Optical Switch Theory Research Basing On One-Dimensional Photonic Crystal

In the process of controlling the transmission of the light, the photonic crystal optical switching devices have more advantages than the traditional optical switching devices, and it is the ideal choice for the future integrated optical circuit components. Compared with other forms of optical switching devices, as the new type of optical switching devices, the photonic crystal optical switching devices have the great advantages in many aspects, such as, the great contrast of the transmission when the switching is on and off, controllable of the function range , ultrafast switching time, low energy cost, reliability and so on. In this thesis, the design process of one-dimensional photonic crystal optical switching doped by KTP has been numerically investigated, including:1. The transmission spectrum, forbidden band position, the bandwidth have been analyzed in detail by using transfer matrix method, the analysis details are: the different incident angle, the ratio of high and low refractive index, different center wavelength and periodicity of the one-dimensional photonic crystal.2. The doped one-dimensional photonic crystals are investigated in many aspect, including:In the form of one layer doped one-dimensional photonic crystal, the influence of the defect modes are investigated by changing the optical thickness of the defect layer, the refractive of the defect layer, the position of the defect layer, the periodicity of the one-dimensional photonic crystals on the side of the defect layer and the plural number refractive index. Therein, one-dimensional photonic crystal optical switching can be designed by changing the refractive of the defect layer.In the form of much layers doped one-dimensional photonic crystal, the influence of the defect modes are investigated by changing the position of the defect layers, the number of the defect layers and the distributing of the defect layers. Therein, one-dimensional photonic crystal multiple channeled optical switching can be designed by changing the number of the defect layers and the distributing of the defect layers, this innovation has the potential application in designing the wavelength division multiplexing system.3. A kind of optical switching which based on one-dimensional photonic crystal doped by KTP is investigated. The transmission properties of the structure are studied by transfer-matrix method. For the light with a certain wavelength, the defect mode moves along the direction of long wavelength when the temperature getting higher, numerical investigation shows it can not cut off the light. When the KTP is put on the direct current field, the transmission of the device gets down blow the switch threshold value if the direct current field is above a certain value, and the device become a optical switch. When the KTP is put on the alternating current field, the interval period of pulses is just half the period of external electric field, we can get the pulse of the certain frequency that we want by modulating the frequency of the external electric field. This optical switch will play a potential role in the future of the photonic devices.