Title page for etd-0722114-223155


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URN etd-0722114-223155
Author Wan-Lin Chen
Author's Email Address No Public.
Statistics This thesis had been viewed 5560 times. Download 35 times.
Department Electro-Optical Engineering
Year 2013
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title The nonlinear optical properties of graphene by Z-scan technique
Date of Defense 2014-07-16
Page Count 85
Keyword
  • Nonlinear Refraction (NLR)
  • Nonlinear Absorption (NLA)
  • Z-scan
  • Two Photon Absorption (TPA)
  • Saturation Absorption (SA)
  • Graphene
  • Optical Kerr effect (OKE)
  • Abstract In the thesis, we used Z-scan technique to study the nonlinear optical properties of graphene saturable absorber. The light source employed in this study is frequency doubled, Q-switched and mode-locked Nd:YAG laser. As for the samples, we took advantage of CVD method to grow atomic layer graphene, and acquired different layers, which are 1-, 8-, and 16-layers.
    By injecting an ultrafast, picosecond, 532 nm wavelength Nd:YAG laser into the above-mentioned three samples, and using different laser pulse energies to measure and investigating various nonlinear optical effects of graphene. Through Z-scan experiment, we measured the nonlinear absorption and nonlinear refractive optical coefficient for different layers graphene material.
    As a result, the nonlinear absorption coefficient α(I) and nonlinear refractive index n(I) are obtained as 0.468 to 3.563 (108 cm-1) and 0.733 to 5.506 (108 cm-1), respectively. Compared with other semiconductor materials, graphene grown by CVD method has large nonlinear parameters. In addition, we concluded that the nonlinear effects might not be resulted from two photon absorption. The main source of absorption is the saturation of single photon absorption. But for graphene with more layers or defects under intensity exceeds 40 GW/cm2, TPA mechanism might be involved.
    Advisory Committee
  • Tai-huei Wei - chair
  • Chao-Yung Yeh - co-chair
  • Hsin-Hui Kuo - co-chair
  • Pi-Ling Huang - co-chair
  • Wood-Hi Cheng - advisor
  • Files
  • etd-0722114-223155.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2014-08-22

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