The role of artificial defects for engineering large effective mode area, flat chromatic dispersion, and low leakage losses in photonic crystal fibers: Towards high speed reconfigurable transmission platforms

摘要

The present paper describes a novel systematic solution to thechallenging task of realizing photonic crystal fibers (PCFs) with flatchromatic dispersion, low leakage losses, and large mode area, mainly forapplications as information carriers in wide-band high speed opticaltransmission systems. The proposed design strategy is based on theexistence of an artificially-defected air-hole ring in the cladding and on themodulation of the refractive index of the core by assembling additionaldefected air-holes in the central core region of the fiber. The validation ofthe proposed design is carried out by adopting an efficient full-vectorialfinite element method with perfectly matched layers for accuratecharacterization of PCFs. The remarkable flat chromatic dispersion as wellas the large mode area and the low leakage losses are the main advantagesof the proposed PCF structure, making it an ideal candidate for performingwavelength division multiplexing operation in reconfigurable opticaltransmission systems or as an information delivering platform in high speedoptical communication systems. Typical characteristics of the newlyproposed PCF are: flattened chromatic dispersion of 6.3±0.5 ps/km/nm inthe S+C+L telecommunication band, and effective mode area as large as100 μm2 in the same wavelength range. We additionally provide numericaldata about the performance of the proposed PCF in splicing mode as well asduring macrobending operation and we give qualitative informationregarding the sensitivity of the proposed transmission platform to structuraldisorders of the design parameters.