Symmetric Conjoined Tube Negative Curvature Fiber Based Efficient Polarization Beam Splitter

In this manuscript, we introduce a new negative curvature design based polarization beam splitter device. Two symmetric conjoined tubes are introduced to accomplish the dual core fiber. The finite element solver method was occupied to investigate the attributes of the designed splitter. Depending on computational outcomes, the reported dual core negative curvature based splitter offers outstanding splitting performance in conjoined tube cladding arrangements that cover two popular communication spectra centered at $1.31 \mu \mathrm{~m}$ and $1.55 \mu \mathrm{~m}$. It reveals a short splitter size of 2.84 cm with an ultra-broad band of 420 nm while exceeding a ratio of extinction of 20 dB that covers almost all telecom bands. It achieves a maximal extinction ratio of 152 dB for wavelengths of $1.55 \mu \mathrm{~m}$. Furthermore, the extinction ratio of higher order mode exceeds 100 in spectrum between $1.30 \mu \mathrm{~m}$ to $1.60 \mu \mathrm{~m}$, indicating extreme single-mode features. The proposed negative curvature based splitter is anticipated to be extremely beneficial in optical network technologies.