Speckle Suppression with an Integrated Optical Phased Array and a Multimode Fiber

<jats:p>Coherent light makes optical systems bright and precise, but it can also produce speckle that can degrade imaging, projection, inspection, and metrology. We demonstrate a compact, non-mechanical speckle suppressor in which a 16-channel indium phosphide optical phased array is directly coupled to a 1 m multimode fiber. Electronic phase patterns generate different fiber speckle realizations, whose average follows the predicted OPA-MMF contrast scaling in the quasi-monochromatic single-polarization regime. With polarization diversity and sources filtered to an approximately 2 nm optical bandwidth, the local contrast reaches C=0.035. A square-root emitter layout also improves the coarse illumination envelope, showing that speckle suppression and coarse-illumination homogeneity can be designed together.</jats:p>