The Study Of Reflective Phase Matching Method

Optical frequency conversion is an important branch of nonlinear optics since the laser has been discovered.Phase matching technique is a potential research field.For example,birefringence phase matching,quasi-phase matching,Fabry-Perot cavity-phase matching and Fresnel phase matching have been widely used in Harmonic wave enhancement,laser physics and optical technology.The relative researches on phase matching technology are always hot topics.The thesis first introduces the coupled wave equation of nonlinear optics and common phase matching techniques of nonlinear optics.Then,by extending the principle of phase matching technique,theoretically we propose and introduce the method of reflective phase matching,which bases the FPM and the 1DPCs quasi-phase matching and Fresnel phase matching,experimentally we design a sandwich structure of "high reflective film-nonlinear photonic crystal-high reflective film" to realize our method.The content of the thesis mainly includes the following two aspects:1.In this thesis,the common principle is extended,and a new type of sandwich structure of "high reflective film-nonlinear photonic crystal-high reflective film" made of materials which can provide high reflectivity and nearly odd times of ? reflection phase shift is proposed to promote Fresnel phase matching technology.In theory,through the derivation of the coupling wave equation of nonlinear optics,the light intensity equation of the reflected phase matched output frequency doubled light is obtained,and the second harmonic intensity distribution under different phase compensation is calculated by software simulation.2.Experimentally by using the metal and 1DPC as the reflective medium,the conventional Fresnel phase matching concept can be stretched to RPM.Experimentally the maximum output SHG signal is 52 times higher than the phase mismatch case in a single-domain Mg O:CLN wafer.The advantage of this method can greatly reduce the walk-off effect with outstanding phase compensating ability.Our results can be straightforwardly applied to the realization of miniaturized optical systems based on optical polarization rotation metamaterials.