In this article, a polarizer based on surface plasmon resonance in a squeezed rectangular lattice is analyzed through a full-vector finite-element method solver. The device allows one state of polarization (e.g., y-polarized mode) to propagate through the fiber while the other state (x-polarized mode) is heavily attenuated: the modal losses for the x- and y-polarized modes are 1221 dB/cm and 1.6 dB/cm, respectively, at the wavelength of 1310 nm. Given the high differential attenuation between the two orthogonal polarization modes, the device could be used as a compact polarizer with potential applications in sensing, communications, and other areas.