Of Lanthanum Ions And Methylene Blue Doped Kdp Crystal Growth And Crystal Quality

KDP (KH2PO4) crystal is a kind of non-linear optical material with excellent character. KDP crystal is the only nonlinear crystal currently used for laser inertial confinement fusion due to their exclusive physical properties. Considering the electro-optical properties and large diameter, high quality KDP crystal is one of the primary optical crystals used in high-power laser systems. Therefore, growth of large diameter and high quality KDP crystal by changing growth parameters and choosing proper additives has been the researching focus at home and abroad all the while.In this paper, the structure, property and applications of KDP crystal were introduced. The research history and actuality about inorganic anions, metal cation and organic additive were expounded in detail. The influence mechanism of additives on KDP crystal was summarized and explored.KDP crystals were grown by the method of temperature reduction. Growth experiments were carried out by changing the saturation temperatures and pH values of KDP growth solutions. The optimal saturation temperature and pH value were explored. On this basis, KDP growth experiments were carried out by adding lanthanon ions (La3+) and organic dyes (methylene blue) to growth solutions.By comparing the pure with La3+ doped KDP crystals, results shows that the doped of La3+ improves the stability of the KDP growth solution, and reduces defects of KDP crystal. The transmittance of the prismatic section of samples was measured by UV-VIS Spectrophotometer in ranges of 200-800nm, researches found that La3+ with low doped concentration (La3+=4×10-3mol/L) can improve the transmittance of crystals in the UV band, and improve the quality of crystals.As to the KDP crystal doped with methylene blue, when the concentration is high, the stability of the KDP growth solution is declined in the growth process of KDP; We measured the content of impurities in KDP crystals, and found that the total content of trivalent metal ions decreased with the increase of doping concentration. It indicates that doped with methylene blue can effectively inhabit the adsorption of Fe3+, Cr3+, Al3+ in the prismatic section of KDP crystal and weaken the influence of the impurity ions to the prismatic section; The doped crystal structure was characterized by XRD, the results show that different concentrations of methylene blue does not lead to the change of KDP crystal phase, only the crystal Bragg angle and the diffraction intensity have a slight drift.