The Research On Quasi-Phase-Matched Optical Parametric Generation Based On Periodically Poled Crystal

Optical parametric generation (OPG) is an important method to obtain the infrared coherent light source. It is compact and convenient to be seeded. The OPG based on quasi-phase-matching (QPM) technology is the focus in the nonlinear optical area. The periodically poled crystal used in QPM can compensate the phase mismatch in the three-wave interaction by reversing the electric susceptibility periodically. This crystal is an ideal nonlinear crystal, which can apply the maximum nonlinear coefficient, avoid the walk-off effect and apply the whole transmission range of the crystal. This dissertation discusses on several experiments about QPM-OPG, supported by"National Natural Science Foundation of China","the Science & Technology Cooperation Foundation of Nankai University and Tianjin University, the Ministry of Education","the Ph.D. Programs Foundation of Ministry of Education of China"and"Tianjin municipal technological development planning". The main content is described as followed:1. The directions of three wave vectors in QPM-OPG are theoretically analyzed for the first time. The calculation shows that the direction of signal light is along the direction of pump light, but the idler light has a little walk-off angle to the pump light. The result is demonstrated by the experiment, and we find that the approximation of"effective grating"is a reasonable method to analyze the QPM-OPG;2. A new tuning method of QPM-OPG, wedge-angle tuning method, is developed in experiment. A congruent LiNbO3 with different wedge angle is used to change the direction of the pump light, and then to tune the output wavelength of OPG. The signal tuning range over 10nm is obtained by varying the wedge angle from 0°to 10°. The average output signal power is over 70mW;3. A QPM-OPG seeded by tunable diode laser (TDL) is demonstrated in experiment. The output signal power is 288mW, and the corresponding idler power is 134mW. We observed that the line width became narrow after the TDL seeding.4. For the first time, the dual-signal-wave (DSW) QPM-OPG based on two periodically poled crystals is demonstrated. Dual signal wavelength of...