Turnable Phase Shifter With Zero Refractive Index Photonic Crystal

In this work, a phase shifter composed of cascaded photonic crystals (PCs) was proposed. The PCs with the property of near-zero refractive index at and near Dirac point frequency have zero phase delay. By cascading two identical PCs, an arbitrarily tunable 360° phase-shifter which can be tuned linearly is demonstrated. The properties of such presented PC structure are well described by comprehensive numerical simulations.