Effective D-shape fiber with air hole assistant design for birefringence analysis

We propose an elliptic core effective D-shaped fiber with air hole assistant for birefringence applications. The proposed birefringent fiber works on the principle of asymmetric core region. The birefringence of the proposed D-shaped fiber has been numerically investigated in detail. The designed fiber has effective mode areas of 16.04 μm2 and 16.06 μm2 for x-and y-polarization modes, respectively, at a wavelength of 1550 nm. Our numerical results reveal a birefringence and confinement loss of 2.25 × 10−4 and 6.66 × 10−3 dB/m respectively at 1550 nm wavelength. The proposed fiber exhibits a dispersion variation of 1.3 ps/km-nm and 1.57 ps/km-nm respectively for x-and y-polarizations over a wavelength band of 200 nm ranging from 1.4 to 1.6 μm. We have also investigated the influence of variation in the fiber parameters on the birefringence and dispersion. Furthermore, we have calculated the fabrication tolerances, the variation of birefringence value is very small by varying the air hole diameters of the fiber. We believe that the reported results have potential importance in the design and development of polarization control devices applicable in fiber-optic sensors.