CO₂ Laser‐Induced Directional Recrystallization to Produce Single Crystal Silicon‐Core Optical Fibers with Low Loss

Reduced losses in silicon-core fibers are obtained using CO2 laser directional recrystallization of the core. Single crystals with aspect ratios up to 1500:1 are reported, limited by the scan range of the equipment. This processing technique holds promise for bringing crystalline silicon-core fibers to a central role in nonlinear optics and signal processing applications.