Why BMW i8's Laser Headlamps Are Terrifically Brilliant

Oh Gosh!! It's Diwali! BMW is planning to launch its highly innovative i8 hybrid sportscar in India by next month. We all know about this car, claimed as "car from future", it was even showcased at our Delhi auto expo last year. A slice of this BMW's remarkableness is its Laser headlights, i.e its high-beam with laser light technology, which made i8 the first production car to feature laser tech. This is a step further in the lighting techs used in cars, offering better visibility, efficiency and smaller lamp designs. So how does it work??

Car lighting is an intrinsic part of motoring. We, in India, are still in the era of round, rectangular sealed beams for most of our vehicles. Car customization actually starts with additional lamps isn't it?? We have some dated headlight-brightness regulations, which is hardly followed and sometimes redundant! (What's the use of black strips or black dots on the dooms with multi-reflectors by the way?) There are very few cars that comes with day-time running LED strips, leave alone the full LED headlights or HIDs. We use only halogens prevalently.

But lighting technology has really come a long way. From incandescents to halogens to HIDs to LEDs. Now a step further to Laser technology. In a silly battle over who would bring out first, BMW succeeded Audi in introducing laser tech for a production car, the i8. BMW says its lights are 30 percent more energy-efficient than LEDs and illuminate up to double the distance, about 2000 feet. 

Laser tech is the one used in our CD, DVD or Blu-ray players, or for correcting blurry eye vision and creating dancing dots. etc. But wait a minute, haven't we always been warned that laser could blind us with its intensity? Aren't they so focuses and coherent, tiny beams capable of damaging our retinas? So what are we supposed to do if they are used in cars? A UV spectacle for other drivers?? Lol - we are already annoyed at nights due to unregulated lighting culture, should this also be added?

But that's where we got it wrong. That's not how i8 laser headlamps work. It is actually incorrect to call them as laser headlights, but are merely "laser-powered" ones because direct laser light is not focused towards road. Instead, the system includes a trio of blue-laser diodes located at the back of the light assembly, which is focused to a set of mirrors. These mirrors reverses the ray's direction to pass through a lens filled with yellow phosphorus.

BMW i8: 1. Laser Diodes, 2. Mirrors and Prism, 3. Lens with Yellow Phosphorous (White light), 4. Reflector

Yellow phosphorus is capable of emitting light and when blue laser light passes through it, it emits a brilliant white light. It is then bounced off a reflector, gets diffused and comes out of the doom. The wonder this lighting system does is fantastic. It can be 1000 times brighter than an LED but consumes 2/3rd of power only. Along with increased brightness and photon-density, the beam is glare-free and precise, can help solve "blinding the opposite" issue without compromising visibility. The heat generated is very minimum, even lower than LEDs. The actual light from headlight isn't a coherent laser beam, thus safe to look through open eyes. Laser technology also allows for more compact headlamps for intricate designs - the space constraint under the hood is gone now. That gives i8 a frontal design like never before since history.

BMW i8: Low beam and High beam (Laser)

But the laser light is not as precise as LEDs, and so the i8 still uses latter for low beams. The car can switch on its own from low to high beam and activates the laserlights once it gets to a open road. BMW says that system automatically shuts down in case of any damage to headlamps, preventing raw blue-laser rays to come in contact with people. Overriding this safety setup can be theoretically possible, considering the way hackers progress, but the company should be working further in this regard by now.

The i8, to me, is a car that made me feel that future motoring doesn't have to be really creepy due to electric drive and 'green' concerns. The way i8 headlamp system is efficient is a huge step forward, especially for a hybrid car that tries to optimally use energy is every way possible. Laser powered lights are successful, Audi is also spearheading this transformation and I'm keen to see these on many vehicles in the days to come.

BMW i8 Hybrid has a 1.5L 3-cyl turbo-charged engine with an electric motor.

Also Read: BMW i3 redefines Sustainable Car Technology

Photo Credit: CarAndDriver.com, Popularmechanics.com, Autocarindia.com