Objective Highenergy and highpeakpower 2 μm solidstate laser plays an important role in many fields. Currently, two types of pumping source can be used to pump an Ho∶ YLF laser. One is the Tm doped solidstate laser, and the other is the Tm dopedfiber laser. It is known that Ho∶YLF crystal has different polarized absorption characteristics in the π and σ directions. Therefore, quantitative research on the opticaloptical conversion efficiencies affected by the polarization of the pump light will be remarkably