How Laser-powered Headlights Work

BMW's i8 hybrid sports car concept was revealed at the 2011 Frankfurt Motor Show. See more pictures of concept cars.
Courtesy of BMW USA

By now you're no doubt aware that lasers are good for so much more than just blowing up Imperial Star Destroyers. Over the years they've developed a lot more down-to-earth, practical uses -- like reading CDs, DVDs and Blu-ray discs, correcting blurry vision and creating dancing dots on the floor for your cat to chase.

Now you can add to that list, "illuminating car headlamps." That's right; vehicle headlights are getting the laser treatment, courtesy of BMW. The high-end German automaker announced the innovation at the 2011 Frankfurt Motor Show, showcasing the technology on its i8 hybrid sports car concept.

BMW says that lasers have an illuminating power 1,000 times more powerful than light-emitting diodes -- or LEDs -- which up until just recently provided the greatest wow factor of all the bulb technologies out there. Thus, BMW says, the laser lights can be much smaller than conventional lighting systems, they can use less energy to operate and well, they look pretty darn cool, too.

But wait a minute, haven't we always been told never to look directly into a laser because it could blind you with its intensity? Should we prepare to be spectacularly annoyed even further by nighttime drivers of fancy cars with overpowered headlights? And what you really want to know: Could the lasers cut through a person like a Star Wars lightsaber if there is an accident?

Truth be told, the technology behind BMW's laser headlamps is pretty ingenious -- and rather tame when it comes to their danger quotient. Read on to find out how these laser-powered headlights work and when they might be shedding light on a stretch of dark pavement near you.

Laser-powered Headlights: Basic Operation

Because of the way the beam energy is directed, then reflected, then ultimately displayed out of the headlight housing, you can't accidentally injure your eyes, according to BMW.
Because of the way the beam energy is directed, then reflected, then ultimately displayed out of the headlight housing, you can't accidentally injure your eyes, according to BMW.
Courtesy of BMW USA

BMW's new headlight technology is powered by lasers, but the important thing to note is that when you look into them, you're not looking at an actual laser.

What happens with each light is that three blue lasers positioned at the rear of the assembly fire onto a set of mirrors closer to the front. Those mirrors focus the laser energy into a lens filled with yellow phosphorus. The yellow phosphorus, when excited by the blue laser, emits an intense white light. That white light shines backward, onto a reflector. The reflector then bounces the more diffused white light forward, shining it out of the front of the headlight casing as a beam that is powerful, yet still able to be gazed upon.

While we tend to think of a Dr. Evil-style laser as probably generating a huge electric bill, BMW says its laser-powered headlights actually save energy compared to other systems. Even though the actual lasers are 1,000 times brighter than LEDs, the system uses only about half the power, according to BMW. That's electric power that can go toward operating the engine, if you're driving a hybrid or full-electric vehicle. That's also less energy to draw from the main battery (though we imagine that any vehicle sophisticated enough to have these would never let you accidentally leave the lights on long enough to need a jumpstart).

Because laser-powered headlights can put out more brightness for their size, the headlamp units themselves can be much smaller. As a result, designers can have a lot more flexibility to make more aerodynamic shapes or fit more stuff into the engine compartment with the freed-up space.

We've heard of aircraft pilots being visually assaulted by knuckleheads on the ground who thought it would be funny to shine laser pointers at them. While some lasers may be fun, intense lasers are not toys when it comes to the safety of our vision. Click to the next page to find out if laser-powered headlights are a traffic incident waiting to happen.

Safety of Laser-powered Headlights

Lasers have without a doubt enabled many modern conveniences. They allow us to check out faster at retail stores. They let us pack impressive amounts of information on a thin plastic disk, then retrieve it -- in the form of an album or full-length movie. We can even use them to enhance our bodies, with skin treatments, laser-assisted eye surgery and many other medical procedures.

