BMW i8 Concept live photos, 2011 Frankfurt Auto ShowEnlarge Photo
So might go the "breakup speech" with LED lights, now that BMW has announced it's working on a production version of the laser headlights we saw on the i3 electric concept and i8 plug-in hybrid sports car at September's 2011 Frankfurt Motor Show.
BMW says its laser headlights offer several advantages over the (still fairly new) technology of LED headlights. LEDs are already low-energy, but lasers even more so, and provide carmakers with even greater creative freedom when it comes to styling, since lasers take up so little room.
If you've ever seen a laser pen you'll be aware of the very intense light possible, but also the relatively narrow spread.
BMW doesn't project laser light directly onto the road. Three laser diodes inside the headlamp assembly generate blue laser beams 10 microns wide - about a tenth the thickness of a piece of paper, or a fifth that of thin human hair.
Those narrow beams are aimed at small mirrors, which reflect them onto a lens. Yellow phosphorus inside the lens generates an intense white light, which is then bounced off a reflector onto the road.
Just like LEDs the light can be varied in intensity and shape depending on the configuration of the reflectors, only even more accurately. It's quite possible to have very little "spill" either side of the beam, a fact highlighted by Audi's A2 concept at the Frankfurt show, which could use lasers to project a warning triangle onto the road behind the car as a warning in poor visibility.
BMW still has to work around some issues with the technology, such as its sensitivity to heat and vibration. Even so, BMW expects to make further announcements on its development next year.