D.Y. Guan

Publications (3)3.84 Total impact

• Source

  Available from: iphy.ac.cn

  Article: Picosecond nonlinear optical responses of Au/PVP composite films

  Hong Shen, B L Cheng, G W Lu, D Y Guan, Z H Chen, G Z Yang
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  ABSTRACT: Nonlinear optical properties of colloidal Au and poly(vinylpyrrolidone) (PVP) composite films were investigated using the Z-scan technique with 25 ps pulses at 532 nm near the surface plasmon resonance frequency of Au nanoparticles. Experimental results show large optical nonlinearities of the composite films with the real and imaginary parts of the third-order nonlinear optical susceptibility χ (3) being 4.7 × 10 −10 esu and 2.5 × 10 −10 esu, respectively. The obtained χ (3) value of Au/PVP composite films is comparable or higher than that of the organometallic complexes reported. Furthermore, a strong optical limiting response was observed and a possible application of the composite films as an optical limiter of picosecond laser pulses was discussed.
  J. Phys. D: Appl. Phys. 01/2006; 39:233-236.
• Article: Resonant absorption quenching and enhancement of optical nonlinearity in Au:BaTiO3 composite films by adding Fe nanoclusters

  W. T. Wang, Z. H. Chen, G. Yang, D. Y. Guan, G. Z. Yang, Y. L. Zhou, H. B. Lu
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  ABSTRACT: We present an approach to enhance the figure of merit χ⁽³⁾/α (with χ⁽³⁾ being the third-order nonlinear susceptibility and α the optical absorption coefficient) in metal-dielectric composites. Nanocomposite thin films containing metal nanoclusters were obtained by embedding gold, or gold+iron in BaTiO ₃ matrices using the pulsed laser deposition technique. In the optical absorption spectra, the Au:BaTiO ₃ films showed a strong absorption peak around 562 nm due to surface plasmon resonance of Au particles. However, when a small amount of Fe was added, the resonant absorption was quenched, and χ⁽³⁾ was enhanced so that χ⁽³⁾/α was significantly increased. Our study suggests a method by which to design optical nonlinear materials with large figure of merits for practical application. © 2003 American Institute of Physics.
  Applied Physics Letters 10/2003; · 3.84 Impact Factor
• Source

  Available from: l03.iphy.ac.cn

  Article: Nonlinear optical properties of thin iron films grown on MgO (100) by pulsed laser deposition

  W.T. Wang, D.Y. Guan, G. Yang, G.Z. Yang, Y.L. Zhou, H.B. Lu, Z.H. Chen
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  ABSTRACT: Thin films of iron were fabricated on MgO (100) substrates using pulsed laser deposition technique. The crystalline property and surface roughness of the films were investigated by X-ray diffraction and atomic force microscopy, respectively. It was found that the morphology of the Fe film deposited at room temperature was characteristic of continuous metal film. Increasing the deposition temperature caused the smooth Fe film to break up, and nanoscale Fe islands were formed. We performed the z-scan measurements to study the third-order optical nonlinearity of the continuous approximately 9-nm-thick iron film. The results show that the ultrathin iron film exhibits large nonlinear refractive coefficient, n2=7.09×10−5 cm2/kW, and nonlinear absorption coefficient, β=−5.52×10−3 (cm/W), at the wavelength of 532 nm.
  Thin Solid Films.