Field-induced 1D/2D switchable grating based on a polymer-dispersed liquid crystal.

This letter proposes a 1D/2D switchable grating that is fabricated by injecting a mixture of polymer and liquid crystal (LC) into a LC cell with in-plane switching (IPS) electrodes and using a photomask for polymer-induced phase separation. The switching between 1D and 2D gratings is achieved through an external electric field. In the absence of an external electric field, a 1D polymer dispersed LC (PDLC) grating is presented; under the presence of an external electric field, the PDLC grating couples with the IPS electrode to form a 2D grating. It features a low driving voltage, low saturation voltage, and fast response. It is worth noting that since the 1D/2D switchable grating is composed of two independent gratings coupled together, it is not limited by the period and angle of conventional 2D gratings. The period size and fringe direction of the two gratings can be adjusted by replacing the IPS electrode or PDLC grating, thereby forming diverse diffraction patterns, which has great potential in photonics applications.