The spatial coherence of laser sources has limited their application toparallel imaging and projection due to coherent artifacts, such as speckle. Incontrast, traditional incoherent light sources, such as thermal sources orlight emitting diodes (LEDs), provide relatively low power per independentspatial mode. Here, we present a chip-scale, electrically-pumped semiconductorlaser based on a novel design, demonstrating high power per mode with muchlower spatial coherence than conventional laser sources. The laser resonatorwas fabricated with a chaotic, D-shaped cavity optimized to achieve highlymultimode lasing. Lasing occurs simultaneously and independently in ~1000modes, and hence the total emission exhibits very low spatial coherence.Speckle-free full-field imaging is demonstrated using the chaotic cavity laseras the illumination source. The power per mode of the sample illumination isseveral orders of magnitude higher than that of a LED or thermal light source.Such a compact, low-cost source, which combines the low spatial coherence of aLED with the high spectral radiance of a laser, could enable a wide range ofhigh-speed, full-field imaging and projection applications.
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