A polarization-independent phase-only liquid crystal (LC) phase modulator using a double-layered structure is demonstrated. Two orthogonal LC layers are separated by two ultra-thin anisotropic polymer films. The anisotropic polymeric films not only separate the LC layers but also provide good molecular alignment. As a result, a polarization-independent phase modulator with 2π phase shift is achieved at 9Vrms and 8.1π at 40Vrms using a 12-μm-thick E7 LC layers. This operating voltage is ∼10X lower than that using a conventional 0.3-mm-thick glass separator.