Abstract
This paper reviews recent progress in Photonic Crystal Fiber (PCF) with flattened dispersion characteristics. We describe the chromatic dispersion controllability in various PCFs taking both uniform and non-uniform air hole structures into consideration. We also review recent reports on a highly nonlinear medium that utilizes the dispersion-flattened PCF. Moreover, we introduce the characteristics of a novel dispersion-flattened PCF, which has the potential to become a transmission medium for wideband and high-bit-rate optical communication. We show numerically that the proposed double air cladding structure successfully achieves flat medial dispersion characteristics as well as an enlarged effective area and low confinement loss. Finally, we point out that full controllability of the chromatic dispersion, effective area and confinement loss, along with the fabrication technique, will be key issues to make further progress with the dispersion-flattened PCF.
