Lasers have been around since the 1960s but they were just used for scientific research at first. The word “laser” is a tongue-twisting acronym standing for “Light Amplification by Stimulated Emission of Radiation.” Today, lasers are being used for thousands of consumer and commercial applications but none were automotive related. That is about to change.
Laser technology covers a huge gamut. There are massive lasers generated in vacuum containers that are so powerful that they can burn through metal plates. Many of these are built for the military. For consumer purposes, however, most lasers are tiny, chip-based devices that are used in applications as mundane as CD/ DVD players, laser printers and barcode readers. Are you familiar with “blue ray discs”? The term “blue ray” refers to a laser diode that emits light in the blue section of the visible light spectrum.
As we hinted at earlier, laser technology is about to make its debut in the automotive industry. Care to guess where they will be used on cars and trucks? If you guessed “headlights,” then you are right. Lasers are being developed to take the place of conventional headlights. However, they are being used in a way that you may not expect: they are not going to be used to illuminate the road in front of a vehicle, at least not directly. The chip-based technology being used to replace incandescent headlights today is Light Emitting Diode (LED). LEDs are starting to show up on today’s cars and they are throw a very powerful beam of light. A major advantage LED technology has is that they are very small and can be packed into small spaces unlike the old style headlights with huge reflectors. Automotive designers just love LEDs because they can design them into just about any shape they can imagine. The same will be true of laser headlights when they appear on production automobiles.
How they work
Laser light is emitted from chip-based technology just as it is from LEDs. However, the light that comes from laser diodes is more than 1,000 times as powerful than similar size LEDs. The folks at Hyundai of Kennesaw, a local Hyundai dealer in Kennesaw, GA, filled us in on what Hyundai is working on. They are using blue laser diodes to illuminate a white phosphorus target, and the light emitted by this target will be bounced off a reflector and then out the front lens. As it turns out, this is a very efficient way to make powerful light systems.
Why is this better than LEDs?
LED technology is very powerful too and inexpensive but the chips generate a great deal of heat. The current vehicles that are being produced with LED headlamps are using LED chips that have massive heatsinks attached. This is bulky and expensive. The result is that, at least for the near future, LED technology will be used for side indicators and tail lights, not for headlights. The power that needs to be dissipated is simply too great. This is where laser headlights come into play.
As we mentioned, using laser diodes to illuminate a phosphor target is a very efficient way to make light. The result is an intensely bright headlight that stays far cooler than any other light technology. Not only is it an engineer’s dream, It’s also great for car body designers who can now put the headlights in almost any form-factor they desire.