Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (08): 1985-1989.doi: 10.3866/PKU.WHXB20110818

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Second Harmonic Generation Properties of Centrosymmetric Bisphthalocyaninato Thulium in Langmuir-Blodgett Films

LIU Yun-Long1, WANG Wen-Jun1, GAO Xue-Xi1, XU Jian-Hua2   

  1. 1. School of Physical Science & Information Technology, Liaocheng University, Liaocheng 252059, Shandong Province, P. R. China;
    2. State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, P. R. China
  • Received:2011-04-06 Revised:2011-05-31 Published:2011-07-19
  • Contact: WANG Wen-Jun E-mail:phywwang@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (10874063), Key Project of Science and Technology of Shandong Province, China (2010GGX10127) and Shandong Province Higher Educational Science and Technology Program, China (J10LA60).

Abstract:

The second order nonlinear optical properties of sandwich thulium bisphthalocyanine (TmPc2) molecule Langmuir-Blodgett (LB) films were investigated using the second harmonic generation (SHG)method. The dependence of the second harmonic intensity on the incident angle of the fundamental beam was measured and the mechanisms of nonlinearity were discussed briefly. The experimental results indicated that the second harmonic signal intensity was very strong and its maximum was obtained at an incident angle of 45°. The second order nonlinear optical susceptibility χ(2) was about 1.152×10-8 esu and the hyperpolarizability β was about 1.905×10-30 esu. By measuring the polarization properties of the second harmonic signal for the LB film and comparing this with the theoretical analysis, we found that the origin of the second harmonic generation was attributed to the electric quadrupole mechanism for the TmPc2 molecule.

Key words: Terbium bisphthalocyanine, Langmuir-Blodgett film, Nonlinear optics, Second harmonic generation, Electric quadrupole mechanism