Double Cladding Seven-Core Photonic Crystal Fibers With Different GVD Properties and Fundamental Supermode Output

We fabricated three kinds of double cladding nonlinear seven-core photonic crystal fibers (PCFs) with different group velocity dispersion (GVD) properties and fundamental supermode output. Pumped by a 150 ps polarization maintaining a ytterbium-doped fiber laser based on the gain-switched technique, octave-spanning supercontinua were generated within the wavelengths from 450 to at least 2000 nm in these fibers with a high spatial quality.