But one thing almost everyone knows is that, just as you would with the sun -- you never look directly into the source of a laser beam. Its parallel beams focus so tightly, they can act like a scalpel on your retina -- indeed, lasers are used as precision medical instruments, among their many applications.

That said, BMW maintains that there's no way to blind yourself by looking into one of its laser headlights. Because of the way the beam energy is directed, then reflected, then ultimately displayed out of the headlight housing, you can't accidentally injure your eyes, according to BMW.

So if you did happen to own a BMW with these lights installed, you wouldn't have to worry about hitting an animal or pedestrian because its eyeballs were seared by your headlights.

And what about to our other safety point? The worry about slicing through people or objects with an errant beam if the headlight housing is compromised -- be it by car accident, light getting out of alignment or what-have-you?

BMW says that power gets cut to the lasers if any damage occurs.

Now that you know how laser-powered headlights function -- and that they won't melt your face like you're a bad guy in "Raiders of the Lost Ark" -- perhaps you're wondering how and when you can own a set. For the answer, click to the next page.

Laser-powered Headlights Availability

Because laser-powered headlights can put out more brightness for their size, the headlamp units themselves can be much smaller.
Because laser-powered headlights can put out more brightness for their size, the headlamp units themselves can be much smaller.
Courtesy of BMW USA

While many of us are still waiting for the day we can afford a car with "mere" LED headlights, there's nothing wrong with drooling just a bit at the thought of flaunting laser beams on our next ride.

BMW, the developer and so far frontrunner on this technology, hasn't yet said when laser-powered headlights will be a regular option on its production cars and SUVs.

But the company has said it plans to turn the i8 Concept into a production vehicle. We'll have to wait and see how many of its innovative features -- including laser beam-powered headlights -- survive to make it to the car that hits the dealerships. And given the "arms-race" nature of the auto business, it's probably a safe bet that other manufacturers are already trying to figure out how to produce their own laser-augmented lighting systems.

For lots more information on laser-powered headlights and other cutting-edge car tech, click to the next page.

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Sources

  • Bmw-i.com. "BMW i8 Concept." (Oct. 16, 2011) http://www.bmw-i.com/en_ww/bmw-i8/
  • Cesa, Dante. "BMW developing laser headlights, officially over LEDs." Engadget.com. Sept. 6, 2011. (Oct. 15, 2011) http://www.engadget.com/2011/09/06/bmw-developing-laser-headlights-officially-over-leds/
  • Dillow, Clay. "Realizing Bondesque Visions, BMW is Mounting Lasers in Its Headlights." Popular Science (popsci.com) Sept. 6, 2011. (Oct. 19, 2011) http://www.popsci.com/cars/article/2011-09/realizing-bond-visions-bmw-mounting-lasers-its-headlights
  • Evans, Scott. "BMW's Laser Headlights – BMW Shows Us How its Freakin' Laser Light Show Works." Motor Trend. Oct. 14, 2011. (Oct. 19, 2011) http://wot.motortrend.com/bmw-shows-us-how-its-laser-headlights-and-dynamic-lightspot-work-126103.html
  • Leavitt, Lydia. "Audi announces A2 electric concept car, uses lasers to ensure safety of future humans." Engadget.com. Sept. 2, 2011. (Oct. 15, 2011) http://www.engadget.com/2011/09/02/audi-announces-a2-electric-concept-car-uses-lasers-to-ensure-sa/
  • Nishimoto, Alex. "Bright Idea? BMW Develops Laser Headlights for i8 Concept, Future Models." Motor Trend. Sept. 2, 2011. (Oct. 18, 2011) http://wot.motortrend.com/bright-idea-bmw-develops-laser-headlights-for-i8-concept-future-models-114051.html
  • Woodyard, Chris. "BMW tests '1,000 times brighter' laser headlights." USA Today. Sept. 5, 2011. (Oct. 20, 2011) http://content.usatoday.com/communities/driveon/post/2011/09/bmw-tests-laser-headlights----1000-times-brighter/1