Ultrahigh Birefringent Nonlinear Slot Silicon Microfiber With Low Dispersion

A new simple structure of ultrahigh birefringent and ultrahigh nonlinear slot silicon microfiber with highly efficient dispersion reduction is proposed and numerically simulated using the full-vector finite-element method with anisotropic perfectly matched layers. Benefiting from the slot effect-induced sub-wavelength mode confinement, ultrahigh birefringence up to the order of 10^-1 can be realized within a wide wavelength range from 1.4 to 1.7 μm, which is comparable with the results in these ultrahigh birefringent photonic crystal fibers, but cannot be achieved in traditional microfibers. Meanwhile, the nonlinear coefficients of quasi-TE mode and quasi-TM mode at the wavelength of 1.55 μm are as high as 969.58 W^-1m^-1 and 156.74 W^-1m^-1, respectively. Furthermore, the dispersion value of quasi-TE mode at 1.55 μm can be decreased from 1.2358×10³ ps/(nm · km) to 0 ps/(nm· km) simply by modifying the slot size. Owing to its excellent performance, the proposed slot silicon microfiber will have great potential for polarization maintaining nonlinear signal processing applications.