Terahertz Photonic Crystal Filter Design

In this dissertation, we are researching into photonic crystals (PCs) mainly from the following aspects: design and error analysis of one-dimensional THz PC multi-channel filter, design and error analysis of polarized THz PC single-channel and multi-channel filters.Firstly, one-dimensional THz tunable PC filter is designed based on simulated annealing algorithm. Because of its good characteristics, THz can be used in nondestructive examination, quality monitoring, biophotonic imaging,and so on. The recent report shows that THz has unique features in communications. Since the filter is one of the common devices in communications, it appears to be very important to design and fabricate the THz filter with THz wave. We design several different aperiodic photonic quantum-well (APQW) structures to achieve the filter function in preassigned wave length range. The result shows that most of the simulation designs can achieve preassigned function. Even for small errors , the function can meet the requirement well.Secondly, we use simulated annealing algorithm to design polarized THz PC for multiple wavelengths. The deduction formulas of transfer matrix method are carried out for different polarizations. When the incident light is off normal incidence, a special PC usually has different forbidden bands for TE and TM polarized waves. Therefore, we need to choose a frequency in the common forbidden band in desiging the PC filter for different polarizations. In this design several different aperiodic photonic quantum-well (APQW) structures are introduced for optimization. In addition, error analysis are implemented.