An asymmetric dual-core single-polarization single-mode photonic crystal fiber coupler

摘要

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