted onto the road, the originally bluish laser light beam is converted by means of a fluorescent phosphor material inside the headlight into a pure white light which is very bright and pleasant to the eye.
BMW engineers see laser lighting as a way to facilitate new light functions to increase safety and comfort. By definition, laser lighting is radically different from sunlight, and also from the various types of artificial lighting in use today. For a start, laser lighting is monochromatic, which means that the light waves all have the same length. And it is also what is known as a “coherent” light source, which means that its waves have a constant phase difference. As a result, laser lighting can produce a near-parallel beam with an intensity a thousand times greater than that of conventional LEDs. The high inherent efficiency of laser lighting means that laser headlights have less than half the energy consumption of LED headlights. Whereas LED lighting generates around 100 lumens (a photometric unit of light output) per watt, laser lighting generates approximately 170 lumens.
Another feature of laser technology is the size of the individual diodes. With a length of just ten microns (µm), laser diodes are one hundred times smaller even than the small, square-shaped cells used in conventional LED lighting, which have a side length of one millimeter. This opens up all sorts of new possibilities when integrating the light source into the vehicle. The BMW engineers have no plans to radically reduce the size of the headlights however, although that would be theoretically possible. Instead, the thinking is that the headlights would retain their conventional surface area dimensions and so continue to play an important role in the styling of a BMW, while the size advantages could be used to reduce the depth of the headlight unit and so open up new possibilities for headlight positioning and body styling.
The size and efficiency of laser light means it can be used to implement all the familiar current BMW lighting functions as well as develop completely new functions, which will have only minimal power consumption requirements. With the efficiency of laser lighting it’s not surprising that BMW is first showing off this technology in their sustainable BMW i sub-brand and in their premium BMW i8 Concept. Size and efficiency are an even bigger consideration on motorcycles, so it’s possible we’ll see this technology on two-wheels in a few years.