A novel single-polarization single-mode photonic crystal fiber coupler

摘要

A vectorial finite element method is adopted to investigate this novel single-mode single-polarization (SPSM) photonic crystal fiber coupler which has asymmetric dual-core and two lines of enlarged air holes, we demonstrate that the SPSM region of the designed fiber can be more than 250nm wide for a set of optimized air-hole parameters and show that the width of the SPSM region could change slightly by little adjustment of the large inner air holes. The coupling length between the odd and even x-polarization modes are also investigated through fine-tuning the large and small air-hole diameters.