The lasers will be safely contained, with no chance of bouncing their fierce rays off unfortunate retinas, even in the event of a collision. That's because the BMW lamps turn the intense blue beam into a tightly concentrated but nonlaser—and therefore eye-friendly—cone of white light.
The production version will have up to four Class 4 blue-laser diodes. Collimating lenses will direct their beams onto a phosphorus plate that will convert the laser beams to white light, which will bounce off secondary optics and reflect onto the road. To show me how it works, here in the night simulator lab, Erdl dips a phosphorus wafer into a blue laser beam. The wafer blocks some laser photons and lets others stream through. Among the blocked photons, some stimulate—or "pump"—the phosphorus atoms to emit yellow light. The mix of blue light streaming through and yellow emitted from within produces brilliant white light. It's the basic technique used, at lower intensities, in most white-light-emitting LEDs.
