Generate THz Of The Nonlinear Optical And Set Up Imaging Is Studied

The terahertz region of the electromagnetic spectrum covers the frequency range from 0.1 to 10 THz, which is between the infrared and the microwave regimes. This region has not been exploited fully to date owing to the limited number of the suitable radiation sources and detectors. Now, people begin to study the THz gap, but the generation of terahertz waves is one of the key technologies in this study field. The nonlinear optical difference and sum frequency methods is one of the main methods to generate all methods, no threshold, low cost, etc, this is the priority. Thus, in this paper, the theoretical research of THz wave generation using DF and SF is discussed. The main content and innovation pointes in the dissertation are as follows:1.The features of terahertz radiation and the development of the terahertz wave technology are reviewed. The application prospect is introduced. A detailed summary of development and application for the terahertz sources, particularly for the terahertz sources based on the difference frequency method.2.The THz spin wave function has been given.3.The conversion efficiency of the photon not beyond 33.33% for DF and it is not beyond 66.67% for SF has been given, which provides an experimental basis. And the three laws of photon absorbing have been given.4.The model of terahertz wave emitted by the difference frequency generation in DAST is introduced and necessary analysis based on the model is made too.5.The THz delayed imaging is studied.