Silica-Based Highly Nonlinear Fibers and Their Application

Silica-based highly nonlinear fibers (HNLFs) have been utilized as platforms for various applications, including fiber lasers, optical amplifiers, and optical signal processings. For the practical applications, nonlinearity enhancement without degrading the attenuation and tailoring the chromatic dispersions remain the key issues. Herein, we initially discuss the design of chromatic dispersions of HNLFs for desired applications. Then the fabrication results, including HNLFs with a longitudinally uniform zero-dispersion wavelength or with optimized higher order dispersion, are presented. Furthermore, using evolved HNLFs, we demonstrate a unique four-wave-mixing-based wavelength conversion. In addition, suppression of the stimulated Brillouin scattering, a critical issue for high-power applications, is discussed. We fabricate Al₂O₃-doped HNLF that has lower Brillouin gain by 6.1 dB as compared with that of conventional GeO ₂-doped HNLF.