A polarization-independent blue phase liquid crystal on silicon with low operation voltage

A polarization-independent blue phase liquid crystal on silicon (BPLCoS) device with low operation voltage for 2π phase depth is demonstrated. With optimized reflection structure and two reflection films, the incident light may experience multifold optical path and 2π phase depth can be obtained. For the polarization-independence, an inclined electric field made by periodical gradient voltage is applied on the blue phase liquid crystal (BPLC) to match the light propagation direction. With the structure, the operation voltage can be lowered to 5.5 V in simulation and 5.9 V in experiment for 2π phase modulation at 1550 nm. The proposed device shows great potential for communication and imaging systems.