Laser-powered Headlights: Basic Operation
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.