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 2 pi phase shift is achieved at 9V(rms) and 8.1 pi at 40V(rms) using a 12-mu m-thick E7 LC layers. This operating voltage is similar to 10X lower than that using a conventional 0.3-mm-thick glass separator
