Torque on birefringence in one-dimensional finite photonic band-gap structure with defects

We theoretically study the optical torque on the layers in one-dimensional finite photonic crystal with birefringent defect layers. The fields in each layer are deduced by Berreman's 4 × 4-matrix method. We found out that the strong electromagnetic fields enhance both torque and force on the layers at defect mode. These investigations suggest an efficient method to construct the micro-motor driven by electromagnetic wave.