Notable third-order optical nonlinearities of a Keplerate-type polyoxometalate in solution and in thin films of PMMA

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• 作者：Yunshan Zhou (1) (2)
  Zonghai Shi (1)
  Lijuan Zhang (1)
  Sadaf ul Hassan (1)
  Ningning Qu (1)
  
• 刊名：Applied Physics A: Materials Science & Processing
• 出版年：2013
• 出版时间：November 2013
• 年：2013
• 卷：113
• 期：3
• 页码：563-568
• 全文大小：
• 作者单位：Yunshan Zhou (1) (2)
  Zonghai Shi (1)
  Lijuan Zhang (1)
  Sadaf ul Hassan (1)
  Ningning Qu (1)
  
  1. State Key Laboratory of Chemical Resource Engineering, Institute of Science, Beijing University of Chemical Technology, Beijing, 100029, P.R. China
  2. Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P.R. China
  
• ISSN：1432-0630

文摘

The third-order nonlinear optical properties of a Keplerate-type polyoxometalate (NH4)18[(Bu4N]24[Mo132O372(H2O)72(CH3COO)30]ca.7NH4CH3COOca.173H2O (denoted Bu4N-{Mo132}) in solution and in films of poly(methylmethacrylate) (denoted PMMA) matrix have been studied by the Z-scan method at 532 nm with a pulse duration of 20 ps. Experimental results show that both the solution and the solid films of Bu4N-{Mo132} have nonlinear self-defocusing effects and notable nonlinear reverse saturable absorption. Embedding Bu4N-{Mo132} as inclusion into PMMA host significantly improves the nonlinear absorption coefficient while it reduces the nonlinear refractive coefficient as a result of the higher concentration of Bu4N-{Mo132} in PMMA matrix than in solution. The magnitude of for solid-state Bu4N-{Mo132} in films increases with the increasing amount of incorporated Bu4N-{Mo132}, while the third-order nonlinear refractive index n 2 decreases. Experimental results prove the high stability of Bu4N-{Mo132} in PMMA films in inorganic acidic and basic solutions. These studies indicate that Bu4N-{Mo132} in thin solid films of PMMA are potential candidates for fabricating nonlinear optical devices.