Dispersion Optimization in GeO۲-doped Silica Photonic Crystal Fibers with Circular Lattice

In this paper, we analyze the dispersion properties of photonic crystal fiber with the core replaced by a composite of ۸۵% SiO۲-۱۵% GeO۲. The air hole's radii of the layers in the cladding are designed differently to improve the dispersion and nonlinear properties of the fibers. Both anomalous and all-normal dispersions have been optimized. Based on numerical simulation results, two optimal structures (d۱/Ʌ = ۰.۴, Ʌ = ۰.۹ µm and d۱/Ʌ = ۰.۴۵ and Ʌ = ۱.۰ µm) are proposed with a very small dispersion value of ۰.۲۹۸ ps/ nm.km and −۰.۳۱۱ ps/nm.km at the pump wavelength of ۱.۵۳ µm and ۰.۹۸۵ µm, respectively. The high nonlinear coefficient, small effective mode area, and very low attenuation of about ۱۰−۷ dB/m at the pump wavelength are also favorable conditions for the application of broad-spectrum supercontinuum with low peak power. The proposed fibers can be new supercontinuum sources that effectively replace glass core fibers.

Keywords:

photonic crystal fibers , composite SiO۲-GeO۲ , flat dispersion , small effective mode area , low attenuation