Temperature modulation of the superprism effect in photonic crystals composed of the copper oxide high-temperature superconductor

We have designed a two-dimensional triangular photonic crystal using a copper oxide high-temperature superconductor that can control the superprism effect. The refractive direction of light in the photonic crystal is determined by calculating the direction of the group velocity of the light in the photonic crystal. By tuning the temperature of the superconductor, the photonic band structure as well as the equifrequency surface is changed. When the incident angle is fixed, the refractive angle can be changed by varying the temperature. We choose an operation frequency of omega = 0.83(2 pi c/a) and a fixed incident angle of theta = 13 degrees for discussion. The refractive angle of light in the photonic crystal changes about 28 degrees when the temperature is increased from T = 5 to 101) K. All the equifrequency surfaces of the photonic crystal are calculated by the plane-wave expansion method. and simulations on the propagation of light are investigated by the finite-difference time-domain method.