Ultra-flattened chromatic dispersion control for circular photonic crystal fibers

Abstract

A simple design procedure is utilized for achieving circular photonic crystal fibers withultra-flattened chromatic dispersion. This procedure only requires four parameters (threeair-hole diameters and one concentric spacing). The influence of the diameter of each air-holering on the circular PCF is investigated by simulations. The results show that the influenceof air-hole size of each ring on the dispersion weakens from the inside ring to the outside.Based on the simulation results, an optimization procedure is utilized to control dispersionof the circular PCF. Through the reasonable set of concentric spacing and air-holediameters of the inner three rings, a five-ring circular PCF with a flattened dispersion of0 ± 0.5 ps km − 1 nm − 1 within the wavelength rangeof 1.215–2.02 µm is achieved. Alow confinement loss of 3.2 × 10 − 3 dB km − 1 at 1.55 µm wavelength is simultaneously obtained. The influence of manufacturing imperfections ofparameters on dispersion is also discussed to verify the robustness of our design.