In this paper, the rigorous coupled-wave analysis theory is used to simulate a hybrid Si/SiO₂ high-contrast grating using a liquid crystal as a low refractive index material, which is suitable for liquid crystal tunable vertical-cavity surface-emitting lasers (VCSEL). Using 940-nm TM polarized incident light, the parameters of the grating structure can be optimized to obtain broadband (Δλ=256 nm), high reflectivity (R>99%), and polarization-stabilized characteristics that satisfy the VCSEL top mirror requirements. Changes in the refractive index of the liquid crystal do not affect the quality of the grating. Liquid crystal tunable VCSELs are expected to be combined with different high-contrast gratings and hybrid gratings in the future.