Terahertz Photonic Crystal Functional Devices

Terahertz (THz) frequencies refer to the electromagnetic wave which frequency within in the region from 0.1THz to 10THz (wavelength region from 3000μm to 30μm), terahertz science and technology is a very complex frontier discipline. In the past 20 years, the terahertz science and technology has made a great development with the progress of THz generation mechanism, detection technology and application technology.The application of THz technology can not be separated from the development of THz radiation sources and THz detection technology; it also needs the development of THz devices. As a new optical and electromagnetic material, Photonic Crystal has photonic band gap structure, and was composed of dielectric material which refractive index changed periodically. It can be introduced defect and changed its structure reasonably according to the specific necessaries, it's also adjustable. The Photonic Crystal structure can also be applied in the THz region, this application is one of the popular research fields in terahertz technology.In this dissertation, Photonic Crystal's band gap characteristics and theoretical calculation methods were researched firstly. By using these methods, kinds of Photonic Crystal devices in THz region are designed, they are mainly 2-D Photonic Crystal waveguides and Photonic Crystal filters, Photonic Crystal waveguides mainly include straight waveguides at 100GHz and 225GHz, bended waveguide and Y-branch waveguide; Photonic Crystal filters mainly include band-stop filter, super narrow band filter and frequency-selected filter. All these devices designed have been simulated and optimized by the electromagnetic simulation tools based on the FDTD theory, so that the devices could achieve optimal quality of transmission or filtering. Research results are potential valuable for the development of Photonic Crystal devices in THz region.