Most people believe that exposure to laser light can damage the retina, and if a driver is hit by laser headlights from an oncoming car, the consequences could be unimaginable. However, this is a common misunderstanding. The key point is that lasers in automotive headlights are not direct light sources but rather excitation sources used to generate white light.
For example, the BMW i8's laser headlight system consists of four main components: a laser source, a mirror, a yellow phosphor filter, and a reflective bowl. A blue laser diode emits light, which is reflected by the mirror and focused onto the yellow phosphor filter. The phosphor absorbs the blue laser energy and converts it into white light, which is then reflected again by the reflective bowl to create a concentrated beam of illumination. Therefore, even though the system uses blue lasers, the resulting light is not a true laser—it’s white light generated through this process.
Although the principle of laser headlights is similar to that of LED headlights, there are significant differences. Laser headlights produce 1.7 times more light intensity than LEDs with the same power, and they are also smaller in size. This makes them ideal for high-performance applications.
However, laser headlights come with their own challenges. One major limitation is that lasers are point sources, meaning they emit light in a narrow, focused beam. While this provides excellent range, it makes it difficult to spread the light over a wide area—similar to how a laser rangefinder works. This poses a technical challenge when trying to illuminate a large surface effectively.
Another issue is cost. Laser headlights are currently only available in high-end luxury vehicles, making them inaccessible for most consumers. In the aftermarket, modifying a vehicle to use laser headlights is a complex and expensive process. Unlike LED headlights, which can be easily upgraded without damaging the original system, laser headlights require the installation of both a laser module and an LED module, adding to the complexity and cost.
Additionally, safety features are crucial. In high-end models like BMW, laser headlights are designed to activate only at speeds above 40 km/h and automatically turn off in case of collision or extreme conditions. Some systems even include smart lighting technology to prevent glare for oncoming drivers.
In summary, laser headlights represent the next evolution in automotive lighting, offering improved brightness and efficiency compared to traditional LEDs. However, due to their point-source nature and high cost, they are more likely to complement intelligent LED systems rather than replace them entirely. As technology advances, we may see laser headlights become more accessible and integrated into mainstream automotive design.
Jiangmen Hongli Energy Co.ltd , https://www.honglienergy.com