We experimentally demonstrated the manipulation of 2 μm linearly polarized states in a diode-pumped YAG/Tm:YAG/YAG laser with high polarization extinction ratio of 28 dB for the very first time to the best of our knowledge. A stable linearly polarized state of 2 μm was achieved without using any specific intracavity optical polarization-selected elements. The unexpected phenomenon of tunable linear polarization directions was observed. Multidistinct linear polarization directions were experimentally obtained, including the peculiar case of switchable orthogonally linear polarization directions.