Abstract
Lasers appear to be ideal light sources for a variety of projection and imaging systems because of their spectral brightness and their ability to produce a beam of light that can be tightly collimated to travel long distances. Lasers owe these extraordinary properties to a quality called coherence. Yet, lasers are not widely used in imaging and projection applications, because the coherence of laser light is just too extreme. Spatiotemporal coherence of the imaging source leads to artifacts such as speckle, caused by the uncontrolled scattering of laser light and multipath interference that degrade the image considerably. Redding et al. (1) now report how a semiconductor laser based on a chaotic cavity can offer a “compact” solution to this problem. The availability of such low-cost, on-chip semiconductor lasers and the possibility to electrically modulate them make such lasers attractive light sources for a variety of applications, ranging from compact projectors to optical coherence tomography.
