Multimaterial Fibers

Recent progress in combining multiple materials with disparate optical, electronic, and thermomechanical properties monolithically in the same fiber drawn from a preform is paving the way to a new generation of multimaterial fibers endowed with unique functionalities delivered at optical fiber length scales and costs. A wide range of unique devices have been developed to date in fiber form‐factor using this strategy, such as transversely emitting fiber lasers, fibers that detect light, heat, or sound impinging on their external surfaces, and fibers containing crystalline semiconductor cores. Incorporating such fibers in future fabrics will lead to textiles with sophisticated functionality. Additionally, long‐standing issues in traditional applications of optical fibers have been addressed by multimaterial fibers, such as photonic bandgap guidance in hollow‐core all‐solid‐cladding fibers and imparting mechanical robustness to soft‐glass mid‐infrared fibers. We review recent progress in this nascent but rapidly growing field and highlight areas where growth is anticipated. Furthermore, the insights emerging from this research are pointing to new ways that the fiber drawing process itself may be leveraged as a fabrication methodology. In particular, we describe recent efforts directed at appropriating multimaterial‐fiber drawing for chemical synthesis and the fabrication of nanostructures such as nanowire arrays and structured nanoparticles.