Physics and chemistry in Chinese Academy of Sciences xinjiang four yuan alkali infrared nonlinear optical crystal research progress
takeaway: far-infrared laser ( 2 - 20 μm） On defense, communications, medical and security has important applications, including infrared nonlinear optical crystal is the key to the implementation of far infrared laser output device.
in the far infrared laser ( 2 - 20 μm） On defense, communications, medical and security has important applications, including infrared nonlinear optical crystal is the key to the implementation of far infrared laser output device. The current commercial infrared nonlinear optical crystal defects various performance, limit the scope of their application. Therefore, design and exploring new infrared nonlinear material become the important direction of infrared laser field.
technical institute of physics and chemistry of the Chinese Academy of Sciences, xinjiang photoelectric functional material team since 2013 for the research of infrared nonlinear optical material gradually, through the research found in Hg cation and the coordination of environment, and when its tetrahedron primitives with easy distortion and alkali metal when combined to form the center symmetric structure. So the researchers choose Na - Hg- M - S（ M = Si, Ge, Sn） System as the research object, through in an airtight vacuum quartz tube in high temperature solid phase reaction, end up with three kinds of excellent properties of four alkali metal infrared nonlinear optical materials, namely Na2Hg3Si2S8, Na2Hg3Ge2S8, Na2Hg3Sn2S8. Crystallization of the three material in the center of the same non symmetric space group, P c2, observing its crystal structure, found a special channel structure, including closed, half-open, and open channel.
in addition, with other alkali isomorphism ( Na- Cs) Structure comparison, the researchers also found that these compounds are crystallization in the different space group, and the structure symmetry with the alkali metal ion radius decreased gradually increase, the change rule in four yuan metal sulfur is rarely found in the compound. Found performance tests show that the three kinds of materials have good optical performance, basic meet the requirements of the excellent infrared nonlinear optical materials, including the wide through the scope, high laser damage threshold, large nonlinear coefficient and stability of the environment. Which Na2Hg3Si2S8 and Na2Hg3Ge2S8 well realize the high laser damage threshold and the balance between large nonlinear coefficient, elimination of the current commercial infrared nonlinear optical crystals, a series of performance defects ( Low laser damage threshold and strong two-photon absorption) , can be used as a potential excellent infrared nonlinear optical material. The introduction of alkali metal and d10 element control crystal structure to design a new type infrared nonlinear material provides an effective way of thinking.
the results of the study was published in the near future in the Chemistry of Materials.
related research work are the light of 'western' project of Chinese Academy of Sciences, national natural science fund project funding.
Na2Hg3M2S8 ( M = Si、通用电气和Sn) Crystal structure and the performance index