The Investigation To The Method Of Quasi-Phase-Matching Technology Realization

This work is supported by the national Nature Science Foundation of China. Based on the fundamental principle of nonlinear optics, the principle and condition of quasi-phase matching (QPM) are deeply studied in this thesis. Not only are the traditional QPM theory and approaches analyzed, but also some new ideas and their promising applications are researched in details. The electrical field vector superposition method is used in most of the theoretical models and some errors analysis. Some related experiments are made based on the theoretical results to test the feasibility. The results and points of innovation are as follows, With respect to the theoretical work:1. Optical parameter generation (OPG) spectrum distribution of quasi-phase matching is obtained by further investigating the three-wave interaction equations. Properties of broadband OPG amplifier are also analyzed. (Chapter 2)2. Combining the characteristic curve of electric field of QPM, the influence of all kinds of errors on conversion efficiency is qualitatively and quantitatively analyzed by using electrical field vector superposition method. (Chapter 3)3. Relationship between periodic error and conversion efficiency under non-d33 are especially investigated through vector superposition method. Then principle and method to realizing multi-wavelength frequency conversion under QPM are proposed (Chapter 4).4. The properties of the bi-stable ferroelectric liquid crystal are researched and the possibility of obtaining QPM condition by this material is discussed. Together with the self-established period-embedded structure to minimize the related errors, a liquid crystal QPM component is proposed to get continuous frequency conversion. (Chapter 7)5. The polarization characteristic of the total reflection light is used to meet the QPM condition; a thin crystal layer could act as a QPM frequency conversion component. The idea is certified theoretically. (Chapter 8)With respect to experimental work:1. A high-voltage pulse power is designed and developed for the fabrication of PPKTP crystal (Chapter 5);2. By using of real-time monitoring system, the change inside the KTP crystal domains is detected while the poling of KTP crystals.3. The Second harmonic generation of the self-fabricated PPKTP crystal is experimented and higher efficiency is obtained.4. Utilizing double pulses in KTP crystal poling process for the first time, the domains penetrating is greatly improved.5. A bulk of LiNbO3 crystal is fabricated to realize the total inner reflective QPM performance and its SHG experiments are tried.