Material properties of tapered crystalline silicon core fibers

Crystalline silicon optical fibers are emerging as a promising platform for a wide range of optoelectronic applications. Here we report a crystallographic study of the material properties within silicon fibers that have been post-processed via a tapering procedure to obtain small, few micron-sized core diameters. Our results reveal that the tapering process can improve the polysilicon quality of the core through the formation of large, centimeter long crystal grains, thus significantly reducing the optical losses.