BMW develops laser-based headlight technology

September 01, 2011 // By Christoph Hammerschmidt
Following the introduction of the full LED headlight, carmaker BMW regards laser light as the next logical step in the development of vehicle headlight technology. The development is already in an advanced stage, the company said.

BMW said its engineers are already working on the introduction of laser light for series production within a few years. Laser light could facilitate entirely new light functions for more safety and comfort and at the same time contribute significantly through its higher degree of efficiency towards a saving in energy and fuel respectively.

Laser light produces virtually parallel light beams. Thus it is different from sunlight, and also from the various types of artificial lighting in common use today. Because laser light is monochromatic and coherent, laser lighting can produce a near-parallel beam with an intensity a thousand times greater than that of conventional LEDs. In vehicle headlights, these characteristics can be used to implement new functions. Also, the high inherent efficiency of laser lighting means that laser headlights have less than half the energy consumption of LED headlights.

BMW said for safety reasons the light is not emitted directly, but is first converted into a form that is suitable for use in road traffic The originally bluish laser light beam is converted by means of a fluorescent phosphor material inside the headlight into a pure white. Thus, the intensity of the laser light poses no possible risks to humans, animals or wildlife when used in car lighting, the company explained. The resulting bright white light is described it as "very pleasant to the eye" and generated with very low energetic effort.

Laser lighting technology is already in use in a variety of consumer products, though in many cases this is a product feature that goes unnoticed by the customer. That won't be the case when this technology is used in cars, however, as planned by BMW. Here the whole point is that the advantages should be noticeable and visible.

An important 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