Growth And Properties Of Sm:KTP Crystal&Laser Induced Crystallization In KTP Glass

Potassium titanyl phosphate(KTiOPO4or KTP) is an excellent material with perfect nonlinear optical (NLO) properties. Although the technology about growth of KTP crystal has been extremely complete, there are still many defects in its practical applications. The high conductivity along c direction has limited its applications in electro-optical areas. Scientists have conducted a lot of researches about the factors that influence the conductivity of KTP crystal.Several explanations have been put forward to interpreter the reason why the conductivity of the KTP crystal is so high when it is grown by high temperature solution method. Scientists have proposed doping as an effective method to deal with this problem. However, the works done in the field of rare earth doping are scarce. Further researches should be conducted to investigate whether it is helpful for the reducing of the conductivity KTP crystal when rare earth elements are doped in. What’s more, scientists are also trying to discover the doping influences on other properties of KTP crystal. In addition to this conductivity defect, the size of KTP crystals grown by conventional ways tend to be fairly large, which greatly limits its microscopic applications in the fabrication of devices. Therefore, scientists have strived to find ways to modify materials which have the similar chemical composition with KTP crystal in micron or nanometer scale, intending to provide the materials with crystal structures and properties. In this way, this material may be widely applied in the microscopic scale. To deal with these two problems, we have conducted following works:1. Doped KTP crystals growth and analysis of the effects doping may bring to KTP crystalsIn this work, we have grown Sm:KTP crystals by slow cooling method in high temperature solution. The conductivity of Sm3+:KTP crystal has been determined in alternating current (AC). Results show that when doped with Sm3+, the conductivity tends to be lower. Other measurements, including the second harmonic generation (SHG) test and UV/Vis/NIR spectroscopy have been employed to characterize the crystal. No significant impact is observed when Sm3+was doped.2. KTP glass preparation and laser-induced crystallizationKTP glasses of perfect properties have been successfully prepared with the growing method of KTP crystal. Near infrared spectroscopy has been employed to character the glasses. KTP glasses are disposed with the process of heat treatment, in which the formation of KTP crystal structure is verified with X-ray powder diffraction (XRPD) and SHG test. The experimental results have also shown promising prospect of laser-induced crystallization in Sm3+:KTP glass.