Abstract:We demonstrate a switchable two-dimensional phase grating in blue phase liquid crystal (BPLC), which is fabricated by sawtooth in-plane-switch (IPS) electrodes. They are used to generate the horizontal electric field on a single indium-tin-oxide (ITO) glass substrate and, as a result, the 1-D and 2-D phase gratings can be mutual switched via different polarizations of incident light with an applied voltage. The first-order diffraction efficiency is up to 20% and 10% for the 1-D and 2-D phase grating at V = 150 V, respectively. Moreover, the rise and decay time is 0.9 and 1.1 ms, respectively, which is suitable for wide applications of high-speed optical manipulations.