Microstructure core photonic crystal fiber for blue extension of supercontinuum generation

We investigate photonic crystal fibers (PCFs) with nanosize airholes (NAHs) in the core for the blue extension of supercontinuum generation. The principle behind the design is to enhance the evanescent wave in the IR part of the supercontinuum. When the zero-dispersion wavelength is fixed around 1 μm, the infrared wavelength of 2500 nm of the proposed fiber is able to group-velocity match to the short-wavelength of 403 nm, which is about 60 nm shorter than that of a conventional high-Δ PCF. Simultaneously, the nonlinearity is enhanced about three times. The dependence of PCF characteristics on NAHs is also discussed. Simulated results confirm the possibility of increasing the blueshift of the generated supercontinua in designed PCFs.