Terahertz Devices Based On Photonic Crystals

Terahertz technology has been boosted with the development of its source, detecting technology and application technology in the past twenty years. And it has been proved greatly potential applications in many domains including imaging, environment monitoring, medical diagnosing and broadband mobile communications. And the components and devices in the terahertz range are seriously demanded. The photonic band gap (PBG) structures have been experimentally used effectively in many domains, and can achieve special function by introducing defects in it. These performances do well in the terahertz ranges also. And an important reason for design the terahetz photonic crystal devices is the availability of precision manufacturing techniques in sub-millimeter, as the fabrication of a PBG crystal for the optical region can be a high technical challenge and the size of PBG crystal in microwave is too bulk. Therefore, analysing the photonic crystal material and design the terehertz photonic crystal are significative in applying the THz technology.This paper was to design the photonic crystal devices in terahertz. First, the basic photonic crystal structures were designed including square photonic lattice and triangle photonic lattice, and introducing the different defects to form terahertz broad band filter, super-narrow band filter, cavity and waveguide and so on. Second, the nonlinear dielectric material was introduced into the basic photonic crystal structure to form the effective switch with the kerr nonlinear effect. And the chirped and apodized photonic crystal were constructed by combining with the theory of optical grating. At last, an experiment setup of THz-TDS was established to verify the performances of these terahertz photonic crystal components and devices.