We propose a novel kind of polarization splitter in all-solid photonic crystal fibers based on the mode interference effects. Both the full-vector finite-element method and the semi-vector three-dimensional beam propagation method are employed to design and analyze the characteristics of the splitter. Numerical simulations show that x-polarized and y-polarized modes are split entirely along with 6: 8 mm long propagation. An extinction ratio of more than 20 dB and a crosstalk of less than -20 dB are obtained within the wavelength range of 1.541-1.556 mu m. The extinction ratio and the crosstalk at 1.55 mu m are 28.9 and -29.0 dB for x polarization, while the extinction ratio and the crosstalk at 1.55 mu m are 29.9 and -29.8 dB for y polarization, respectively. (C) 2010 Optical Society of America