Enhanced Visible Light Generation from 1µm Femtosecond Pulses within High-Δ Photonic Crystal Fibers

We demonstrate the blue light generated in high-Δ photonic crystal fibers (PCFs). A femtosecond Yb−doped fiber laser, operating at 1039 nm, is used to pump a GeO₂-doped PCF in the largely anomalous group velocity dispersion (GVD) region. The emitted radiation covers 418.6–544.6 nm with 5 dB flatness. The calculated result indicates that the cross phase module (XPM) effect induced by higher-mode soliton makes a contribution to the blue component generation.