Linear and nonlinear optical properties of the optical fiber doped with silicon nano-particles

We report for the first time the realization of the optical fiber doped with silicon nano-particles. Silica glass optical fibers incorporated with silicon nano-particles were fabricated by the modified chemical vapor deposition and the solution doping technique. We found that a broadband absorption appeared at 450–1300 nm and a photoluminescence band appeared at 600–1100 nm upon pumping with the Ar-ion laser, indicating that silicon nano-particles were successfully incorporated in the fiber core. We also estimated the third-order optical nonlinearity of the optical fibers by measuring the fringe shift obtained from the long-period gratings upon pumping with the Ar-ion laser from 477 to 512 nm. Importantly the optical nonlinearity at 1550 nm was found to be ∼1.5 × 10−15 m2/W and we believe that this large optical nonlinearity is caused by the exciton absorption of the silicon particles.