Bow-tie holes-aided elliptical-core polarization-maintaining fiber with high birefringence

• A Bow-tie PMF introducing three circular inner-holes of cladding material inside an elliptical-core realizes a high-birefringence performance based on stress and geometric birefringence. • The modal effective area is evaluated over wavelengths ranging from 1250 nm to 2050 nm and demonstrated to be ideal for optical fiber sensors. • The mode performance of this fiber shows a low sensitivity when fluctuations in structural parameters vary up to ±5 % considering the practical fabrication. • The fabrication method is described to demonstrate the feasibility of the fiber design. • This PMF may have potential applications for improving the accuracy of optical fiber sensors. We present a Bow-tie holes-aided elliptical - core polarization-maintaining fiber (PMF) comprised of an outer elliptical-core, with three circular holes of silica material inside it, and two symmetrical Bow-tie stress-applying parts (SAPs), creating a fiber with a superior polarization-maintaining ability by superimposing geometric birefringence on the stress birefringence. The overall modal birefringence of this exceptional fiber design is capable of as high as 8.54 × 10 -4 at a wavelength of 1.55 µm, corresponding to an almost onefold increase compared to a conventional Panda-type PMF. The other significant attribute of the PMF, effective mode area, is also evaluated comprehensively over wavelengths ranging from 1.25 µm to 2.05 µm. Furthermore, we also discuss the sensitivity of the modal properties to fluctuations in the structural parameters of the fiber during the fabrication process to demonstrate that the design has excellent tolerance to deviations in practical fabrication. In summary, the PMF with fine modal properties proposed in this study is a promising candidate for widespread use in high-precision fiber-optic sensors and fiber communication systems.